Haha no probs :).
I'll start with a question:
Treatment of water- the whole aeration to chlorination thing. I can never remember it. Is there an easy (creative?) way to remember it or do i just have to know it? Could someone also put it down below and ill try to make a mnemonic out of it or something hehe ;D
Thanks all
Does anyone understand what refraction of light has to do with myopia and hyperopia??Your eye has a lens and cornea which are responsible for refraction of light onto the rods and cones of the retina and this is at the FOCAL POINT. The rods and cones are responsible for colour and shade vision. In hyperopia and myopia, the FOCAL POINT occurs further than the retina or before the retina (respectively), and so images cannot be made properly. In order for proper images to form, the focal point must be at the retina.
Does anyone understand what refraction of light has to do with myopia and hyperopia??
Does anyone understand what refraction of light has to do with myopia and hyperopia??
Hi Dtinaa
Refraction of light is how light bends when entering mediums of different optical densities
In the eye, the lens, aqueous humour and vitreous humour refract light onto the retina.
When it refracts in front of the retina, myopia occurs, which means that objects that are far away are not focused properly (usually due to the eyeball being to long for accommodation to properly focus)
When it refracts behind the retina then hyperopia occurs, where the objects that are closer become blurry (usually due to the lens becoming less elastic due to age).
Hope this helps
Skidous
Can anyone please explain to me introns and exons? It's part of the option module code broken - still confused as to the difference between exons and introns.In DNA, you have introns and exons. Exons code for proteins or polypeptides, whilst the introns are just non-coding segments which interfere with coding genes and are GENERALLY useless (the reason I say generally is because there's been some research into why introns are present).
Thanks
Just to add onto what StudyBuddy wroteAh okay awesome - will do! Thankyou so much :))
You should also talk about the reduced effectiveness of quinine over the years as well as the development of plans to try and prevent malaria through controlling mosquito populations, this is another dot point but it would be good to refer to it
Hey liizThis was super helpful, and yep - definitely summarised rather than made my notes longer!! Short but good information in there that hopefully I'll be able to remember a bit easier. Thankyou so much for helping out, really appreciate it :))
Gather and process information..
This means that youll need to be doing more than simply 'identifying' (soz if going all BOSTES on you :p)
The main points of malaria: (soz its a bit long got carried away :p)
Around 2700 BC - several characteristic symptoms of malaria were described in the Nei Ching, Chinese medical writings. The Greece recognised it by 4 B.C. as the cause of the decline of many city populations. Hippocrates noted the principal symptoms.
Around 18 BC- Romans discovered malaria was common in marshy areas around Rome. The name malaria is derived from the Italian for “bad air"
Quechua healers of South American tribes in the Amazon used the bark of the Cinchona shrub to treat fevers and diseases
In the 1600s, this was observed by Spanish priests, who started using it to treat fevers associated with malaria. By 1649, the bark was available in England. The active ingredient, quinine, was isolated in 1820 by Pierre Joseph Pelletier. Quinine is one of the most effective anti-malarial drugs today.
In 1880, Charles Laveran, a French army doctor, observed the malarial parasite. He was awarded the Nobel Prize for his work in 1907.
In 1886, Golgi observed asexual reproduction in the protozoan Plasmodium and identified two species.
In 1897, Ronald Ross discovered the malarial parasite in the stomach of an Anopheles mosquito. The parasite is the protozoa of the genus Plasmodium transmitted by the female Anopheles mosquito. In 1902, Ronald Ross won the Nobel Prize in Medicine for this achievement.
In 1898, Giovanni Grassi named the Anopheles mosquito as the carrier of the malarial parasite.
In 1934, Hans Andersag discovered chloroquinine, a synthetic drug. He named the compound resochin. Chloroquinine is an effective and safe antimalarial, though it was not recognised as such by British and American scientists until 1946.
In 1942, Paul Muller discovered the insecticide DDT. It was first used in Italy in 1944, and idea of global eradication of malaria seemed possible. Subsequently, widespread systematic control of the Anopheles mosquito has been used to interrupt its lifecycle, including the spraying of DDT, coating marshes with paraffin, using mosquito nets and draining stagnant water. However, mosquito populations developed resistance to DDT, making DDT have minimal or no effect
I feel like I have gone on for ages but the main points are in bold
Hope that has actually summarised rather than extended your notes! ;D
This was super helpful, and yep - definitely summarised rather than made my notes longer!! Short but good information in there that hopefully I'll be able to remember a bit easier. Thankyou so much for helping out, really appreciate it :))No worries im glad i was able to help :D nice to see that some people dont think i ramble on too much (my english teacher thinks otherwise.. :p)
Hey guys!
I'm gonna drop a few questions for Search for Better Health here. Any answers would be appreciated!
1) What were MacFarlane Burnet's contributions to our understanding of the immune response and the effectiveness of immunisation programs?
2) What are the interactions between B and T cells and what are the mechanisms that allow these interactions?
3) What are the main features of epidemiology?
Thanks!
The purpose of this forum, as I see it, is to help refine your understanding, so please to try to avoid just dumping questions and expecting people to answer them, especially when, such as in the case as question 1, you could just as easily Google it.
So before I contribute to answering any of those, what do you think? What have you found by doing your own research? Then we can help refine it.
could someone please explain to me the difference between enatiostasis and homeostasis?enatiostasis is the the maintenance of metabolic and physiological functions in response to variations in the environment.
thanks
To add onto what Sine said, you should also have an example of each.
Enantiostasis: Mangroves Trees active accumulated salt on older leaves in order to prevent the salt from building up in other cells, the salt is removed when the leaves fall off.
Homeostasis: Aldosterone is activated when the blood pressure and ion concentration in blood is too low in order to actively absorb more sodium ions and stabilise blood pressure
My guess is that you need 2 examples. These include the
Osmoregulators: organisms that avoid changes in their internal environment and have the ability to keep the solutes at an optimal level (‘regulate’ solute concentrations within the body), regardless of the differing external environment. i.e Mussels close their mouths in order to keep the salt levels in their tissues the same as sea water
Osmoconformers: organisms that tolerate the changes in the environment by altering the concentration of their internal solutes to match the external environment. i.e the fiddler crab accumulates salt into its tissues to match seawater and pumps out the excess when exposed to fresh water.
You should also talk what estuaries are and what change in the environment that requires enantiostasis to occur for these organisms to live in their ecosystems
Them feels man, them feels. English trials are over though so that means only the "easy" subjects are left. Y'know, physics, chemistry, maths, SOR II and Bio
I don't mean to brag but I'll have you know that I came third in SOR II and I barely did study for all 3 assessment tasks
Could someone please explain the mechanisms that allow interaction between B and T cells?? (INCLUDING MHC molecules?)
The major histocompatibility complex (MHC) is a set of cell surface proteins essential for the acquired immune system to recognize foreign molecules in vertebrates. so you would refer to them basically as the protein flags which determine whether a cell is self or non-self (and consequently an antigen)
Ohhhhh, thanks dude!!
No problem man, always happy to help
For some extra information there are 2 types of MHC molecules
MHC II can be conditionally expressed by all cell types, but normally occurs only on professional macrophages and B cells, used primarily to assist in antibody mediated immunity (Humoral Immunity)
MHC I occurs on all nucleated cells—in essence all cells but red blood cells—and presents epitopes to killer T cells, also called cytotoxic T lymphocytes. CD8 receptor on Cytotoxic T-cells docks to MHC I molecules, if they fit together it triggers the cell to undergo programmed cell death by apoptosis, hence assisting with Cell Mediated Immunity (addressess intracellular pathogens, such as viruses and some bacteria)
That's correct I forgot to add that in, didn't know about the dendritic cells however
So basically they're like B-Cells and Macrophages, but in the lumph and are the most important part of the specific immune response, right?
Hmmmm, kind of. B-cells, macrophages and dendritic cells are all called antigen-presenting cells, because they can present antigen on MHC class II molecules.
The role of the dendritic cell is to sit in the lymph and activate T-cells. They really are the cell responsible for activation of T-cells.
Macrophages and B-cells present antigen not so much to activate T-cells, but rather, to get help from them.
Hey Bparker
1: Lipids are transported in the body in the form of Glucose, Amino acids, Fatty Acids and Glycerol, Nucleotides.. Glucose and Amino Acids enters the bloodstream through water (water soluble) and then dissolves in the plasma.
Lipids (Fatty Acids and Glycerols) Only some enter the bloodstream directly, whilst most need to be packaged into small droplets which pass the lymphatic system into the bloodstream.
2: When justifying whether an experiment is appropriate you need to consider what is being tested by the question and whether the experiment actually is trying to test the same thing. IF that is the case then you need to go into the validity, reliability and accuracy of the experiment. These points also have to be explained (using cause and effect language)
Hey Bparker
1: Lipids are transported in the body in the form of Glucose, Amino acids, Fatty Acids and Glycerol, Nucleotides.. Glucose and Amino Acids enters the bloodstream through water (water soluble) and then dissolves in the plasma.
Lipids (Fatty Acids and Glycerols) Only some enter the bloodstream directly, whilst most need to be packaged into small droplets which pass the lymphatic system into the bloodstream.
2: When justifying whether an experiment is appropriate you need to consider what is being tested by the question and whether the experiment actually is trying to test the same thing. IF that is the case then you need to go into the validity, reliability and accuracy of the experiment. These points also have to be explained (using cause and effect language)
As usual, thanks for doing such a good job on this forum Skidous!
Just going to jump in on this one though. Lipid≠glucose≠amino acid≠nucleotide.
Lipids include things like sterols (including cholesterol), triglycerides and phospholipids. Glucose is a carbohydrate, amino acids are the building blocks of proteins and nucleotides the building blocks of nucleic acids. If you mean to say that lipids are used as substrates in the synthesis of these things, of course you would be exactly right; however, once they are turned into these things they cease to be lipids.
You did correctly identify how lipids are transported around the blood stream. They are packaged into small droplets, with proteins to hold them in together. They can, however, be directly placed into the bloodstream without having to worry about the lymph (only when lipids are absorbed do they travel in the lymph).
Thankyou vox nihili! Are these droplets you're referring to called chylomicrons?Yeah they're chylomicrons
Yeah they're chylomicrons
Sorry about that, it must have gotten most up with my notes on digestive products
Thankyou vox nihili! Are these droplets you're referring to called chylomicrons?
Question Time!
Does anyone know of an Australian Biologist current working in the field? and if so what work are they doing?
Thanks Ragdolls, could you maybe go into a little more depth into what exactly he does?
Thanks that's all I needed, big help, hope to see you on the forums some more.
Hey. I just wanted to ask if anyone could please help me understand the parts of the brain from the Communications Option. I'm unsure which section of the brain is responsible for what...Unfortunately I have not covered this part in the content yet :(
Hi, I was just wondering, if a gene I'd recessively sex linked on the X chromosome (males get) are those males then encouraged not to reproduce or even perhaps the mother of the child with the disease encouraged not to reproduce again.
Thanks
P.S. Not trying to offend anyone just wondering because I got a question that asks how to prevent someone with this disease from passing it on to further generations. If they are "allowed" to reproduce how else would they prevent the passing on of the disease to future generations
Hey. I just wanted to ask if anyone could please help me understand the parts of the brain from the Communications Option. I'm unsure which section of the brain is responsible for what...
It's a question about what sections of the brain are responsible for each process with regards to receiving and interpreting stimuli (sound, sight, smell, taste, touch)
Hi Vox, yeah sorry i should've made my understanding clearer i was more talking about the kids of the daughters he had being affected. I didn't make that clear at all, my bad. Thanks for the extra info as well
For future notice, true just copying out the question that was asked so there is less confusion
Hey anotherworld2b
I don't think this is in the Biology Syllabus since there isn't any need for bio students to know the hormonal regulation for ovulation/menstruation cycle.
I did find a video that may assist though
https://m.youtube.com/watch?v=RFDatCchpus
If this doesn't help then I'm sorry, but you may wanna head over to the Senior Science Board or another science related board for more assistance
Hope this helps
Skidous
hey i was wondering if anyone did/does communication what are the functions of each section of the brain?Different lobes:
and whats action potential?An action potential is the changing of electrical potential in a neuron which happens as a result of neuron de/polarisation. The potential travels down the axon of a neuron and causes changes in the electrical charge/polarity. An action potential can trigger a pre-synaptic neuron to release neurotransmitters to diffuse across a synaptic gap, which bind to receptors in post-synaptic dendrites. (This is a pretty simplistic overview. I didn't do hsc or vce bio so I'm not sure what details you need to know exactly)
How many past papers is recommended before hsc?
Having trouble with this dot-point:I have two examples for this dot point:
9.3.4.1 - Discuss evidence for the mutagenic nature of radiation
Can anyone help me out?
I have two examples for this dot point:
1) Survivors of the bombings of Hiroshima and Nagasaki (which occurred in 1945, towards the end of World War II) suffered physical mutations as a result of the radioactive output of the nuclear explosion. Children born to survivors showed many defects, in particular a microcephalic condition (development of a very small head and failure for brain to grow)
2) In 1926, H. G. Muller performed an experiment in which he irradiated the reproductive cells of fruit flies. He found that the irradiated flies had an incidence of mutation 150 times higher than control flies that had not been irradiated. If he reduced the dosage, the frequency of mutations also decreased. His experiments provided direct evidence of the link between exposure to ionising radiation and mutations.
There's a lot more evidence to prove the mutagenic nature of radiation but I just stick with these two because they're pretty easy to remember. Hope this helps!
With reference to the dot point in maintaining a balance - "Compare response of named Australian ectothermic and endothermic organisms to changes in ambient temp and explain how these response assist in temp regulation", is an adaptation the same as a response or are they different?
I was doing the 2015 HSC biology paper and I was confused with Q26: sugar is transported in vascular tissue in plants and animals. Contrast the structure and workings of ONE named plant tissue and ONE named animal tissue used to transport sugar. And I'm not sure how to answer the animal tissue portion of the question and would love help, cheers :)
From what I understand, the response is a result of the adaptation. From my example, the Red Kangaroo places it's tail underneath it's body when the ambient temperature rises to reduce SA:V ratio, and decrease heat absorption from the sun - the behavioural adaptation allows for the response (placing tail under body) in order to decrease temperature and regulate temperature. So they are kind of two peas in a pod to an extent.
Happy to clarify if this doesn't make sense aha.
hi guys, could someone explain to me the difference between cell mediated immunity vs anti-body mediated immunity? thanks
whats the different between a B and T cell?
Hey can someone please help me with questions 19 and 20, I've attached them
Thanks
Hello, I'm probably wrong in these answers and I'm not really a reliable source of help but I tried the questions:
For Q.19 I chose A because basically it would take time to produce the enzyme. If it was gradual, as one enzyme denatures, another one may be on its way to be produced. If it was a rapid change, all the currently functioning enzymes would die out and as it takes time to produce enzymes, there wouldnt be any enzymes that would maintain metabolic activity and the fish would die??
For Q.20 I thought maybe it would be B: the change in temperature in the environment affects the production of the enzymes (the phenotype being the ability to produce four enzymes at different temperatures??)
Not D: because the case study doesn't really say anything about the body temperature of the fish and it only talks about the temperature of the environment, A: because the case study doesn't mention substrates, C: it's not really a limitation for the fish if they can still survive at such a wide temperature variation as long as the four enzymes can still function respective of their temperature ranges.
"idk tho"
Please correct me if I'm wrong haha I tried ;D
Hey guys I got a question. When we are solving sex-linked inheritance do we always assume that the X chromosome is the one carrying condition and never the Y chromosome?
Hey guys I got a question. When we are solving sex-linked inheritance do we always assume that the X chromosome is the one carrying condition and never the Y chromosome?
I'm not particularly clear on what you're expected to know in HSC, but of course sex-linked inheritance could involve genes on the Y-chromosome. Pretty much as easy as it gets though. Passed from father to son to son to son to son to son to son, can't skip a generation, never seen in females blah blah
For the verb "Design", for example "design an experiment", do you only provide a procedure or do you give aim, hypothesis, procedure, equipment, results and variables?
The whole thing! Not just the method. Aim, hypothesis, equipment, variables, risk assessment and method.
You might not have the results - particularly if it's an experiment that you have not done. In this case, do not include any.
For the verb "Design", for example "design an experiment", do you only provide a procedure or do you give aim, hypothesis, procedure, equipment, results and variables?
There is actually a part of the syllabus right at the beginning which is all the skills for science (with regards to research and pracs) so to add onto what Naomi said you should look into those as well to make sure you answer the question properly
Okay so for example for the question:
A new product has been developed to kill pathogens in drinking water.
Design an experiment to test the effectiveness of the product.
(4 marks)
Would I say:
Hypothesis: there will be less pathogens remaining in the sample of water after the product has been applied.
Aim: to test the effectiveness of the new product
Method: .....
Im conflicted as to what i would write for the hypothesis as the question states that it is a "new product" so how can you make an educated guess?
(Most Hypotheses have a format of If (independent variable) then (dependent variable) Because (explanation/reason))
Also what would the method be?
Also, when you write the method, can you do it in number point form or do you have to describe it?
Also, when you write the method, can you do it in number point form or do you have to describe it?
What do you need in your method though? As in, what are the critical factors that make a good experiment?
Also the equipment should be in dot points and include measurements
I.e if you need water for plants state 200ml of water
But if you have 5 plants and they need 200ml every day for a week then it would be
5x1000ml of water and then in the method state how much you need per day (sorta like a shopping list you state the total amount used for one and how many times you need that amount)
Hope this Helps
Always number form! It's a list of steps, like cooking.
Also no that there is less than a month till hsc bio exam, what do you do for study?
You should revise absolutely everything
This includes practical and Research tasks
You should also try to do as many past papers as possible
If you want some help with study check out this
http://atarnotes.com/forum/index.php?topic=161208
Okay so are past papers enough or do I have to go and rewrite my notes ( they have said to rewrite notes in every forum so far but i want to know if it is actually necessary, arent past papers enough?)
Okay so are past papers enough or do I have to go and rewrite my notes ( they have said to rewrite notes in every forum so far but i want to know if it is actually necessary, arent past papers enough?)
I definitely don't think you should be re-writing notes now. If you are still revising notes, supplement it by practising past paper questions like me.
It's fine to rewrite notes now, we still have 2 weeks till the biology exam as the HSC isn't a one week set of exams it take up to 4 weeks. If you feel like you want to consolidate your information a little further then you can rewrite notes but summarise. Even if it's just the stuff you don't know quite yet it's still a good way to review.
Not to say that past papers aren't good for study, they are, but some people need that extra bit of work before they can get stuck into their work.
Also it is best to hand write these new summary notes as you will remember it better if you write it by hand
I definitely don't think you should be re-writing notes now. If you are still revising notes, supplement it by practising past paper questions like me.
Alright thank you! I procrastinated way too much during the year and as a result am entirely not prepared for the hsc so i guess whatever happens, happens. But thanks for the help!
For HSC the method just needs to describe the steps carried out in the experiment, it should have specific steps/instructions into how it should be carried out and what needs to happen there aren't any really critical factors other than making sure the experiment is reasonable and could be carried out in a laboratory of school standard (so not being something that isn't possible if done by a school like using the Large Hadron Collider)
I get that procrastination happens (trust me I did my last 2 bio assessments (that weren't trials) in 2 days before they were due and I still topped) but what matters now is putting in heaps of effort to get the best mark possible, that includes asking for help like on these forums
Essentials in regards to an experiment? Usually BOS get an experiment question about plants, etc. How can I, under 10 minutes figure out a procedure??That will depend on the question being asked, with pracs it is usually related to one of the Dot points in the syllabus so the method would be very similar to an experiment you've probably already done in class. If you haven't done an experiment like the one given in class then make one up that seems appropriate and can test what is being asked of you.
What are some key scientific words that should be used consistently in short answers/long responses
For a question like:You would need to talk about the cause of lung cancer and then link it to cancer deaths in Australia.
Describe the occurrence, symptoms, cause and treatment/management of a named non-infectious disease. (5 marks)
For the occurrence part, is it enough to say, "lung cancer is the leading cause of death due to cancer in Australia"? Or do I have to give more stats?
Also, what would the mark distribution be for this questions?
You would need to talk about the cause of lung cancer and then link it to cancer deaths in Australia.
You will need to know statistics for occurrence as that is the purpose for understanding occurrence, this will include numbers and demographic of the infection (age, gender, socio-economic status etc.)
As for mark allocation
1mrk for Name of Disease
1mrk for correct occurance
1mrk for correct description of symptoms
1mrk for Correct description of cause
1mrk for correct description of treatment and management
Potentially 1mrk for coherent and concise response
Hope this Helps
Hey I was just wondering how exactly Burnet discovered immunological tolerance, like did he inject fetuses with diseases? I can't really find much info and I'm so confused haha, Question 2: How does the creation of hybridisation and transgenic species reduce genetic diversity, aren't you essentially making a new species? Thanks !!
Hey I was just wondering how exactly Burnet discovered immunological tolerance, like did he inject fetuses with diseases? I can't really find much info and I'm so confused haha, Question 2: How does the creation of hybridisation and transgenic species reduce genetic diversity, aren't you essentially making a new species? Thanks !!Immunology tolerance wasn't discovered by Burnet, it was him that discovered the method by which humans gain their acquired immunity, I don't know the logistics of this but he did research into the 3 lines of defence.
Immunology tolerance wasn't discovered by Burnet, it was him that discovered the method by which humans gain their acquired immunity, I don't know the logistics of this but he did research into the 3 lines of defence.
PS: given this is an HSC biology thread it would remiss of me to not remind you that Macfarlane Burnet was born, educated and worked all of his life in Victoria :p
I know but we unfortunately can't use him as an example for an Australian biologist.I don't have one yet. When was the last time they asked for a male or female scientist in the HSC?
Speaking of which, I have a question. What is your Male and Female Named Scientist working in the field of biology? I would really like a name and the work they have done in biology
I don't have one yet. When was the last time they asked for a male or female scientist in the HSC?
ADH and adolsterone. Please, I need this to be explained in a more alleviated form!
What diseases are caused by lack of adh or aldosterone?
Aldosterone: Conn syndrome or death. If you have a complete absence of aldosterone, you'll die within days
Have there been any productions in artifical blood in australia?Not entirely sure but I know that you don't need an Australian example, just an example of artificial blood and what it does, why it's important and what it doesn't do that real blood does
Not entirely sure but I know that you don't need an Australian example, just an example of artificial blood and what it does, why it's important and what it doesn't do that real blood does
Could you please give me an example?
Abstract
This report will examine the production of artificial blood. Including its advantages/ disadvantages, clinical trials of a chosen blood substitute as well as the reasoning as to why the blood substitute could potentially be an effective substitute and why blood substitutes are needed in the first place.
Introduction
Artificial blood is the name given to a substance used to mimic and fulfill some functions of biological blood, although it cannot carry out all functions of blood, for example it cannot, help clotting, immune defence or coagulation. Although it can carry carbon dioxide and oxygen.
Blood substitutes are designed to carry oxygen and carbon dioxide. An ideal blood substitute should lack antigenicity and eliminate, or at least substantially reduce, the ability to transmit infections. In addition, it should be readily available, should have a long half-life, and should be capable of being stored at room temperature. The biologic properties of an ideal blood substitute should include a reasonable amount of oxygen delivery, when compared to normal human red blood cells.
Example of Blood Substitutes
An example of blood substitutes is maleimide-polyethylene glycol hemoglobin (MP4). MP4 is currently under development in the UK and is a blood substitute made of Haemoglobin obtained from out-of-date human blood and modified using maleimide-polyethylene glycol in order to make the molecule bulkier as well as altering shape of the molecule. By doing this MP4 has a great oxygen affinity which is essential for a blood substitute. MP4 being a blood substitute does not, however, provide many other functionings of blood such as the clotting and immune defence.
Clinical Trials
MP4 has undergone many clinical trials on pigs and some humans in order to test its effectiveness of transporting oxygen as well as its ability to assist in the recovery of hemorrhaging without causing vasoconstriction. These trials have shown successful results in the ability of MP4, however more research is needed in order to prove whether or not it is ready to be used on humans as an effective blood substitute.
Why is it needed?
Blood substitutes such as MP4 are needed due to the fact that there are many obstacles that need to be overcome that are associated with blood donation. Donors of blood are required in order for a supply of blood to be given to those who need it. There is a deficit of people willing to donate their blood and thus a substitute is needed due to the fact that more blood is needed in hospitals to treat patients as a result of blood having a relatively short shelf life and there not being as many donors to replace all the unused blood donations. The development of MP4 allows for the blood to be in ready supply to treat patients such as providing blood to those who are extremely anaemic with blood transfusions. With the development of and eventual use of MP4, there would not be an issue with the amount of blood received from blood donations as it can be synthetically produced in labs to provide treatment to those who need it as well as MP4 having a relatively long shelf life so that it can be ready to use even after an extended period of time.
Blood received from donors goes through a screening process in order to ensure that there are not antigens and other possible diseases that are present within the blood. There is a risk that some of the blood may contain blood-borne pathogens such as HIV, AIDS and Hepatitis-C when donated. As a result of this, the development of MP4 is essential for society in order to reduce the risk of pathogens such as HIV from being unintentionally passed on due to screening of donor blood missing pathogens within them and thus providing safe blood transfusion and blood usage during surgery for patients.
Conclusion
Artificial Blood is better known as Blood substitutes as they only perform some of the functions of blood such as the transportation of oxygen and carbon dioxide. The development of the blood substitute MP4 has shown promising potential due to its high affinity for oxygen shown through clinical trials. This development is beneficial for society as it allows for potential use for the blood substitute as a means of providing doctors and patients with a ready to supply source of blood for surgeries and transfusion without running the risk of possible blood-borne pathogens being present within the sample.
My class got given a research project for this as an activity
I think lack of aldosterone can also lead to Addison's disease
Other way round. Addison's disease is a problem with the adrenal glands, that usually leads to low aldosterone (but more prominently, leads to low cortisol).
What is the control used in the pasteur swanneck flask experiment?I believe it would be the flask that is open to the air and microbes.
What is the control used in the pasteur swanneck flask experiment?
Hey guys so i'm that confused with the difference b/w meiosis and mitosis, could someone please explain it? :)
I believe it would be the flask that is open to the air and microbes.
Mitosis: refers to the duplication of cells; involved in the repair, growth and replacement of cells.THANK YOU SO MUCH!
- Parent cell differentiates --> two genetically identical, diploid daughter cells formed.
Meisos: refers to the differentiation of cells to form sex cells, which are involved in the production of offsprings (and heredity).
- Parent cell differentiates --> 4 genetically different, haploid daughter cells formed.
Alright so when i write the method, do i say "have one straight necked flask as a control"?
Precisely; just talk about preparing two flasks followed by the insertion of a swan glass 'tube' in one flask's stopper and a straight glass 'tube' (control) in the other.
Okay but what is the reasoning behind the straight necked flask being the control?
Mitosis: refers to the duplication of cells; involved in the repair, growth and replacement of cells.
- Parent cell differentiates --> two genetically identical, diploid daughter cells formed.
Meisos: refers to the differentiation of cells to form sex cells, which are involved in the production of offsprings (and heredity).
- Parent cell differentiates --> 4 genetically different, haploid daughter cells formed.
Just to further this point
Meiosis begins when the chromosomes of the parent cell quadruple their chromosomes (haploid (23) --> Double Diploid (46 pairs)
Meiosis is also important for genetic diversity in 3 steps
1: Chromosomes cross over with their homologous pairs at a chiasmata and trade genetic information (this creates new alleles)
2: Independent alignment: The chromosomes themselves randomly align along the equatorial plate (there is no order in which the diploid chromosomes align on one side AND they do not have to match up with their homologous pairs) when they separate into 2 DIPLOID Cells
3: Random Segregation: The Chromosomes randomly segregate into different halves of the cell when the 4 HAPLOID cells are formed.
Since these gametes are all random when they are formed, there is also the benefit of random fertilization as there no NATURAL way to ensure one gamete fertilizes another gamete to produce a specific offspring, this furthers genetic diversity
NB There are reproductive technologies such as In Vitro Fertilization (IVF) and Pre-Implantation Genetic Diagnosis (PIGD/PGD) that can ensure that one games fertilizes another and produces an offspring that is healthy or without any genetic disorders or illnesses
Just gonna jump in and clear up a couple of minor points. As normal you know your stuff well, but meiosis is a little bit tricky.Isn't the parent cell for a gamete just another gamete? Or is it another type of cell?
That the parent cell quadruples its chromosomes seems to imply that the parents start off with a haploid set of chromosomes. This is obviously not the case.
The parent cell starts off with 46 pairs of chromosomes. It then undergoes replication. It does not, however, double the number of chromosomes. It doubles the number of chromatids. This distinction is really critical.
3. as you've described is not a source of variation. Only the first meiotic division generates variation. You correctly identified independent assortment, during prophase I, as a means of generating variation. Independent alignment just means that the chromosomes line up in the middle randomly, from which they are segregated into the daughter cells randomly as well. After that there are no other sources of variation; so all the variation exists after the first division. The second operates just like mitosis.
Isn't the parent cell for a gamete just another gamete? Or is it another type of cell?
i have three questions:
1. what's the difference between ADH and Aldosterone?
2. what is the role and function of the kidney?
3. what is the hormone replacement dot point about?
thank you in advanced
Most of the questions I'm answering can be easily found in the textbook or internet.Just to add onto this for 3 you need to also talk about what the hormone replacement is for those who have Addison's disease or when they cannot produce ADH
Anyways:
1. Both are hormones, except ADH (anti-duretic hormone) is involved in water retention, whilst aldosterone is involved in salt (e.g. sodium) retention.
2. The kidney is generally involved in homeostasis - it removes excess substances and waste (i.e. nitrogenous waste) and is involved in osmoregulation (salt/water levels).
3. Basically talk about the importance of each hormone and the negative effects it has on an individual if missing (e.g. No ADH = dehydration, No aldosterone = addison's disease).
It's an oversimplification we are supposed to know what Addison's disease actually is but some people simplify it to mean there is no aldosterone
I came across this question in 2013 paper from genetics section "analyse how the understanding of mechanisms of genetic change has influenced the use of genetic technology in society"
Right so a couple of marks in the marking guidelines are allocated for "relates understanding of genetic change to the use of genetic technology"
Could someone shed some light here I got stuck there in terms of formulating my "knowledge" to respond to what they're asking
cheers
i was looking at the 2004 HSC question and was unsure on how to answer q24. "JUSTIFY CONTINUED RESEARCH INTO THE DEVELOPMENT OF ARTIFICIAL BLOOD." Can anyone please explain to me what exactly is artificial blood and how it can be incorporated into this kind of question. I looked at the answers and didn't like the way it was explained.
Thank you in advanced
I came across this question in 2013 paper from genetics section "analyse how the understanding of mechanisms of genetic change has influenced the use of genetic technology in society"
Right so a couple of marks in the marking guidelines are allocated for "relates understanding of genetic change to the use of genetic technology"
Could someone shed some light here I got stuck there in terms of formulating my "knowledge" to respond to what they're asking
cheers
i was looking at the 2004 HSC question and was unsure on how to answer q24. "JUSTIFY CONTINUED RESEARCH INTO THE DEVELOPMENT OF ARTIFICIAL BLOOD." Can anyone please explain to me what exactly is artificial blood and how it can be incorporated into this kind of question. I looked at the answers and didn't like the way it was explained.
Thank you in advanced
hey, I was hoping someone could explain to me how to go about answering this question. Essentially how to structure the response and what details are exactly needed to satisfactorily answer it?
"Scientists have tried to achieve a viable embryo by fusing two ova (eggs) from the same female.
Explain whether the offspring produced using this process would be a clone of the female whose two ova were used. Use your knowledge of gamete formation and sexual reproduction to support your answer."
Also I am pretty hopeless at the Kidney stuff so I would greatly appreciate if someone could explain the role of the kidney in the excretory system of fish and mammals and how it all works in simple terms?
Thank you in advanced!! :) :)
can anyone explain chromosomes to me i always get confused with it
chromosomes in general
chromosomes in general
Gene homologues and gene cascades. Why. Just why.
I really struggle with those 7 or 8 mark questions at the end of the code broken that have vague mentions of technology and genetics and genetic change and development. What kind of things are really core to understanding gene homologues and gene cascades and how they fit within all those 8 mark questions?
i feel your pain, i have no clue as to how i should be answering any 5-6-7 questions
Really hoping for a recombinant DNA/Human genome question. Anything but the last dotpoint :(
then how does the chromosome study relate to Boveri and Sutton? is it because they discovered that chromosomes are required for the normal production of DNA in the body?
then how does the chromosome study relate to Boveri and Sutton? is it because they discovered that chromosomes are required for the normal production of DNA in the body?
i feel your pain, i have no clue as to how i should be answering any 5-6-7 questionsFor any 5-8mrk question you should be analysing the question and breaking it down to be see what they're asking of you and then writing your response. Question that ask to discuss, assess, evaluate should make sure your points are explained.
Hey Skidoos, do you think you could re upload that report you did on Artificial Blood?Artificial Blood Report
im so sorry Skidous, my computer must have autocorrected your name to Skidoos instead i apologise profusely but thank you so much for the report.No problem I've had it happen before :)
No problem I've had it happen before :)
On behalf of all of the atarnotes community, we sincerely hope you can recover from this mispronunciation - all hail king skidous! ;D ;D ;D
First question: the answer is basically that it does not produce a clone of the female whose ovaries were combined.
- Refer to Boveri's experiment with sea urchins: he discovered that if only the nucleus of one parent was present, it would result in abnormalities (not 100% sure why but probably due to chromosomes not being transferred properly).
- Refer to how crossing over, independent assortment and random segregation during meisos results in a different and unique genetic makeup to that of the parent cell within each daughter cell produced.
Second question:
- the kidney is fundamentally involved in homeostasis; it removes excess substances and nitrogenous waste that is either not needed by or toxic to the body, or reabsorps substances needed by the body for optimal functiong (e.g. salt and water).
- For how it works, are there any specific areas/concepts you are unsure about? The process itself can't be simplified other than the fact that blood enters it, reabsorption occurs throughout and the left over bits are excreted as urine.
Hopefully this helps :).
Thanks so much!What year is this question from?
In terms of the kidney I just don't understand what the steps are i guess, in terms of the mammalian kidney. I've read over some content on it but i guess it just isn't sticking. Is there anyway of remembering the steps and each part of the nephron that it occurs in?
What year is this question from?
Im having trouble with answering this question:
People can have problems with communication because of difficulties in the sending, receiving or interpretation of some signals. How has an increased understanding of sight and hearing led to improved assistance for people with difficulties in communicating? 7 marks
Actually my problem doesnt lie within what to write but how to make it concise. My answer for this goes for way too long and i think for 7 markers the average should be 1-1.5 pages right? Anyways if anyone could show me a band 6 response to show me how to include all the relevant info for 7 marks while keeping it in a concise form, that would be great!
Thanks so much!
In terms of the kidney I just don't understand what the steps are i guess, in terms of the mammalian kidney. I've read over some content on it but i guess it just isn't sticking. Is there anyway of remembering the steps and each part of the nephron that it occurs in?
This diagram had really helped me out when it came to understanding the kidney:
(https://i.gyazo.com/b97c7f4d8971d518f96809ead4e8d368.png)
Picturing/memorising the kidney like this and following the movement of blood through it can really help.
Well to be concise you would tackle each of these responses separately and only include very necessary information. There really isn't much else other than ensuring that the info you write is really necessary and using specific examples to get your point across
Hope this helps
But what is relevant or necessary to put in?That will come down to the question itself
would you guys recommend knowing the meiosis diagram? or any particular diagrams?I highly recommend it (the diagrams on page 168 from the Chidrawi biology textbook are pretty decent).
would you guys recommend knowing the meiosis diagram? or any particular diagrams?Here are a few from my textbook that I used, they're pretty good
Here are a few from my textbook that I used, they're pretty good
legend! thanks skidoos :pNP
Not a question but just a reminder
THE HSC REQUIRES YOU TO USE BLACK PENS
If any of you guys who still have to buy pens and other materials for the exam please keep this in mind to make sure you don't waste your moneys
Good luck to all for the English Exams coming up and then the Bio exam after that :)
Thanks for the reminder!! I actually forgot that new rule. Does anyone know now that they are scanning exam whether we still draw diagrams in pencil or do we have to do them all in pen now??I am pretty sure it said on the trials "Draw diagrams using pencil" but who knows. I would pack a pencil in your little clear ziplock bag or whatever you do (and an eraser, a sharpener and another pencil- no use spending half the exam trying to sharpen up a pencil thats snapped)
I am pretty sure it said on the trials "Draw diagrams using pencil" but who knows. I would pack a pencil in your little clear ziplock bag or whatever you do (and an eraser, a sharpener and another pencil- no use spending half the exam trying to sharpen up a pencil thats snapped)
If it doesnt say it on the front, then draw using pen. If it does, draw it using pencil. My biology teacher said you actually dont get penalised for doing diagrams in pen, but if you make a mistake, it is much easier to rub out pencil rather than leaving the marker scrambling all over the exam to see where you did in pen and crossed it out.
Just a word of advice from one bio student to another, and good luck everyone! (May the odds be ever in your favour :D)
You should draw diagrams in pencil yes but everything else should be black pensEverything else HAS to be in black pen. No excuses. If it gets scanned in to the markers and they cant read it because you have put it in pencil, you dont get marked. That simple.
I thought that there weren't many people asking this question except me and there wasn't much response to it I'd help everyone out
Australian Biologists
Male
George L Gabor Miklos, PhD: Founder of Atomic Oncology, Sydney, Australia
Holds a PhD in Genetics and has extensive laboratory experience in diverse biological disciplines. He has provided advice to international firms and individuals in the areas of advanced molecular technologies and clinical trials, including being an advisor to the Human Genome Project conducted at CELERA.
His current interests take in the multiple uses of laser ablation-based diagnostics in various neoplasms, clinical trials of prostate cancer screening, detection and drug treatments of breast cancer, the mechanisms of radioresistance in different organisms, and the stability of Attractor Basins in normal versus tumorous tissues. He is an outspoken advocate for complete data release and transparency in clinical trials. George Miklos’ disclosures of potential conflicts of interest relating to Atomic Oncology.
Female
Denisse Leyton: PhD in Microbiology
She studied at Monash University on autotransporters, a superfamily of bacterial outer membrane proteins typically found in bacterial pathogens responsible for infectious diseases such as diarrhea, whooping cough, cholera, chlamydia, and bacterial meningitis. Here she identified two novel autotransporter proteins and determined how their function contributed to bacterial virulence. Denisse then moved to the University of Birmingham (UK) for a post-doctoral position where her research efforts focused on the mechanisms underpinning autotransporter secretion
At The ANU, Denisse and her research group will focus on understanding the mechanisms of autotransporter assembly, their function, and on their reengineering for biotechnological applications.
Hopefully this information can be useful and assist in your studies and get you out of a tight pinch if it turns up in this years HSC
Hope this Helps
Lol thanks :D now i just have remember it all as well 160 or so other dot points in eleven days. (Not meaning to be sarcastic at all)
Should get me a few marks though just knowing the names :P
hey there bud, what dot point requires australian biologists? i don't recall any
hey there bud, what dot point requires australian biologists? i don't recall any
Hey guys could someone simplify the move of materials in xylem and phloem. I'm having trouble understanding this dotpoint.
Hey guys could someone simplify the move of materials in xylem and phloem. I'm having trouble understanding this dotpoint.
Hey guys could someone simplify the move of materials in xylem and phloem. I'm having trouble understanding this dotpoint.Xylem: Cohesion-Adhesion-Tension Theory
How well does someone have to perform in Biology to hit band 6's because a previous student was getting band 6's all year and performed really well in the HSC but did not get band 6 at the end of the yearThat shifts around year to year but a scaled mark of around 90 is a band 6 but that mark of 90 can change depending on how every student does on that particular exam that year and then the marks are shifted. I.e. 2014 band 6 may be 95 but 2015 band 6 may be 87.
Can anyone help me with myopia and hyperopia. Im quite confused because from what I understand is that myopia results from an elongated eyeball but I thought to see long distance objects you needed a elongated eyeball and for close objects a more rounded eyeball? So if it results from an elongated eyeball, shouldn't there be a longer focal length and thus the image would fall behind the retina not in front?If your eyeball is elongated the the refractive powers of the relaxed lens would not be sufficient to refract the light into the retina but just in front of it (the lens is only part of the eyeball) and thus causing the image to be blurry when light from an object enters the eye from a far distance which I known as myopia (short-sightedness)
Thank you
Xylem: Cohesion-Adhesion-Tension TheoryI'm still confused on the phloem part. Is sugar still being moved in step 3? In step 2 the sugars are already actively transported to the areas of the plant where they are needed. Shouldn't the theory end here?
Step 1: Water enters the plant through the root hairs via osmosis
Step 2: As a water molecule transpires in the leaves, another one is ‘pulled up’ the column of water in the xylem by the negative pressure (tension) created to replace it.
Step 3: Another water molecule enters the plant by osmosis at the bottom of the xylem to replace the one that was lost through transpiration.
Cohesion is prevalent through the water molecules sticking together, adhesion is the water molecules adhering to the cellulose molecules of the xylem wall.
Phloem: The Pressure-Flow Theory
Step 1: Loading at the Source
Amino acids, sucrose and other mineral nutrients are loaded into the phloem in the leaves. There are two theories as to how this may occur:
1. symplastic loading—sugars and other nutrients move in the cytoplasm from the mesophyll cells to the sieve elements through plasmodesmata (strands of cytoplasm that pass through pits in the cell walls)
2. apoplastic loading—sugars and nutrients move along a pathway through the cell walls until they reach the sieve element. They then cross the cell membrane to enter the phloem tube. These sugars pass into the sieve cell by active transport.
As sugars enter the phloem, the phloem sap becomes more concentrated and so the osmotic pressure at the source end is high. This draws water into the phloem, from the adjacent xylem tissue, by osmosis
Step 2: Offloading at the sinks
Materials flow to the sink. At the sink (for example roots, flowers or any other parts of the plant that need nutrients), sugars and materials are removed from the phloem by active transport.As sugars move out of the phloem, they draw water out with them (by osmosis). This results in a lower osmotic pressure (due to the higher water concentration) in the phloem at the sink region.
Step 3: Pressure Flow
This difference in osmotic pressure between the source and the sink in the phloem drives the phloem sap to flow. The direction of flow depends on where the sink areas (roots or flowers) of the plant are, in relation to the source (leaves). Water can move into the phloem by osmosis at any point along the gradient. The flow is continuous, because sucrose is continually being added at one end and removed at the other
Hope this helps
Not a question but just a reminderShould post that impact size 36 font elsewhere so that EVERYONE can see it, not just biologists.
THE HSC REQUIRES YOU TO USE BLACK PENS
If any of you guys who still have to buy pens and other materials for the exam please keep this in mind to make sure you don't waste your moneys
Good luck to all for the English Exams coming up and then the Bio exam after that :)
Should post that impact size 36 font elsewhere so that EVERYONE can see it, not just biologists.
Yes it should be I just didn't know where that place wasHSC discussion thread will do lol
I'm still confused on the phloem part. Is sugar still being moved in step 3? In step 2 the sugars are already actively transported to the areas of the plant where they are needed. Shouldn't the theory end here?
Hey what did you mean by 'lose marks for things i didnt even know i needed'?
Hey!
For example it would be a four mark question, and 2 of the marks were allocated to an example... but the question never said provide or give an example.
There was also a two marker in trials about "IDENTIFYING" Darwins impact on evolution or something, and i talked about natural selection and survival of the fiitest blah blah blah, yet i only got one mark because i didnt mention his journey/ work with the darwin finches. Like i knew what that was, but i didnt think it was neccessary for a two mark identify question.
Does that make sense? hahaha
Hey!
For example it would be a four mark question, and 2 of the marks were allocated to an example... but the question never said provide or give an example.
There was also a two marker in trials about "IDENTIFYING" Darwins impact on evolution or something, and i talked about natural selection and survival of the fiitest blah blah blah, yet i only got one mark because i didnt mention his journey/ work with the darwin finches. Like i knew what that was, but i didnt think it was neccessary for a two mark identify question.
Does that make sense? hahaha
If your eyeball is elongated the the refractive powers of the relaxed lens would not be sufficient to refract the light into the retina but just in front of it (the lens is only part of the eyeball) and thus causing the image to be blurry when light from an object enters the eye from a far distance which I known as myopia (short-sightedness)
When dealing to looking at objects close up and far away it is actually the lens that changes shape not the eyeball. This is known as Accommodation
When an object is closer, the light scatters more from that object, hence the ciliary body contracts which causes the suspensory ligaments to loosen and thus cause the lens to increase in curvature and achieving maximum accommodation.
When an object is further away, the light from the objects are more parallel, therefore the ciliary body relaxes, causing the suspensory ligaments to tighten and thus decreasing the curvature of the eye and minimum accommodation.
Hope this helps
I'm still confused on the phloem part. Is sugar still being moved in step 3? In step 2 the sugars are already actively transported to the areas of the plant where they are needed. Shouldn't the theory end here?No as the sugar is describing how it enters one sink not other sinks
Hmm I'm not excellent at Biology, but isn't the pressure flow theory a continuous process in the plant? Sugar is still being continuously added and removed, which also affects the water pressure
Does anyone have any Maintaining A Balance HSC exam questions or practice papers?
Also,
Any tips for how to prepare for/do well in a biology practical Assessment task?
Thank you!!
Does anyone have any Maintaining A Balance HSC exam questions or practice papers?Hi there,
Also,
Any tips for how to prepare for/do well in a biology practical Assessment task?
Thank you!!
For this question (5 marks):
Explain the relationship between replication of DNA and evolution.
Do I have to describe the process of DNA replication (helicase etc.) or no?
You would probably refer to some of the DNA replication process but then link that to the meiosis process because it talks about DNA and evolution
hmm would you not talk about evolution as in mutations which changes the dna, which then gets replicated aswell?
hmm would you not talk about evolution as in mutations which changes the dna, which then gets replicated aswell?
Hey:)
So I was just doing a past paper where it said that Mendel's monohybrid cross was of tall pea plants x short pea plants. we were always taught that it was smooth peas x wrinkled peas. if i were to get a question that didnt specify what cross mendel did, and asked me to outline his experiment, what should i do? is it ok to just go with what i was originally taught?
Yeah thats what i thought... but also, why would you talk about meiosis? Its asking about dna replication, not just dna itself
Before meiosis takes place, the DNA replicated within the cells to produce the increased number of chromosomes within the nucleus before the meiosis begins, hence why you can talk about it and you can then talk about the different types of alleles that are made and how those are then replicated to promote variations and therefore evolution
Mendel actually did several experiments not just those 2. They were
Pea Shape (smooth or wrinkled)
Pea Colour (yellow and green)
Pea Pod Colour (Yellow and green)
Pea Pod Shape (Smooth or constricted)
Stem Length (tall or short)
Flower Colour (white or pink)
Pea/Flower (not too sure of which one) positioning (Axial [along the whole stem] or Terminal [just the top])
If asked to outline his experiment you would choose on of the traits, preferably the one you know the best. Then proceed to describe the experiment. Always do what you know best if it was what you were taught. You don't need to stress about knowing all 7 traits but knowing the experiment and knowing which trait was dominant and recessive should suffice.
Hope this helps
For dependent variable is "characteristics of microbe colony growth on agar plate" an acceptable answer?
Also could you guys explain what the control would be? My excel book says "Temperature/volume medium" so I think they are getting it mixed up with controlled variables. The Bostes answers say "sterilised water" which I'm not exactly too sure why.
For dependent variable you would be looking at microbial growth in general not necessarily the characteristics of it.Thanks for the insight. But for the control, you said it is to confirm whether or not there are contaminants on the agar plate that produce microbes. Could an agar plate just by itself be a control as well?
The control for this experiment would be sterilised water as you want to confirm whether or not the agar plates were contaminated.
What your textbook described was a controlled VARIABLE and not a controlled experiment where no independent variable is added (sterilised water would not promote microbial growth)
Hope this helps
Thanks for the insight. But for the control, you said it is to confirm whether or not there are contaminants on the agar plate that produce microbes. Could an agar plate just by itself be a control as well?
skidoos! talking about meiosis can you help me out with this question?
What are the sizes of the red and white blood cells and the units we measure them in?They're measured in micrometres (μm). Red blood cell is approx 6-8 μm and white blood cells are approx 10-12 μm
What are the sizes of the red and white blood cells and the units we measure them in?
They're measured in micrometres (μm). Red blood cell is approx 6-8 μm and white blood cells are approx 10-12 μm
White blood cells (more specifically neutrophils which make up 70% of the white blood cells in our body) are 12-15 μmI guess so but I was taught WBC were 10-12 μm
Hey, i have a contradicting set of notes. The ones i wrote earlier this year, have that the blood becomes de-oxygnated at the Kidney, but my other sets says there is an increase of oxygen in the blood around the kidney...Oxygen levels in blood will decrease after it passes the kidney. Your first set of notes are correct. According to my notes, carbon dioxide is the only chemical that increases after blood passes through the kidney.
see my problem, which one is correct??
THANK YOU x
How many pages should you be writing for 7 and 8 markers in the exam? I know in the core topic, it gives you one page usually for the 7/8 marker but usually for all of the questions you need more lines, so how many pages is the optimal number? Also for the option topic, where there is no line indication, how many pages should we write for the long responses?
Oxygen levels in blood will decrease after it passes the kidney. Your first set of notes are correct. According to my notes, carbon dioxide is the only chemical that increases after blood passes through the kidney.
I guess so but I was taught WBC were 10-12 μm
Oxygen levels in blood will decrease after it passes the kidney. Your first set of notes are correct. According to my notes, carbon dioxide is the only chemical that increases after blood passes through the kidney.
Just to add onto this the only place where oxygen should increase in blood, according to my knowledge, is in the lungs where the oxygen mixes with the blood and removes CO2. Everywhere else in the body oxygen in the blood should be decreasing as cells take oxygen for respiration
Ok, cool, thanks.
does that mean Co2 rises in the blood when it goes past the lungs??
The CO2 lowers when it goes past the lungs and increases when it passes through all other organs
Hey:)
Are the marker molecules on the surface of transplanted organs which cause an immune response referred to as antigens or is it that they have a different MCHI molecule?
Also, one of the focus areas for the search for better health topic refer to a scientist called Macfarlane Burnet but I dont seem to have any notes on him. Is there anything specific we need to know about him?
I'm not 100% about that first part but I can try and answer your second question. There is technically no dot point on Burnet which is probably why you don't have any notes on him, i myself only got a short paragraph intro into him when my class went through search for better health but i guess all you would really need to know about him is that he made a significant contribution to the understanding of the immune response. He investigated the reason why the immune system can respond to foreign substances without destroying its own cells in the process and concluded that immunity is gradually acquired over the course of foetal development. He did this by introducing foreign cells to foetus in utero and noted that these foreign cells were not rejected.
He also used chicken eggs to develop a way to isolate spcific viruses - allowing for creation of vaccines like the influenza vaccine
Hey, i have another question. I know fish produce ammonia. However, im not sure if ammonia needs a loy of water to be produced?
Hey:)
Are the marker molecules on the surface of transplanted organs which cause an immune response referred to as antigens or is it that they have a different MCHI molecule?
Also, one of the focus areas for the search for better health topic refer to a scientist called Macfarlane Burnet but I dont seem to have any notes on him. Is there anything specific we need to know about him?
Marker molecules are actually protein flags on all of the tissues within the body. The reason why an immune response occurs is due to the fact that invading foreign bodies (not necessarily pathogens) have different sets of these flags (different types, too many, too little or none at all) and that triggers an immune response as the body detects the antigen as 'Non-Self'
When an organ is transplanted that isn't similar to the patient's tissue type or when a person who has had a transplant stops taking immunosuppressants then the immune response attacks the organ.
The protein flags themselves are not antigens but the human immune system recognises them as non-self and will treat the organ as though it is an antigen.
Hope this helps
Marker molecules are actually protein flags on all of the tissues within the body. The reason why an immune response occurs is due to the fact that invading foreign bodies (not necessarily pathogens) have different sets of these flags (different types, too many, too little or none at all) and that triggers an immune response as the body detects the antigen as 'Non-Self'Thanks! That helped heaps:)
When an organ is transplanted that isn't similar to the patient's tissue type or when a person who has had a transplant stops taking immunosuppressants then the immune response attacks the organ.
The protein flags themselves are not antigens but the human immune system recognises them as non-self and will treat the organ as though it is an antigen.
Hope this helps
Hi again:)Hey imtrying,
In the Communication topic there's a dot point that says a nerve is a bundle of neuronal fibres. Are neuronal fibres just neurones?
Hey imtrying,Thanks!
These are sometimes also called axons, but in essence neuronal fibres and neurones are the same thing.
If we want to get specific: a neurone consist of axons, cell body and dendrites. So a neurone consists of neuronal fibres.
This may lead to the question: what is an axon? Simply put axons take information away from the cell body.
Hi!
I was wondering if you could explain the difference between prevention and control in terms of malaria?
I personally believe prevention has to do with vaccines and control with other measures such as mosquito nets and appropriate clothing. But
couldn't some control measures be regarded as prevention as well? Sorry, I've just gotten confused...
Thanks in advance!!
Hi!
I was wondering if you could explain the difference between prevention and control in terms of malaria?
I personally believe prevention has to do with vaccines and control with other measures such as mosquito nets and appropriate clothing. But
couldn't some control measures be regarded as prevention as well? Sorry, I've just gotten confused...
Thanks in advance!!
Hey imtrying,
These are sometimes also called axons, but in essence neuronal fibres and neurones are the same thing.
If we want to get specific: a neurone consist of axons, cell body and dendrites. So a neurone consists of neuronal fibres.
This may lead to the question: what is an axon? Simply put axons take information away from the cell body.
when it comes to the electrochemical changes that occur in the membranes of neurons, what initially stimulates the movement of ions?
also, i noticed that extra clarification on my last question, thanks:)
hi,
when a dotpoint say 'process information from secondary sources', does that mean that they'll provide information in the exam which we interpret, or do we have to go in with info already memorised to answer the question?
thanks!
hi,
when a dotpoint say 'process information from secondary sources', does that mean that they'll provide information in the exam which we interpret, or do we have to go in with info already memorised to answer the question?
thanks!
Very sorry to keep asking questions in different posts...im finding the neuron thing a bit confusing.
Whats the go with synapses and neurotransmitters? Would i be right in saying that when the impulse reaches the synapse at the end of the axon, a neurotransmitter is released and this allows the electrical impulse to be changed to a chemical one as it crosses the synapse and then back to electrical impulse at the dendrites?
Precisely. Except, that the neurotransmitter diffuses to the next dendrite and stimulates a new, but same electrical impulse at the dendrites.
Very sorry to keep asking questions in different posts...im finding the neuron thing a bit confusing.
Whats the go with synapses and neurotransmitters? Would i be right in saying that when the impulse reaches the synapse at the end of the axon, a neurotransmitter is released and this allows the electrical impulse to be changed to a chemical one as it crosses the synapse and then back to electrical impulse at the dendrites?
Is it concerning that my class is also doing communication yet I am not understanding any of this?? Honestly the only thing that makes sense to me from that topic is the eye and ear stuff...
HEYY GUYS!
I have a few bio MC questions to ask, i dont understand why i got them wrong so here goes ...
An extremely high concentration of carbon dioxide is undesirable in active muscle tissue
because it will
(A) increase the pH.
(B) cause enzymes to denature.
(C) increase cellular reaction rates.
(D) cause haemoglobin to release oxygen.
My answer was D, which im pretty sure is right BUT the answers said B???
The following measures could be used to prevent the spread of this fruit fly across
Australia.
1. Australia-wide release of infertile fruit flies
2. Aerial spraying of orchards throughout the country
3. Spot spraying of newly affected orchards in Western Australia
4. Stopping the transport of fruit from Western Australia to other states
To prevent the spread of this fruit fly across Australia, which combination of measures
would be most practical to use?
(A) 1 and 2
(B) 1 and 4
(C) 2 and 3
(D) 3 and 4
I put B because I though of prevention, which includes the use of genetic engineering... doesnt it? but the answers says D
If someone can help differentiate between control, prevention and treatment. That would be great :)
Why might epidemiology be considered more essential for the study of non‑infectious
diseases than for the study of infectious diseases?
(A) The causes of infectious diseases have already been determined.
(B) Only non‑infectious diseases are affected by patterns of behaviour.
(C) Epidemiology cannot be used to find the causes of infectious diseases.
(D) Koch’s postulates are not useful in finding the causes of non‑infectious disease
How the hell is it D ???
Students conducted a large first-hand investigation into enzyme activity.
The aim in the report is shown.
Aim: To determine the optimum pH of four different enzymes.
How many independent variables were in this first-hand investigation?
(A) 1
(B) 2
(C) 4
(D) 5
For an experiment to be valid shouldnt it change ONE variable at a time, then how come the answer is B
Also q. 17 from the 2015 paper, how is C not D
VERY MUCH APPRECIATE ANY HELP :)
HEYY GUYS!
I have a few bio MC questions to ask, i dont understand why i got them wrong so here goes ...
An extremely high concentration of carbon dioxide is undesirable in active muscle tissue
because it will
(A) increase the pH.
(B) cause enzymes to denature.
(C) increase cellular reaction rates.
(D) cause haemoglobin to release oxygen.
My answer was D, which im pretty sure is right BUT the answers said B???
The following measures could be used to prevent the spread of this fruit fly across
Australia.
1. Australia-wide release of infertile fruit flies
2. Aerial spraying of orchards throughout the country
3. Spot spraying of newly affected orchards in Western Australia
4. Stopping the transport of fruit from Western Australia to other states
To prevent the spread of this fruit fly across Australia, which combination of measures
would be most practical to use?
(A) 1 and 2
(B) 1 and 4
(C) 2 and 3
(D) 3 and 4
I put B because I though of prevention, which includes the use of genetic engineering... doesnt it? but the answers says D
If someone can help differentiate between control, prevention and treatment. That would be great :)
Why might epidemiology be considered more essential for the study of non‑infectious
diseases than for the study of infectious diseases?
(A) The causes of infectious diseases have already been determined.
(B) Only non‑infectious diseases are affected by patterns of behaviour.
(C) Epidemiology cannot be used to find the causes of infectious diseases.
(D) Koch’s postulates are not useful in finding the causes of non‑infectious disease
How the hell is it D ???
Students conducted a large first-hand investigation into enzyme activity.
The aim in the report is shown.
Aim: To determine the optimum pH of four different enzymes.
How many independent variables were in this first-hand investigation?
(A) 1
(B) 2
(C) 4
(D) 5
For an experiment to be valid shouldnt it change ONE variable at a time, then how come the answer is B
Also q. 17 from the 2015 paper, how is C not D
VERY MUCH APPRECIATE ANY HELP :)
HEYY GUYS!
I have a few bio MC questions to ask, i dont understand why i got them wrong so here goes ...
An extremely high concentration of carbon dioxide is undesirable in active muscle tissue
because it will
(A) increase the pH.
(B) cause enzymes to denature.
(C) increase cellular reaction rates.
(D) cause haemoglobin to release oxygen.
My answer was D, which im pretty sure is right BUT the answers said B???
The following measures could be used to prevent the spread of this fruit fly across
Australia.
1. Australia-wide release of infertile fruit flies
2. Aerial spraying of orchards throughout the country
3. Spot spraying of newly affected orchards in Western Australia
4. Stopping the transport of fruit from Western Australia to other states
To prevent the spread of this fruit fly across Australia, which combination of measures
would be most practical to use?
(A) 1 and 2
(B) 1 and 4
(C) 2 and 3
(D) 3 and 4
I put B because I though of prevention, which includes the use of genetic engineering... doesnt it? but the answers says D
If someone can help differentiate between control, prevention and treatment. That would be great :)
Why might epidemiology be considered more essential for the study of non‑infectious
diseases than for the study of infectious diseases?
(A) The causes of infectious diseases have already been determined.
(B) Only non‑infectious diseases are affected by patterns of behaviour.
(C) Epidemiology cannot be used to find the causes of infectious diseases.
(D) Koch’s postulates are not useful in finding the causes of non‑infectious disease
How the hell is it D ???
Students conducted a large first-hand investigation into enzyme activity.
The aim in the report is shown.
Aim: To determine the optimum pH of four different enzymes.
How many independent variables were in this first-hand investigation?
(A) 1
(B) 2
(C) 4
(D) 5
For an experiment to be valid shouldnt it change ONE variable at a time, then how come the answer is B
Also q. 17 from the 2015 paper, how is C not D
VERY MUCH APPRECIATE ANY HELP :)
ohhhh, thank you so much!!!!!!!!!
But still have 1 q. how does pH lead to denaturing, i thought it was only temperature...
ohhhh, thank you so much!!!!!!!!!
But still have 1 q. how does pH lead to denaturing, i thought it was only temperature...
disrupts the hydrogen bonds
Thanks for answering my previous question. Im wondering now, if Mendel's "factors" reffered to the 'gene' or the 'allele'. Different websites seem to be saying different things...
Hi guys, just having a bit of trouble understanding the difference between hybridisation and transgenic species?
I know its really simple but I just don't understand haha, cause I keep getting multiple choice questions wrong for it
Thanks
Hey guys
Quick question. Is comparative DNA sequencing the same thing as DNA hybridisation??
No, DNA Sequencing is just the sequencing of the base pairs.Wait aren't you describing DNA sequencing still?
DNA Hybridisation is matching up the DNA from 2 different species and testing the matches and mismatches (less=closely related) and the difficulty in separation (increased difficulty = closely related)
Hey guys so I have always been confused on how to draw transverse and longitudinal sections of phloem and xylem tissue. Can someone please show me how to draw them? Because I always get them wrong :-X
Hey guysFYI DNA sequencing can be part of BP1 where you have to analyse how advances in technology have changed scientific thinking about evolution. It allowed scientists to find similarities between humans and apes, thus a closer evolutionary relationship.
Quick question. Is comparative DNA sequencing the same thing as DNA hybridisation??
Wait aren't you describing DNA sequencing still?
Wait aren't you describing DNA sequencing still?
Okay that makes sense but then how is comparative DNA sequencing used in biochemistry to show evolution?I don't know if you saw my other post. But scientists will compare the bases of DNA strands from two different species. The more similar the bases are, the more closely related the two organisms are with each other. This supports common ancestry and thus evolution.
I don't know if you saw my other post. But scientists will compare the bases of DNA strands from two different species. The more similar the bases are, the more closely related the two organisms are with each other. This supports common ancestry and thus evolution.
Transverse
(http://uploads.tapatalk-cdn.com/20161017/427c6d523e21e6f4688baeaba01a9bd0.jpg)
Longitudinal
(http://uploads.tapatalk-cdn.com/20161017/0742dd2b824fc2774de7bec4259fbba6.jpg)
Both
(http://uploads.tapatalk-cdn.com/20161017/b3e658b9ffd0b8b5b61bdf5e9310cae7.jpg)
An easy way to remember
Transverse is circular
Longitudinal is rectangular
So which parts are the xylem and phloem?
Yeah that's DNA hybidisation right?Oh I see what you mean, I've been taught DNA sequencing involves the comparison. In that case, I would think they're the same thing.
So what is Comparative DNA sequencing? Isn't it the same thing?
Sorry I'm so confused right now
Oh I see what you mean, I've been taught DNA sequencing involves the comparison. In that case, I would think they're the same thing.
Oh I see what you mean, I've been taught DNA sequencing involves the comparison. In that case, I would think they're the same thing.No they're different
No they're different
Comparative DNA sequencing does not include the combination of DNA Strands, just looking at the differences in the sequencing themselves. So I just looks at the base pairs
Oh okay so how is that used in biochemistry as evidence for evolution?
Hello, can you please explain the answer to this question. The answer is D.
:)
Is biochemistry an option or is it a technology
As a technology if the sequenced chemicals are similar then that shows that they will exhibit similar traits and thus show evolutionary links between organisms
Okay thanks. Biochemistry is a branch of scientific study which is used to support evolution, so DNA sequencing would be a technology.
Thanks again!
Hey
So the reason it's D is because the movement of ions is AGAINST the concentration gradient (should be high to low concentrations when this one goes from low to high) which requires energy, hence it's active transport
Hi!Chromatids contain DNA and Chromosomes are comprised of 2 chromatids joined at the centromere
So i'm kinda confused on the concept of DNA replication. I don't get why it happens in meiosis, i know its for heredity and for genetic information to be passed on, but i don't understand the concept behind it, like all the chromosome and chromatid stuff.
Thanks :)
Hi everyone
looking for hsc biology past papers organised by questions according to the topics
i know there are some available online but would anyone have just a list?
thanks
I know it's the technology just weren't sure if it was an option topic
ohh no it comes under Blueprint of Life
Yeah i know it does just wanted to clarify
Whats stopping BOSTES from asking a question worth more than 8 marks??? :'(
Whats stopping BOSTES from asking a question worth more than 8 marks??? :'(
okay cheers, was just imagining the HSC discussion group post an exam with a 20 marker in it ;D
okay cheers, was just imagining the HSC discussion group post an exam with a 20 marker in it ;D
Hahaha the memes and posts on that group can be hilarious at times but can also be terrifying lol just gotta filter out the irrelevant stuff sometimes
Yeah but it's a good way to relieve stress
True, #WhaleBoats #ButterflyDarts #FiveThousandLightYearsAway
LOL never going to look at a boat or whale the same way ;DSad thing is I actually don't mind walking, but I would never write an article about it.
#walkingforpleasure
Sad thing is I actually don't mind walking, but I would never write an article about it.
Especially since the guy was named Sam Wright who is a COMEDIAN
True and no visual :O
Does anyone understand the polypeptide and how it's formed!! I get extremely confused with this aspect!! I know that there is a ribosome which 'sticks' the amino acids together to form a polypeptide. I don't even think that's right! can someone please help
Thanks in advance!!
Hi, I was wondering if we need to know all the scientific names for animals/plants etc that we use for examples?
Thank you
The ribosomes can bring in chains for anticodons with correspond to the codons with produce polypeptides, the chain begins with an STA amino acid and ends with a TER amino acid (terminate)
mRNA is produced when the RNA helicase unravels the DNA one rung at a time, then RNA polymerase transcribes it into mRNA
This leaves the nucleus and heads to the ribosome where it translates the mRNA into polypeptides in codons (groups of 3 base pairs) with corresponding anticodons which are free floating and release a specific polypeptide when the codon and anticodon reacts.
There are some codons that code for the same polypeptide as well.
Hope this helps
The ribosomes can bring in chains for anticodons with correspond to the codons with produce polypeptides, the chain begins with an STA amino acid and ends with a TER amino acid (terminate)
mRNA is produced when the RNA helicase unravels the DNA one rung at a time, then RNA polymerase transcribes it into mRNA
This leaves the nucleus and heads to the ribosome where it translates the mRNA into polypeptides in codons (groups of 3 base pairs) with corresponding anticodons which are free floating and release a specific polypeptide when the codon and anticodon reacts.
There are some codons that code for the same polypeptide as well.
Hope this helps
Super picky: DNA helicase (it's the DNA being unraveled)
Thank you!! But is there an easier way by any chance! Sorry I know I am a pain atm
Ok, after some further research I've discovered I may be wrong and it may be the RNA polymerase that actually separates the DNA and created the mRNA at the same time. Now I'm just confused
Thank you!! But is there an easier way by any chance! Sorry I know I am a pain atmIf you're still having trouble understanding polypeptide synthesis, I recommend watching some youtube videos. They're very helpful for simplifying complicated biological processes.
RNA polymerase unzips the DNA (Note: does not separate the DNA completely).
Then it starts pairing up the bases with spare nucleotide to form the mRNA (Note: does not attach to the DNA).
For DNA replication:
1. Enzyme helicase unwinds and separates it.
2. Enzyme polymerase pairs the bases up of each strand with spare nucleotide.
In graphing questions, even if it doesnt ask for a line of best fit, do we still do it? And do we do the normal line and the line of best fit as well, and then label it as "line if best fit"?From doing past papers. If they say draw a CURVE of best fit, your line must be curved. So by saying that, if they ask for a LINE of best fit, your line must be straight. If there isn't any clear instruction then you plot the graph normally.
And also, how do we do line of best fits? What are the rules? Because everyone tells me something different
Hi!
Just wondering, roughly how long should we be spending on each section of the bio paper?
Thanks!
hi could someone please answer this question that is really confusing me......
is hybridisation (e.g. CSIRO Mandarins created from Ellendale Tangor and Imperial mandarins) the same this as selective breeding (Mating Freisian Cows with Jersey cows to get the best combination)????????????????
thanks
So unless it asks for a line of best fit, we just do a normal line connecting the points?
And i meant, does the line of best fit have to pass through as many points as possible? Or does jithave to have equal amount of points on top and below the line? Etc.
Has anyone seen any questions about the timeline on malaria or anything where we need to know the history of malaria? Do we even need to know it?
So even if it doesnt ask for a line of best fit, we draw the normal connected dots graph AND a line of best fit?
Do we label it as line of best fit or not?
And does the line of best fit start at the first point and end at the last point?
if asked a question about models for enzyme specificity, would I just talk about the induced fit model because its the more correct one or would I need to mention the lock and key as well?
Just checking if my info in my notes is right - oxygen is carried 95% in oxyhaemoglobin? I don't know if this is the same as just haemoglobin or not oops
Yes, oxyhaemoglobin is the molecule that carries oxygen in blood (it's just the molecule created when oxygen bonds to haemoglobin)Thanks!
Hey guys quick question you know how transgenes are made using bacterial plasmids, I am a bit confused about how it is inserted into a species? For example how do they insert the anti-freeze gene from salmon into strawberries?
Hello !
Just wondering how much do you have to write for an 8 marker?
and also what do you guys do during reading time? like do you answer the multiple questions straight away first? or read the short answers and stuff? what would be the most effective approach for the reading time
Thankyou !
Hello !
Just wondering how much do you have to write for an 8 marker?
and also what do you guys do during reading time? like do you answer the multiple questions straight away first? or read the short answers and stuff? what would be the most effective approach for the reading time
Thankyou !
Heyy, Imtrying :)
They will ask questions about the process by which minerals and sugars are transported in the phloem, so it is better to know the exact process. Since you do know that phloem actively loads at the source through apoploastic and symplastic loading,its really good but in case it becomes a 5 marker instead of a 3 or 4.
You can write that
symplostic loading:. sugars move into the cytoplasm from the mesophyll cells to sieve tube via the plasmodesmata
apoplastic: sugars move to the cell wall to the cell membrane into the sieve tube by active transport
During reading time I usually try to read as many short answer questions as possible and attempt to plan them in my head. Also, if I have any time left I go over my option questions so my mind is set on the content. Apparently you shouldn't read multiple choice, especially considering it is the easiest section a lot of the time and you have enough time to complete it. You usually don't need all the allocated time to complete the M.C questions so you have time to read the question and options carefully in the allocated multiple choice time. Hope that helps!
in my opinion for an eight marker you should be filling up the whole lines given and go beyond them if you have to....just to be sure that you are covering all parts of the question especially since a lot of detail is required......and i always to multiple choice first just because there are sometimes questions that trigger pieces of information that you can use in the short answers and it eases you into the exam
hey :)
I was wondering if some one can tell me what Is the guanine bases in human DNA
is random segregation and independent assortment the same thing?
Hi!I don't know about the vocal chords being longer, but they are more stretched/tighter and yes there is a smaller gap. Also important to know that when air is pushed from the lungs, the vocal chords will vibrate quickly to produce a high pitch sound.
I'm kinda confused on the larynx and the pitch it produces. When its a high pitch will the vocal chords be longer and the gap between the vocal fold is smaller? and vice versa for low pitch?
thankkksss
Hi!
I'm kinda confused on the larynx and the pitch it produces. When its a high pitch will the vocal chords be longer and the gap between the vocal fold is smaller? and vice versa for low pitch?
thankkksss
if asked a question about models for enzyme specificity, would I just talk about the induced fit model because its the more correct one or would I need to mention the lock and key as well?
By the way do we need to know the diagrams for meiosis and mitosis?
By the way do we need to know the diagrams for meiosis and mitosis?
Its possible they may show you a diagram of meiosis and ask you a question relating to what is happening.
_______________________________________________________________________________________________________________________
Also, what are the features of an epidemiological study? :P
Its possible they may show you a diagram of meiosis and ask you a question relating to what is happening.
_______________________________________________________________________________________________________________________
Also, what are the features of an epidemiological study? :P
What is the trend for long response questions (the one at the end) ?
What is the trend for long response questions (the one at the end) ?
Often they ask you about either: technologies and increased understandings (i.e. scientist's contributions) and the implications it has for society and the environment.
Note: they may be specific in regards to the technologies/understandings that should be included (i.e. 2015 = kidney, other ones about reproductive technologies/genetic diversity, natural selection etc).
Also, cheers Skidous.
Now that the exams are done I would like to say congrats to all you bio student, we did jt
Well done!! How did it go? :D
I found it pretty easy, then again I won't know how well I did till December and I finished with an hour left on the time
Legendary. What's next on the exam-menu for you?
Good ol' Mathematics. As my maths teacher told us 'Maths is a wonderful and beautiful thing'
My maths teacher told us "Maths is like god; you just have to believe." ???
But what about the atheists :o
I think that's why I'm so bad at maths.
multiple choice was one of the hardest ive ever encountered
I finished with an hour left on the time
guys OmG i just realised that throughout the bio exam i used shorthand like a triangle to symbolsie the word change and like arrows to show increasing and decreasing if that makes sense.... i know in economics thats alright to use but is it ok in bio exams to use that or am i screwed?!
oh ok thanks!! I was really worried about that! :) thats relief!
hi guys
question
many capillaries are only 6-8 micrometre wide which means
that many red blood cells dirstort into a bell shape (forced to flow in single file)
discuss the advantages of this behaviour?
hi guys
question
many capillaries are only 6-8 micrometre wide which means
that many red blood cells dirstort into a bell shape (forced to flow in single file)
discuss the advantages of this behaviour?
Hey guys. I have an assessment task report coming up. We did a prac on testing enzyme activity with changes in temperature. (amino acids in egg whites with pepsin to be exact). The assignment asks for the usual scientific report, but there's a separate section for presenting the report in some way; powerpoint or video format or whatever, but it's worth 10 marks based on creativity. Any ideas on how to present a prac such as this creatively? Thanks in advance
I'm just wondering how you would approach the question 'what can you conclude from your results and the control experiment?', it's for my bio assignment and the experiment was about the effects of carbon dioxide on the pH of water. I just need some help tackling the question.
If you can! Please and thank you!
hi i'm stuck on this question
direct evidence that sugar is transported in the sieve tubes of the phloem was obtained using radioactive tracers.
eg. plants can be exposed to co2 which contain C14
the plants photosynthesise and the radioactive carbon is incorporated into the
sugars of the plant.
halting the process and taking fine sections which are then covered with fine photographic film
shows the location of the radioactive sugars.
Draw a diagram to show where the autoradiograph would show fogging due to radioactivity
in the stem of the plant..
isn't it just the phloem?
seems to simple for such as a long question...
also i was thinking the source and sink cells but they're not really part of the stem....
any ideas?maybe i'm overthinking it
Hey guys, I have a student research project that is to be conducted through the holiday period. I'm finding it quite difficult to find something i'm interested in. I certainly don't want to grow a plant but I was wondering if you guys have any ideas.
What's the reasearch task about? Is it where you have to create your own experiment based on a hypothesis that you yourself make?
If so, then I actually did mine on shampoo. My aim was to determine which brand of shampoo actually made your hair stronger and so I got fresh samples of my own hair and soaked them in different brands of shampoo's (i.e. Garnier, schwarzkopf etc) and then tested how much strength I used to pulled them until they snapped.
I think it may be but since this is biology I'm not sure if that relates to anything in the biology syllabus.
I think it may be but since this is biology I'm not sure if that relates to anything in the biology syllabus.
[/quote
Ahh that's true, I did that in year 10.
Yeah most SRP are done in year 10 so I'm not sure whether or not there is an experiment you can do as an SRP for bio cause most of my ideas use plants
The SRP is the same as the one in yr10 but in this case it has to be biology related :) It can be anything just as long as it relates to biology
Hi,
I wanted to ask is there a way that enables someone to easily identify a tissue?
Does anyone have any tips?
I have seen a few questions that requires me to identify the tissue and explain why I think so. However, I am quite bad at answering this type of question
Hi,
I wanted to ask is there a way that enables someone to easily identify a tissue?
Does anyone have any tips?
I have seen a few questions that requires me to identify the tissue and explain why I think so. However, I am quite bad at answering this type of question
Hi I am studying the Blueprint of Life topic at the moment.
I was just wondering in relation to the dot point "explain how mutations in DNA may lead to the generation of new alleles."
I am just a bit confused. Is it just because mutations change the DNA base sequence which changes the gene. And since alleles are genes they are therefore different? How would this work in relation to the dominant and recessive alleles?
Thank you
Question,
why are freshwater fish considered hypertonic to their surroundings?
my textbook says this and I am having trouble understanding
hmmm.. could u please explain the difference between hypertonic and
hypotonic pls
Hello!
Anyone have any links to videos that cover the Biology Syllabus?
Thank you :)
Thank you so much :)
The video about kidneys definitely helped.
I did find one website that uploads HSC Bio Videos. It's called HSC Hero
That's cool, videos are a great way to consolidate information, but you shouldn't use them as your only form of study. Study notes are still one of the best ways to study due to muscle memory when you physically write down notes.
Nothing wrong with videos just use them in tandem with your other forms of study
Yeah I definitely agree! I'm just using them to consolidate information. It's also because my teacher isn't the greatest, so I often have to go home and teach myself the content.
I really like your attitude :) It's easy to fall into the trap of blaming your teacher for everything and spending the year whinging about it. Unfortunately, very few just accept the fact and do what's needed to do well (i.e. teach yourself!). :)
Hi :) I was wondering if anyone had tips to remember
1. What chemicals/digestive enzymes are secreted by the liver, stomach, intestine (basically the alimentary canal)
2. Tips to deal with pedigrees
Hey anotherworld,
For 1 I know that the liver has catalase which can break down peroxides into oxygen, as for the stomach it contain sulfuric acid, I'm not quite sure about the intestines
For 2 you should remember a few things
1: Write down Generations (I, II, III, etc.)
2: Have a key (Square for Male, Circle for Female, patterns/coloured in shape for affected)
3: Analyse the relationship between the affected people and the pedigree (i.e. Does it skip a generation, does it only affect men, is it more apparent than the unaffected, can 2 non-affected parents produce and affected offspring etc)
4: Sometimes there will be a question with a paragraph and you have to construct the pedigree, read the question very carefully so you get the right relationships between people and who is affected.
5: Always use a ruler for the lines in a pedigree
6: It may help to write the Genotypes of each person in the pedigree to better grasp how the disease/disorder is passed down generations
Hope this helps
Ok so I am having trouble writing summary notes on the pracs and studying my bio pracs...I just don't know where to start. Any suggestions?? I am currently doing notes for maintaining a balance. Thanks in advance.
Story time.
I have decided to rewrite my biology notes for some random reason (don't ask) and I got a little lost with the first dot point. I know, I'm a genius.
So for 'Identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates', the worksheet says 'Enzymes are proteins made out of amino acids.' I was very happy with such a simple description until I read the next line. 'Proteins are made up of C,N, H, O'
So my question is (after a paragraph of ranting) are amino acids made up of C, N, H, O or are amino acids = C, N, H, O?
Thanks for reading :D
Amino acids are the monomers/building blocks of proteins. So basically proteins are made of long chains of amino acids. Amino acids are made of the elements Carbon, Hydrogen, Oxygen and Nitrogen due to the specific functional groups they are composed of (amine and carboxyl). There are 20 different amino acids that exist so the amino acids do not equal Carbon, Nitrogen, Hydrogen and Oxygen, they are composed of those elements. Amino acids can also contain Sulfur and Phosphorus but all of them must contain C, H, O and N. I'd suggest searching up amino acid on google images so you can visualise the structure.
I'm having trouble understanding T cells and B cells in Search for better health. How do they interact, what happens when they do, what do these cells do and what are the processes involved?
What are actually adenine, guanine, cytosine and thymine? I know together they are codes and together they make nitrogen bases for nucleotides. Are they individual amino acids that comes together to make a bigger amino acids? or like bases?
Thanks :)
Hey guys! I'm not sure about the answers to these discussion questions from the kidney dissection prac. Any ideas?
1. Explain how the colour of each region relates to its blood supply (cortex, medulla, pelvis)
2. Demonstrate, using an analogy, how the kidney functions to excrete waste
Hey guys! I'm not sure about the answers to these discussion questions from the kidney dissection prac. Any ideas?
1. Explain how the colour of each region relates to its blood supply (cortex, medulla, pelvis)
2. Demonstrate, using an analogy, how the kidney functions to excrete waste
All I know for 1, is that the darker the colour of the region, the greater the blood supply to that area. I'm not too familiar with the parts of the kidney (since it wasn't part of last year's biology study design), but I think for this question you need to say that '(name of region) is a darker shade of red, therefore it has a greater blood supply.'
Hello!
I pleading for some help with Enantiostasis and more specifically Osmoconformers and Osmoregulators. I just don't understand the difference between the two.
So some help would be much appreciated, thank you!
Arrivederci!
Good model of a feedback system (MAB module)?? PLEASE & THANKYOU(http://uploads.tapatalk-cdn.com/20170202/93d0977961a0681a68918f74f14657c2.jpg)
could someone help me with this question?
List the advantages of excreting nitrogenous wastes as each of the following: ammonia, urea, uric acid, guanine.
i've been stuck on it for hours haha
Hi all, what is an experiment that models natural selection? One which is not the basic peppered moth example... Thanks! :)
Question: compare the role of haemoglobin in transporting oxygen and carbon dioxide. Having trouble pulling together a succinct answer. Thanks :D
Hey! I'm struggling with this issue in regards to Biology; I can understand the content that is taught to me, and while studying, but find it difficult to answer exam-style questions. How do I overcome this? Thanks :)
Hi thanks in advanced but i am currently really struggling with studying and remembering all the little details in the course that always seem to show up on practice papers. Does anyone have any pointers??
Hey Kirri! I didn't do Bio, but I thought I'd recommend this guide! Hopefully it has a few ideas you can use ;DWow thank you so much i didn't see that before that has some really good points thanks!
Hey Kirri,Thank you, do you normally go through the questions then mark them with your teacher or by yourself?
The only thing I can recommend is to make better notes that cover these points and repeatedly revise these points. Also do more questions on whatever you dont understand. Its better to go through the difficulty now and get it wrong than go through the difficulty and get it wrong in the actual HSC exam :P
hihi!
I'm making notes for 'blueprint' and was wondering if you could check my table I'm wanting to study off
Is there anything I should add or remove/ is anything inaccurate?
Also, how would I go about answering a question regarding this dotpoint?
thank you!!!!
Hi there!
Your table is great and very detailed and you have included all the right scientists :)
In terms of how the development of their respective theories were influenced by society and politics, you could add these points to Darwin's theory:[li]1925: teacher from Tennessee arrested and put on trial for teaching the theory of evolution
- 1920's: Protestants campaigned against anti-biblical ideas of evolution
- Several US States: passed legislation which banned the teaching of evolution in public schools
[/li][/list]
In terms of answering a question on this dot point, I would do a paragraph for each of the three theories of evolution you have listed or a paragraph for each person (1. Lamarck 2. Darwin 3. Wallace). You would start of each by explaining the theories, their evidence and then the social and political influences.
Hope this helped! :)
Hello,
could you please explain me the difference between ADH and aldostrone and any tips and tricks to remember the two what they do and the differences. im a pro and confusing the two
Thank you!
Hello,
could you please explain me the difference between ADH and aldostrone and any tips and tricks to remember the two what they do and the differences. im a pro and confusing the two
Thank you!
Hi,
with pedigrees, what is a quick way to determine if the affected trait is dominant or recessive?
thank you! :)
thyroxine is secreted by the thyroid gland and controls metabolism (breakdown/build up of molecules)
does that mean the heat that is released is due to both the build up and breaking of molecules?
I was wondering when would thyroxine secretion be triggered? when there is a low body temperature? (to maintain homeostasis maybe?)
I am a bit confused about thyroxin being secreted in response to thyroid stimulating hormone. Is it because TSH stimulates the production and release of hormones from the thyroid gland and thyroxine is one of these hormones? Is thyoxine the only thyroid hormone? does it include parathyroid hormones?
I am quite confused about thyroxine and thyroid stimulating hormone. Help is greatly appreciated
Hello everybody
i was wondering if anyone knew any good sites or places to get past papers for half yearlies. my school doenst release any and i dont know where else to find them
thank you so much!
Hey guys,
Is a line of best fit curved or straight?? In what cases would you do that in comparison to joining the dots on a graph?
I remember I got marked up for drawing a straight line of best fit. I asked my teacher and she said that it should be a curve NOT a straight line, pretty much contradicts what I've learned for the past few years.
But I would ask your teacher to make sure. Did you get deducted marks or something?
Hey, I'm really confused with the difference between a pair of homologous chromosomes and chromatids?
hi im extremely confused about random segregation and homologous pairs and lining up all that stuff. could some one help me out please?
Hello!
In meiosis, random segregation basically describes that when homologous chromosomes separate and go into different gametes, you can't tell which chromosome ends up in which gamete (i.e. the allocation of chromosomes is random).
Homologous pairs are two chromosomes which have very similar sizes and the place where the centromere is on the chromosome is pretty much the same for both chromosomes. During prophase 1 of meiosis, they come together side by side (they align) and when metaphase 1 starts, these aligned pairs formed a straight line down the centre of the cell.
Hey, I'm really confused with the difference between a pair of homologous chromosomes and chromatids?Homologous Chromosomes are Maternal and Paternal versions of the same chromosome. That code for the same genes
Hi wondering what's the best way to determine if a condition is sexlinked dom/recessive/non sex linked Dom/recessive.
Thanks !
Hi guys,Antibiotics act on bacteria in various ways such as damaging the cell wall or disrupting functioning inside the cell. This is a pressure on the bacteria, this is the factor that determines which bacteria will live and reproduce or die; whether bacteria that has mutated to resit the damage or not.
I just have a question on antibiotic resistance and natural selection. Is the selection/ environmental pressure placed on the bacteria the antibiotic?
thanks :)
Hey! I'm just having a bit of trouble with this MAB dotpoint: Explain why the concentration of water in cells should be maintained within a narrow range for optimal function What are the main things that I need to know for this dotpoint?? Thankyouu
Hey! I'm just having a bit of trouble with this MAB dotpoint: Explain why the concentration of water in cells should be maintained within a narrow range for optimal function What are the main things that I need to know for this dotpoint?? Thankyouu
Hey! I'm just having a bit of trouble with this MAB dotpoint: Explain why the concentration of water in cells should be maintained within a narrow range for optimal function What are the main things that I need to know for this dotpoint?? Thankyouu
Hi
Is the peppered moth of the industrial revolution considered a modern example of natural selection ?
Thank u :)
Hi
Is the peppered moth of the industrial revolution considered a modern example of natural selection ?
Thank u :)
Hello, I have an assessed biology exam coming up for module 1 and 2, and I was wondering if anyone had any links to good past papers or exams that I can use to study from?? I really really need to do well in this exam, I'm good with content but I need to apply it as well.
Exam's in only a few days so any help is appreciated!!
Thanks so much :D
Hi, I'm just confused on how to answer this question from 'the search for better health)
Describe the importance of protein production for maintaining and repairing body tissue?
Thanks :)
Hello,
So I've a question on how exams are marked in Biology. So the marking guidelines, gives points in which students can include in there responses and also has standards for each range. Now, I said "can", does that mean that if we didn't include those specific points they suggested, would we be disadvantaged? Even if the points mentioned, were valid and correct.
For example,
The question is, "Explain the advantage adaptations of haemoglobin" 2 marks
Marking guidelines:
- 4 oxygen molecules per haemoglobin, Approx. 200 haemoglobin. Large quantity (1)
- Able to transfer gases and other products efficiently to cells. (1)
- Allows proper functioning and maintains pH as well. (1)
And let's say that the answer did not include "transfer gases efficiently" but instead wrote "transfer chemicals efficiently"... would they still get a mark?
To me, I think they should cause gases are chemicals ... lol. Or does marking responses requires SPECIFIC details, in order to earn marks...
I think for that example chemicals is a broad/vague term and if I saw it I'd think they don't know what haemoglobin is for, and are trying to write a vague term to hope for the best.
are grasslands, deserts examples of biomes or ecosystems?
Hey! How do I ace the 8 markers?? They encompass such a broad section of the syllabus and honestly they just intimidate me a lot ...
What are your best study tips for bio? Do you think it's best to start re-learning the content from now? There's about 2 months until trials!
What are your best study tips for bio? Do you think it's best to start re-learning the content from now? There's about 2 months until trials!
What are your best study tips for bio? Do you think it's best to start re-learning the content from now? There's about 2 months until trials!
Hey, I'm struggling with this question on my assignment;
Produce a table for both the disease and the microflora imbalance using the following headings:
- name
- pathogen
- cause
- symptoms
- treatment
What I'm understanding is that a microflora imbalance causes a disease, so then how do I answer this question?
Heyyss!
Currently we are doing Epidemiological studies right now but there is large confusion between the terms Morbidity and Prevalence.
Morbidity is the number of ill at a given time, and morality is the number of deaths but I don't understand because the definition for prevalence is number of cases at a given time.....So are they different or the same or do they even have correlation?
Confused,
Sweetpotato Farms :D
Heyyss!
Currently we are doing Epidemiological studies right now but there is large confusion between the terms Morbidity and Prevalence.
Morbidity is the number of ill at a given time, and morality is the number of deaths but I don't understand because the definition for prevalence is number of cases at a given time.....So are they different or the same or do they even have correlation?
Confused,
Sweetpotato Farms :D
Good question.
Mortality is pretty straightforward. It's the number of people who die over a given period. Mortality is an expression of the incidence of death (see above for definition of incidence).
Morbidity on the other hand is a little trickier, because it can be expressed as a prevalence or incidence. As above, prevalence is the number of people with a particular disease, whereas incidence is the number of new cases of the disease in a fixed time period.
I think you mean mortality? And what it means by number of cases given at a time means that say, in 2016 there were 17,000 people with lung cancer in Australia. That would be its prevalence. Incidence, I know isn't relevant, but just to hopefully create a clearer understanding, is the number of NEW cases. So of those 17,000 people, 2,000 were diagnosed in that year. Essentially prevalence: total at one time Incidence: Newly diagnosed.
Wait so what is the difference between morbidity and prevalence then?
Im so confused!!!
Also I'm realllyy sorry but I'm so slow at understanding this stuff O.o
Morbidity is just a fancy definition for illness. Prevalence is the number of illnesses. I know I didn't explain it very well. But does that make sense?
I've heard that some HSC markers may not read answers written below the given lines for section II of the paper. Is this true?? Also any tips on how to answer these short answer questions more concisely would be appreciated :) :)
Where did you hear that from? I can't see how it could be true. Even though marking a subject like biology would be a pain it is the markers job to mark. Maybe this is different, but for French I know, they mark everything written on your page. If it is true, I have massive writing and I'm a very wordy person so I'm screwed
Hi,
What is the pathogen that causes Giardiasis?
Thanks
help plssHi, sssona09!
2. How was the experiment of Miller and Urey important in illustrating the nature and practice of
science?
(A) Urey and Miller’s experiment was based upon several different hypothesises about the
origin of life.
(B) The experiments were designed so that other scientists could not replicate them.
(C) Urey and Miller’s experiments were designed to test one hypothesis about the origin of
life.
(D) Urey and Miller proved they could do an experiment that no one else wanted to do.
Is anyone able to help me in differentiating xylem and phloem? just like key points or any links to good diagrams? for some reason i have so much trouble with thisHi, leighshapiro!
Hi,
I am wondering when to use a line of best fit in biology, all the teachers tell something different.
On a practise exam the questions asks to graph the data from an experiment comparing pH to enzyme reaction rates. Obviously, the graph becomes almost like an upright triangle, so it isn't linear.
So, do you do a line of best fit here, or connect the dots?
For pH vs enzyme activity it should be 1/clotting time vs pH which would be a bell curve, so either join the dots or do a curve of best fit! Make sure you label it 'line of best fit' or 'curve of best fit'. Usually do a line or curve of best fit if you EXPECT a perfect line or curve but some points are a bit off.
Hey, I'm struggling with this question on my assignment;
Produce a table for both the disease and the microflora imbalance using the following headings:
- name
- pathogen
- cause
- symptoms
- treatment
What I'm understanding is that a microflora imbalance causes a disease, so then how do I answer this question?
Hi can anyone answer this biology question i found in a trial. Describe the historical role that models played in determining the structure of DNA as the 'chemical of life'. (4 MARKS). Not sure where to start....
Hi,
I am wondering when to use a line of best fit in biology, all the teachers tell something different.
On a practise exam the questions asks to graph the data from an experiment comparing pH to enzyme reaction rates. Obviously, the graph becomes almost like an upright triangle, so it isn't linear.
So, do you do a line of best fit here, or connect the dots?
For anyone doing the option Genetics Code Broken could you explain the outcome: identify the role of genes in embryonic development. I'm finding it really difficult to understand
Hi all, just wondering if there's a quick way to draw tables?
I often hear suggestions to answer compare questions with a table, but I feel like it takes me too long to rule out a table that's neat enough to justify the amount of time it takes. Are there any ways I can cut corners?
Hi! Can I please have some help with this question?:
Some people believe that transgenic organisms may play a large part in food production in the future.
Describe the genetic make-up of ONE transgenic organism you have studied. 1m
It's probably straightforward but I don't understand what it means by 'genetic make-up'
Thank you in advance :)
Hi orl1999!
An example of a transgenic organism which would be great for this question would be BT Wheat. This is a genetically modified wheat crop which has a bacterium gene (from the Bacillus thuringiensis) encoding a toxin inserted into its genome. This makes it naturally resistant to pests, so that farmers don't need to use pesticides/insecticides.
Basically when the question asks for 'genetic make-up', it's just asking what genes are added, encoding what specific characteristics.
Help!
There was a particular question in my Biology test paper that was marked down. The question was: 'Link the structure and function of a feature of the mammalian eye'.
My answer was this: 'The choroid is a layer of the eye that consists of blood vessels near the outer surface of the layer. The blood vessels transports oxygenated blood around to the choroid layer which maintains the functioning of the eye as the eye requires cellular respiration and thus the need for oxygen to carry out the functioning of the eye'.
The feedback was simply that it did not link the structure to the function... but I'm not convinced since I did state the feature ('choroid') with its function ('blood vessels near the outer surface layer') and the function ('transports oxygenated blood to mantain functioning of eye')?
Would like to know your opinion on this, please!
Thank you!
Help!
There was a particular question in my Biology test paper that was marked down. The question was: 'Link the structure and function of a feature of the mammalian eye'.
My answer was this: 'The choroid is a layer of the eye that consists of blood vessels near the outer surface of the layer. The blood vessels transports oxygenated blood around to the choroid layer which maintains the functioning of the eye as the eye requires cellular respiration and thus the need for oxygen to carry out the functioning of the eye'.
The feedback was simply that it did not link the structure to the function... but I'm not convinced since I did state the feature ('choroid') with its function ('blood vessels near the outer surface layer') and the function ('transports oxygenated blood to mantain functioning of eye')?
Would like to know your opinion on this, please!
Thank you!
Holla,
For the dot point:
Process information from secondary sources to describe and analyse the relatively importance of the work of:
James Watson
Francis Crick
Rosalind Franklin
Maurice Wilkins
in determining the structure of DNA and the impact of the quality of collaboration and communication on their scientific research
What sort of information are we to learn under this dotpoint? Because in my midyears I received a 3 out of 7 for the question in regards to this dotpoint and the marking said that I didn't specify their collaboration well enough...However i did actually mention how the collaboration was bad leading to the success of Rosalind and Wilkins being jeopardised and how good collaboration between Watson and Crick eventually got them the Nobel Peace Prize.
Any suggestions?
Bigsweetpotato Farm
Holla,
For the dot point:
Process information from secondary sources to describe and analyse the relatively importance of the work of:
James Watson
Francis Crick
Rosalind Franklin
Maurice Wilkins
in determining the structure of DNA and the impact of the quality of collaboration and communication on their scientific research
What sort of information are we to learn under this dotpoint? Because in my midyears I received a 3 out of 7 for the question in regards to this dotpoint and the marking said that I didn't specify their collaboration well enough...However i did actually mention how the collaboration was bad leading to the success of Rosalind and Wilkins being jeopardised and how good collaboration between Watson and Crick eventually got them the Nobel Peace Prize.
Any suggestions?
Bigsweetpotato Farm
The collaboration between Rosalind and Wilkins was ineffective, which meant their work was not efficiently researched and they had a lack of communication. This lack of effective communication led to Wilkins leaking Rosalind's research from x-ray crystallography to Watson and Crick. Because Watson and Crick had great communication, they worked well and communicated well. This meant that even though they were told to stop after they failed numerous times, they continued to persevere and work together to produce the current model of DNA.
Hi Bigsweetpotato2000,
Just adding to the great points pikachu975 made, another important thing that Watson and Crick did in terms of collaboration was that they built upon other people's ideas. They took information from other scientists (Chargaff's rules of nitrogen pairing, and Franklin's 'photograph 51'), and synthesised them in a creative way, collaborating to come to a solution. This enables more effective scientific practice, and evidently betters the scientific community when people are working together.
Hope this helps!
Hey!
I'm a little unsure about how to answer this question, any help is muchly appreciated!:
'The Black Plague was an infectious disease devastating Europe between the 14th and 19th centuries. The disease was caused by the bacteria Yersinia pestis
Yersinia pestis usually infects the intestines, but during the Black Plague it infected the lungs, causing pneumonia-like symptoms and killing millions of people.
Recently published research on the bacteria indicates that a small genetic change in the bacteria as far back as 2500 years ago may have caused it to go from a treatable infection of the intestines to a fatal lung infection.
Using your knowledge of Darwin's Theory of Natural Selection, explain how Yersinia pestis may have changed from being an intestinal infection to become a much more severe lung infection.' 3marks
Thank you!
What's microflora in humans? - Search for a better health section :D
Bigsweetpotato Farm
Hi Bigsweetpotato2000,
Microflora simply refers to all the naturally occurring micro-organisms that cover/are in our bodies. This can be bacteria, fungi, all different types of microorganisms. Microflora is important for human health (there have been recent studies linking healthy gut bacteria and mental health), but can cause disease when the balance of microorganisms is disrupted (for example, thrush, when Candida albicans is allowed to grow in excess).
Ahhhh... So how does Thrush develop from the imbalance? I think I was to use that as my example but I can't find it in my notes....
Thanks!
Bigsweetpotato Farm
Basically when you take antibiotics, it gets rid not only of bad bacteria but some of the good bacteria as well. Our natural microflora has the right balance of different microorganisms, growing at consistent rates, kind of keeping each others populations in check. So when one of the microorganisms is removed, the other is able to grow more, because of less competition and more resources. For thrush, the fungi Candida albicans will grow in excess (as it is not killed by antibiotics), generating symptoms as it becomes an irritant.
Hope that makes sense
Oooh I'll give it a try :D
First Up! Define Evolution
Charles Darwin in the 19th century proposed the Theory of Evolution by natural selection as a process in which organisms change over time as a result of new environments, allowing the organism to better adapt to its new habitat.
2nd - Relate the case study to the three aspects of evolution: Variation, Heritability and Over Reproduction.
The Yersinia pestis's evolution from a intestinal infection to a more severe lung infection was potentially due to the variations in the population that survived the treatment 2500 years ago. The certain bacteria with a random genetic difference survived the treatment provided during the contemporary time and continued to survive, slowly reproducing over time to increase the chance of the new species survival. This resulted in the evolution of the Yersinia pestis, which became a more severe lung infection.
Hope that works :D
Bigsweetpotato Farm
Oooh I'll give it a try :D
First Up! Define Evolution
Charles Darwin in the 19th century proposed the Theory of Evolution by natural selection as a process in which organisms change over time as a result of new environments, allowing the organism to better adapt to its new habitat.
2nd - Relate the case study to the three aspects of evolution: Variation, Heritability and Over Reproduction.
The Yersinia pestis's evolution from a intestinal infection to a more severe lung infection was potentially due to the variations in the population that survived the treatment 2500 years ago. The certain bacteria with a random genetic difference survived the treatment provided during the contemporary time and continued to survive, slowly reproducing over time to increase the chance of the new species survival. This resulted in the evolution of the Yersinia pestis, which became a more severe lung infection.
Hope that works :D
Bigsweetpotato Farm
This is a good start, and I particularly like how you've broken down the question. You might consider the potential survival advantage of transitioning to a respiratory infection for Y.pestis.
The question specifically asks about Darwinian evolution, which actually rests on four principles:
1. Heritability of traits
2. Variation in the population
3. Limited resources therefore struggle for existence
4. Some better adapted than others
HAHHA Whooooops
I knew my answer was lacking something - Thanks!
Going to change my notes now
However, isn't over reproduction in the evolution theory? Since reproduction is required in order to increase the chance of the evolved species survival?
can anybody clarify what EPOCH means. This is relating to an assessment on 'Life on Earth', for which I have to create an accurate geological timeline.
can anybody clarify what EPOCH means. This is relating to an assessment on 'Life on Earth', for which I have to create an accurate geological timeline.
This is part of the preliminary course right? It rings a bell but can't quite recall what it is.Yes this is the prelim course. If you are looking for the definition, its particular period of time marked by distinctive events, which makes sense with the life on earth topic.
Really good question :)
It's captured under the limited resources heading. Resources can be limited by lowering the amount of resources OR by producing too many things trying to use all of those resources. In simpler terms, a big population (over-reproduction) makes the resources limited.
I've stayed on top of my syllabus summaries all throughout year 12 and I'm wondering about any quick and easy way to remind myself of the content for namely MAB and BOL... thanks!
What are your best study tips for bio? Do you think it's best to start re-learning the content from now? There's about 2 months until trials!
Hey guys, is it necessary to know the steps of deamination? Or just the gist of it?
So for the HSC do we still need to know premlim topics such as protein synthesis in detail
Hi Daniyahasan,
You definitely need to understand how polypeptides are formed by transcription and translation, and then understand that polypeptides are folded into proteins. If you need a brief overview of what steps are essential, and what enzymes you need to know, I've got an overview in the powerpoint slides I presented for lectures here!
Hey can someone please help me with this ? What is the type of inheritance shown ? I can't differentiate between dominant and recessive inheritance by looking at the pedigree, please help.
Hey can someone please help me with this ? What is the type of inheritance shown ? I can't differentiate between dominant and recessive inheritance by looking at the pedigree, please help.
this question is really confusing me, can someone please explain it to me
Im pretty sure the answer is B because the lower the pH the higher the acidity :)makes sense, thank you!
one more questionohh i love these types of questions haha
I dont remember doing this in class, so im really confused to as what i should be doing for this question
TBH this looks like a bs questions. Codons are in triplets therefore id guess uua, ccg and acu were the three pairs. so for uua, look at the first base axes, find u and do the same for the other two axes. it's probs c)
Hey guys, can somone pls help me with this question
Hi!
When a stimulus is introduced, a receptor (A) detects the change, which is then passed along a sensory neuron (X) to the CNS. After the brain receives and interprets the information, it passes down a signal along a motor neuron (B) to the effector muscle/gland, which then carries out the response.
Therefore, the answer would be C: A = receptor, B = motor neuron.
Hope this helps!
what are gametestheyre sex cells
Hello, just a short question, when giving your answers, could you explain why the others are incorrect please?The answer would be A. This is because the wale lives in a salty environment and is constanly losing water via osmosis, so it needs to excrete concentrated urine in order to maintain water levels.
Thanks
The answer would be A. This is because the wale lives in a salty environment and is constanly losing water via osmosis, so it needs to excrete concentrated urine in order to maintain water levels.
B is incorrect as whales excrete salt rather than store it as they need to get it out of their system.
C is incorrect since whales excret small amounts of very concentrated urine to preserve water, where as humans excrete urine that is still concentrated but just a little more dilute depending on environment and water intake.
D. Is correct in a way but it wouldn't be the answer to this question. The reason why the humans need to excrete more to remove the same amount of salt comes down to the concentration rather than the amount. Since whale urine is saltier it will take less urine to excrete the same level of salt as the human which has more dilute urine and needs to excrete more.
Hope this makes sense! (I know what I mean but not sure if I have articulated it well)
Hey! Thanks for the answer, I also put A, but the answers say it is D.
I thought I must have missed something.
Thank you for the clearup :)
Can someone please explain to me the concept of sex-linkage?? I understand it, but when given a question always mess it up thxxx
Where's the question from? My suspicion is that they've just stuffed up and that A is correct.
Hey, GuysExons are the coding regions of DNA. That is, they encode proteins and express genes.
can someone please explain to me what introns and exons are??
thanks
Hey! I'm struggling to answer the higher order questions like the 7 marker questions!!! Like when I go to the marking guideline, I didn't even think of including some of the things that must've been incorporated in our response to gain the marks.The key section is its directive term, justify
For example, in the attachment, I wouldn't even think of writing about the problems engaged initially...
The key section is its directive term, justify
It's a good idea to get used to what BOSTES wants with these directive terms.
So, to justify something means to support an argument or conclusion.
My personal marking breakdown:
1 mark -- Define DNA-DNA hybridisation.
1 mark -- Define karyotype analysis
2 marks -- Outline the uses of DNA-DNA hybridisation
2 marks -- Outline the uses of karyotype analysis
1 mark -- Relate these uses back to the stimulus (ie how are they used to solve these problems)
The breaking down of marks just comes back to practice and practice!!
The more you understand what they want, the better you'll be at it.
Hey guys, how do you go about answering the "How would you improve this experiment?" questions?
most important (or most commonly asked) concepts to nail down in bio core? I have two days to prepare #ragrets :-[ :-[ :-[
most important (or most commonly asked) concepts to nail down in bio core? I have two days to prepare #ragrets :-[ :-[ :-[
Hi! imo there is a lot of things that could be asked, here is my suggested list:
Blueprint of Life
- Natural selection + Theories of evolution
- Transcription + Translation
- Transgenic species
- Scientists: Mendel (peas), Morgan (fly), Beadle/Tatum (one gene-one polypeptide), Watson/Crick/Franklin/Wilkins (DNA structure)
Maintaining a Balance
- Enzymes (essentially the entire topic evolves around them)
- Xylem/phloem mechanisms, technologies for O2 saturation/CO2 concentration
- Artificial blood (progress + reasons why it's needed)
- Kidney (Aldosterone/ADH, what substance is absorbed [and where it's absorbed on the nephron], hormone replacement therapy, dialysis)
- Different types of nitrogenous wastes and which insect mammal uses which (ammonia/urea/uric acid)
Search for Better Health
- Practices assisting in disease control
- Difference b/n types of pathogens
- Description of infectious disease (name, cause, transmission, symptoms, host response etc.)
- Defence barriers and adaptations
- Scientists: Pasteur (swan v straight-neck), Koch (particular micro-org. to particular disease)
(Haven't finished SBH yet so not sure about the rest)
Hope this helps! Use these 2 days for past-papers, they're a more effective way to learn than just highlighting your notes imo :)
bless you!! I will definitely. I'm hoping my excellent winging skills will pull thru this time D: But do you think I should do HSC past papers or trial past papers?
bless you!! I will definitely. I'm hoping my excellent winging skills will pull thru this time D: But do you think I should do HSC past papers or trial past papers?
Hi i'm doing communication and i was wondering that even though light is directed by the lens onto the retina, is it always trying to principally direct it onto the fovea even it was dark?
Thanks! :)
Memorise the content first if you don't know it. You can't rely on winging skills in biology you get marked down if you don't have specific terminology or sufficient detail.
There's a dotpoint in SFBH - Outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health
I'm getting confused about the difference between cell specialisation and differentiation and how both actually assist in the maintenance of health
There's a dotpoint in SFBH - Outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of healthHi, sidzeman!
I'm getting confused about the difference between cell specialisation and differentiation and how both actually assist in the maintenance of health
Thanks!
Also, could you please explain the difference between Boveri's and Sutton's work - it seems to me like they did the same thing, but Sutton just took it further and linked chromosomal division to Mendel's traits
Hi!
Walter Sutton : Studied meiosis in grasshoppers, noted similarities between chromosomal behaviour and laws of segregation/independent assortment
- Segregation: During meiosis, each gamete cell receives one chromosome of each pair
- Independent Assortment: Chromosomes arrange themselves independently along the middle of the cell just before it divides
- Genes would segregate independently if they were on different homologous chromosomes
- Suggested that not all characteristics followed Mendel’s law of independent assortment
- Several Mendelian factors are present in 1 chromosome, could be inherited as a unit
- Concluded that chromosomes were carriers of hereditary information
Theodore Boveri: Experimented with sea urchins, provided evidence for the halving of chromosome numbers during the process of meiosis and that a definite set of chromosomes is required to produce normal development
- Zygote chromosomes: 50% egg, 50% sperm
- If the nucleus of only one parent was present, the larvae resembled that parent, but with some abnormalities
- When a normal egg and sperm fused, the resulting offspring showed characteristics of both parents
Hope this helps :)
Ohhhh so Boveri didn't link chromosomes to carriers of inheritance - he only observed offspring get one from each parent? I had it written down as part of Boveri's work
Also how did Sutton infer that not all characteristics followed Mendel's law of independent assortment?
Hey!Hi, bigweetpotato2000!
Can someone explain this question to me why it's answer B?
Thanks
Hi, bigweetpotato2000!
When we're exposed to changes within the ambient environment, our body attempts to maintain constant homeostasis (important to note from MAB). Thus, blood circulation (vasodilation and vasoconstriction) become the essential elements to homeostasis. In penguins, they are no different.
When penguins are exposed to the cold air, their core body attempts to maintain that level of constant stability, meaning that vasoconstriction is taking place outside of that core body (ie there will be less blood flow to the extremes, such as hands and feet).
Conversely, when penguins are exposed to the hot air, their core body will still attempt to maintain that level of homeostasis, which means there will be a rush of blood flow towards the extremities (vasodilation).
Biological Familia,
Would Question 14, would it be C or D
C could be a potential answer if the heart suddenly gets rejected a long time after operation then the person dies pretty damn quickly?
D is the normal answer if the immune system is weak after the antibiotics right?
Bigsweetpotato Farm
Hello!
Your answer for C is absolutely correct! If these suppressor drugs weren't used, the body will continue to attack the patient!
D is wrong because Anti-biotics aren't needed until a disease is present. Suppressor drugs do lower immune defence, but it does not mean that there is a constant threat of an infectious disease. Also, most antibiotics are specific to certain bacteria, so applying before any symptoms is a very bad idea. Also, this constant use will cause an imbalance of microflora in the body and can cause thrush. ALSO ALSO, the constant feed of antibiotics is a bad idea due to natural selection, where the constant intake of antibiotics can cause a strain of bacteria to be resistant.
So for the best answer, I would go C
Hope this helps :)
Biological Familia,It'd be wise to note what immunosuppressive drugs actually do to prevent rejection of organ transplant.
Would Question 14, would it be C or D
C could be a potential answer if the heart suddenly gets rejected a long time after operation then the person dies pretty damn quickly?
D is the normal answer if the immune system is weak after the antibiotics right?
Bigsweetpotato Farm
Hey, can someone please explain Mitosis to me?
Hey,divergent evolution is where there is a single common ancestor where differences in the population arise due to chance, no gene flow between populations. As a result a new speices is formed.
What is the difference between Divergetn and convergent evolution?
Hey,
What is the difference between Divergetn and convergent evolution?
Hi :)
Just adding onto the above answer with examples:- Analogous structure: Streamlined shape and fins
- Convergent Evolution: Dolphins (Mammals) and Sharks (Fish)
- Purpose: Propulsion and stability for movement in a viscous environment- Homologous structure: Five digit limb
- Divergent Evolution: Pentadactyl limb (Mammals)
- The limb is found on humans/cats/bats/whales, but perform different functions depending on their environment
Hope this helps ;D
Are you sure that sharks and dolphins' body types are an example of convergent evolution? The earliest mammals developed in the ocean as I understand it, therefore they probably started off with a structure that they inherited from fish. They subsequently diverged.
Analogous structures imply that they both independently evolved the same thing, but I'm not sure that's the case?
Hi :)
From what I have been taught in class and a browse through Google to make sure, dolphins evolved from land-based animals :)
Hi! In Communication, will we ever have to draw the structure of an entire eye?
Hi!
I've seen past questions on this before (attached image from 2009 HSC)
(http://i.imgur.com/wCDzRUz.png)
Even if it may not be asked, it helps in memorising the relationship between the different structures of the eye and their functions.
Hope this helps!
Hi! In Communication, will we ever have to draw the structure of an entire eye?
Hey guysIt's a six marker, so it requires you to have an extensive knowledge behind the reproductive techniques and genetic diversity. So, to help us break down the six marks, we need to locate appropriate and relevant information and then break these information down into its components.
Can someone pls explain how I would structure my answer for this question
Thanks
1. Which of the following was present in abundance when organic molecules first developed on earth?
a) Bacteria
b) Oxygen
c) Glucose
d) Water
thank youuu
Hi!thank you!! :)
Not A: Bacteria were formed after organic molecules first developed (first appeared 2.5bya e.g. cyanobacteria)
Not B: There was a lack of O2 in the early earth, only volcanic gases were present
Not C: No organisms were present to produce glucose as a source of energy
Therefore, the answer is D.
Hope this helps
heeey :) help pls
Hi,
Not 100% sure, but I think the answer is C:
- Autotrophs make their own food by converting inorganic molecules to organic compounds (e.g. through photosynthesis)
- Heterotrophs have to consume autotrophs to produce energy, and they respire (which provides CO2 for the autotrophs)
Hope this helps
For ectotherms and endotherms how do their metabolism AND enzyme rates differ at different temperatures?
Use your understanding of genetics and evolution to explain why some charcteristics becomes more common in a population than others please help
Could someone please help me with how to best answer this question??
Compare the way mammals transport oxygen and carbon dioxide in the blood. (4 MARKS)
Mammalian blood transports oxygen and carbon dioxide between the lungs and other tissues throughout the body.Good introductory sentence :) These gases are carried in various forms such as dissolved in the plasma or chemically combined with haemoglobin. For oxygen transport, oxygen binds with haemoglobin in the lungs, where the oxygen concentration in the blood is low, and transports it to where the oxygen is needed. Once it reaches the desired location the oxygen bond easily breaks and the oxygen is used for processes such a respiration Not entirely sure about the relevance of this sentence to the question. However, for carbon dioxide transport it is carried in the blood in in two forms; dissolved in plasma and travels as bicarbonate ions resulting from the dissociation of carbonic acid.You've talked about the similarities and differences between these two gases, which directly addresses the question :)
Endotherm
At a low temp,At a normal temp,
- Metabolism increases to maintain body temp and function
Enzyme rates stay contstant due to a regulated internal environment- homeostasis. However, extreme temps will result in denaturing (obv)At a high temp,
- Metabolism is normal
Enzyme rate is normal
- Metabolism is higher once again as body needs to work harder to maintain homeostasis
Enzyme rate stays constant due to homeostasis. However, extreme temps will result in denaturing (once again obv)
Ectotherm
At a low temp,At a normal temp,
- metabolism is low cos unable to do shit
Enzyme rate is low cos of dependency on ext temp for function. will result in denaturing if extreme tempsAt a high temp,
- metabolism is normal
enzyme rate is normal
- Metablosim is way higher as activity correlates with temperature increase
Enzyme rate is higher till peak is reached followed by drops and eventual denaturing.
you could have just thought about it...
Could someone please help me with how to best answer this question??Hey!
Compare the way mammals transport oxygen and carbon dioxide in the blood. (4 MARKS)
This is my answer but I'm worried I'm missing things:
Mammalian blood transports oxygen and carbon dioxide between the lungs and other tissues throughout the body.These gases are carried in various forms such as dissolved in the plasma or chemically combined with haemoglobin. For oxygen transport, oxygen binds with haemoglobin in the lungs, where the oxygen concentration in the blood is low, and transports it to where the oxygen is needed. Once it reaches the desired location the oxygen bond easily breaks and the oxygen is used for processes such a respiration. However, for carbon dioxide transport it is carried in the blood in in two forms; dissolved in plasma and travels as bicarbonate ions resulting from the dissociation of carbonic acid.
Hi I've really struggled with graphs like no matter how hard I try I always seem to stuff them up (maths has never been my strong point). I just wanted to clarify a few things bc I've gotten different responses from different teachers about certain things. Firstly I don't understand when you are supposed to join the dots or draw a line of best fit (I lost a mark in trials for drawing a LOBF). Also I get confused over whether you are supposed to connect the first dot to 0 or not ? Thirdly, I find I always have doubt over whether to use a bar or line graph and I always end up picking the wrong one, I understand that line is usually continuous data and discrete for bar (I think), but I still get confused about it all like in one of my exams they wanted a bar graph for an experiment involving time?? Anyway, some clarification would be super helpful as the graph in trials seriously stuffed up the majority of my exam after I did the entire thing wrong after spending 15 mins on it and had to start all over again (leaving me with 5 mins to do the 7 marker which was not ideal haha).
Use your understanding of genetics and evolution to explain why some characteristics become more common in a population than others please help
Use your understanding of genetics and evolution to explain why some charcteristics becomes more common in a population than others please help-genetic variation exists in a population
Hi, I'm still finding it so confusing to differentiate between prevention and control. Different sites say different things... I was hoping to clear it all up. Do you have any suggestions as to how to remember the difference?Hey there!
can someone please explain how renal dialysis worksHey there!
i find it a difficult concept to grasp on
hey i was wondering how having thick bark and sunken stomata reduces water loss in plants? THanks :DSunken stomata creates an area where water leaving the leaf can pool, keeping water in the leaf longer and decreasing the rate of transpiration, an example being the casuarina. Sorry, I don't have anything about thick bark in my notes, but from a quick google it seems thick bark is for fire prevention or something, e.g. during a fire the outer layer burns off protecting the cells inside. I'm not entirely sure though
Sunken stomata creates an area where water leaving the leaf can pool, keeping water in the leaf longer and decreasing the rate of transpiration, an example being the casuarina. Sorry, I don't have anything about thick bark in my notes, but from a quick google it seems thick bark is for fire prevention or something, e.g. during a fire the outer layer burns off protecting the cells inside. I'm not entirely sure though
Hey there!Oh wow thanks soo muchh
Renal dialysis is the artificial process of removing excess water and waste from the blood. It acts as a replacement to faulty kidneys, since people with faulty kidneys cannot perform the necessary actions needed to remove these excess water and waste. As a result, the use of renal dialysis is extremely important to this process.
Before understanding why this process is important, however, we need to consider how important of a role a kidney plays in our everyday lives. As we consume increased volumes of water, the role of the kidney is to "balance" out the mineral ions of potassium, calcium, sodium, and many more and maintain its equilibrium point. The acidic waste products are excreted by the kidneys. So, it is in your best interest to have functioning kidneys. Else, the internal pH of the blood decreases, leading to a denaturation of enzymes (remember that enzymes work at narrow pH levels).
In the case of kidney failures then, we need to develop some artificial process that works the same way a regular kidney does. This is known as renal dialysis. This works by diffusing solutes across a semi-permeable membrane. As a result, smaller solutes are able to pass through, leaving the larger solutes unfiltered (much like the glomerulus and Bowman's Capsule).
There are two types of dialysis:
Hemodialysis works by removing excess water and waste by circulating the blood from an external filter. This is called a dialyser, and it contains the semi-permeable membrane. As a result, the blood flow is one directional.
Peritoneal dialysis work by removing excess water and waste from the blood internally. The peritoneum acts as the semi-permeable membrane, and the waste is moved from the blood across the peritoneum into a dialysate.
can someone please explain action potential and threshold i do not understand that at all
hey,hscninja.com used to have a consolidated quiz mode where you could select a topic and they'd pick past questions for you to do. unfortunately bostes made them take it down because copyright, but they still have past questions sorted by topic. If you want, you can buy the success one HSC biology book which has the 2001-2005 sorted by topic rather than by paper
does anyone know any websites that has topic tests for search for better health?
can someone please explain action potential and threshold i do not understand that at all
Hey for Communication, I didn't really understand what it means by rods having high retinal convergence causing them to have poor visual clarity. Thanks :)Rod cells are found in bunches of thousands and are attached to a single nerve cell, resulting in high retinal convergence, consequently also resulting in poorer vision acuity. This coupled with the ability of rod cells to only distinguish between dark and light results in them to have poor visual acuity. In contrast, cone cells are each attached to a single nerve cell which coupled with their ability to distinguish colour results in them having higher visual acuity.
Rod cells are found in bunches of thousands and are attached to a single nerve cell, resulting in high retinal convergence, consequently also resulting in poorer vision acuity. This coupled with the ability of rod cells to only distinguish between dark and light results in them to have poor visual acuity. In contrast, cone cells are each attached to a single nerve cell which coupled with their ability to distinguish colour results in them having higher visual acuity.thanks!
1) Resting membrane potential of -70 mV.
2) A stimulus occurs which causes depolarisation if the threshold of -55 mV is met, i.e. voltage-gated sodium ion channels open so sodium ions rush in the axon which causes membrane potential to change to around +40 mV.
3) Repolarisation occurs where sodium ion channels close and potassium ion channels open, causing potassium to rush out. This makes the membrane potential down to -75 mV.
4) Since it is too negative, repolarisation occurs which means that all ion channels close and the sodium-potassium pump balances the membrane potential to -70 mV, also known as the refractory period.
Hey,Memorising is KEY. if you have your notes memorised, then when you respond to questions, the syllabus metalanguage with flow automactically, but you need to have written with that kind of language in the first place :)
I'm not doing that great in biology. My main concerns are that I don't include the exact word or two that the teachers are looking for, and am not very concise. Any ways to help with this?
Hi, can someone please summarise the following communication dot points for me? I am super confused as all the information in the textbooks and other notes I've seen is super convoluted :(
-> identify those areas of the cerebrum involved in the perception and interpretation of light and sound
->perform a first-hand investigation to examine an appropriate mammalian brain or model of a human brain to gather information to distinguish the cerebrum, cerebellum and medulla oblongata and locate the regions involved in speech, sight and sound perception
Hi!
- Light/Sight (Occipital Lobe)
- Visual cortex: Where signals are sent from the retina via the optic nerve to the brain
- Visual association area: Processes and interprets visual information)
- Sound (Temporal Lobe)
- Auditory area: Where signals are sent from the hair cells in the organ of Corti via the auditory nerve to the brain
- Auditory association area: Processes and interprets auditory information
- Speech:
- Wernicke's Area: Sensory speech
- Broca's Area: Motor speech
(https://i.imgur.com/r8KXYVE.png)
Hope this helps
Memorising is KEY. if you have your notes memorised, then when you respond to questions, the syllabus metalanguage with flow automactically, but you need to have written with that kind of language in the first place :)
Is there like a good guide for writing with the syllabus meta language? Like any example study notes?
Atarnotes has a bunch of free notes you can download or if you want the BEST notes you can buy the Atarnotes biology notes for $25
trust me you need those notes in your life:)
(i should be paid for the amount of promotion i do for Atarnotes lolll, i literelly tell everyone)
Hey guys! So for anyone doing the communications elective, do we have to know how to modulate sound waves? :-[
Thanks!
Hey guys! So for anyone doing the communications elective, do we have to know how to modulate sound waves? :-[
Thanks!
Hi,
So I just have a quick question for action potentials in communication,
Do the sodium channels open as soon as stimulus is detected to begin depolarisation? Also, is it ok to say -50mv for the threshold p, not -55,v?
Hi,
So I just have a quick question for action potentials in communication,
Do the sodium channels open as soon as stimulus is detected to begin depolarisation? Also, is it ok to say -50mv for the threshold p, not -55,v?
Yep stimulus opens voltage-gated sodium ion channels which causes them to rush in. However, if the stimulus is too weak it doesn't open enough so it doesn't depolarise enough to reach an action potential.
Threshold is anywhere between -50 and -60 mV but best to use -55 mV.
Hey, Guys
Does anyone understand what refraction of light has to do with myopia and hyperopia
Hey, Guysmyopia (short sightedness) – close objects can be seen clearly but distant objects (more than about 5 meters away) appear blurred and out of focus
Does anyone understand what refraction of light has to do with myopia and hyperopia
Hi, the biology syllabus printed for us by our teacher has extra parts to the syllabus that I can't seem to find any notes on and a lot of people just seem to ignore, so I'm a bit confused by this. What I can't find is
- Outline the role of rhodopsin in rods and cones
- describe rods as containing a form of rhodopsin that is sensitive to blue green light
Hi, the biology syllabus printed for us by our teacher has extra parts to the syllabus that I can't seem to find any notes on and a lot of people just seem to ignore, so I'm a bit confused by this. What I can't find isi just looked at the syllabus and i agree i dont really see those dotpoints (iv linked the syllabus below if you wanna look again)
- Outline the role of rhodopsin in rods and cones
- describe rods as containing a form of rhodopsin that is sensitive to blue green light
Hi!
- Cones don't contain rhodopsin; they contain iodopsin. They are the type of photoreceptor cells that are sensitive to colour
- Blue = 455 nm (Short wavelength)
- Green = 530nm (Medium wavelength)
- Red = 625 (Long wavelength)
- Wavelengths either side of these values can stimulate more than one Iodopsin type to create secondary colours (Magenta: Blue/Red, Cyan: Green/Blue, Yellow: Red, Green)
- The brain can perceive colours and shades depending on the number and combination of iodopsins stimulated
Hope this helps
why is their school giving them a dotpoint to study if it isnt even correct......?Maybe it's an old syllabus and hence why that part has been taken out (because it's supposedly incorrect), cause knowing my school it wouldn't have been on purpose, my teacher has been teaching for aggggeees (at this point he looks like Santa Claus) and probably gave us the old one by mistake
Maybe it's an old syllabus and hence why that part has been taken out (because it's supposedly incorrect), cause knowing my school it wouldn't have been on purpose, my teacher has been teaching for aggggeees (at this point he looks like Santa Claus) and probably gave us the old one by mistake
Maybe it's an old syllabus and hence why that part has been taken out (because it's supposedly incorrect), cause knowing my school it wouldn't have been on purpose, my teacher has been teaching for aggggeees (at this point he looks like Santa Claus) and probably gave us the old one by mistakeoh yeah probably! luckily you asked so thats cleared up for you know. My maths teacher is like that to HAHAHAHA, shes been teaching for 40 years damn
Could anyone offer a summary of the different types of bio options? Our school usually does communication but our teacher is willing to change it seeing as it's the final year and he really likes the genetics option (which he said was like an extension of the things we did in year 10, like dihybrid). Which topics are more conceptual and which ones are more equation-y?
Hi! I'm super confused about a Communication dotpoint because I'm receive 2 different answers. In the textbook it says that when detecting yellow light the blue and green cones are responding, however, websites and pictures depict red and green cones responding to interpret yellow. Which is correct?
Hi!
- Light/Sight (Occipital Lobe)
- Visual cortex: Where signals are sent from the retina via the optic nerve to the brain
- Visual association area: Processes and interprets visual information)
- Sound (Temporal Lobe)
- Auditory area: Where signals are sent from the hair cells in the organ of Corti via the auditory nerve to the brain
- Auditory association area: Processes and interprets auditory information
- Speech:
- Wernicke's Area: Sensory speech
- Broca's Area: Motor speech
(https://i.imgur.com/r8KXYVE.png)
Hope this helps
Hi, could someone please mark and give me feedback on this question?
Q: "Gregor Mendel revealed the world of genetics to future biologists". Using your knowledge of the HSC Biology course, discuss the contribution of Mendel in relation to the development of our understanding of inheritance and modern genetics". (7 marks)
Mendel's investigations using pea plants have grown our understanding of genetics, contributing to future developments. In his experiment, Mendel first established pure breeding lines of tall and short pea plants. He then cross bred the tall and short and recorded the height of the plants. He had found that they were all tall. Again, he crossbred the offspring of the first generation and found that 75% of the offspring were tall, while 25% were short. From this, Mendel inferred that individual held two variants ( now called alleles) of a characteristic (now called a gene), and that each allele was provided by each parent.
In addition, he also established that certain alleles were dominant over others. This means that if at least one dominant allele was present in a genotype, it would be reflected in the phenotype. Recessive genes on the other hand, mean that both alleles need to be present in the genotype for it to be expressed in the phenotype. This dominance was demonstrated through the tall plants in Mendel's experiments, for both Tt and TT plants were tall, hence tall is dominant, while recessive alleles were shown through the short plants (tt), hence short is recessive.
Importantly, Mendel's work on alleles and dominance in inheritance has led to new developments. Firstly, Sutton and Boveri's work on sea urchins and grasshoppers elaborated upon Mendel's ideas, suggesting that chromosomes were the carriers of hereditary information, or as described by Mendel, "characteristics". Furthermore, more work into alleles has revealed different types of dominance. For example, Morgan's work on fruit flies, demonstrated "sex-linked" traits, where certain traits were more dominant depending on sex, such as if they only appeared on the X chromosome. Also, later work also revealed more complex forms of dominance such as co-dominance, in which both alleles are expressed in the phenotype.
More currently, Mendel's work has led to methods such as DNA hybridisation within a species. Individuals within species, who have desirable characteristics e.g. Labrador and Poodle, are bred so that offspring (Labradoodle) possess a favourable combination of characteristics from each parent. This stems from Mendel's findings, as he established that we receive an allele from each parent. Hence, this process relies upon the offspring inheriting the desirable traits from their parents.
Thus, Mendel's work has increased our understanding of inheritance, including alleles, genes and dominance, leading to many further developments.
Thank you! :)
Genetics is such a good topic to learn, because a lot of what is assessed in Genetics has already been highlighted in Blueprint of Life. You learn about protein synthesis in more depth, you learn about the role of introns and exons in establishing fingerprinting and VNTR in DNA fingerprinting, and why they are important to establishing a unique fingerprint.
It's such an interesting topic, because of how you can apply this to the Blueprint of Life topic, which already allows you to further your understanding of the Blueprint of Life topic, so I highly recommend you being taught by your school.
None of them are really equation-y because it's biology, but I'd DEFINITELY recommend communication. It's so interesting to learn, and you can relate it to real life which helps with on-the-go study such as when you see the colour red "my red cones are being stimulated" etc while you can't really relate genetics to everyday life. Also it's interesting to learn how you see and hear etc.
Thank you for your advice. Both of them sound really interesting but I work better with things I can see and observe in front of me, so I might vote for communication haha. Our school has done it for a while so I feel like they'd teach it better tooFrom memory, I believe that every option topic will have the extended response at the end.
Is communication a very content heavy topic? Is it likely to have a 8 mark question because they sound quite frightening to me? Any tips of how to tackle such questions
Thank you for your advice. Both of them sound really interesting but I work better with things I can see and observe in front of me, so I might vote for communication haha. Our school has done it for a while so I feel like they'd teach it better too
Is communication a very content heavy topic? Is it likely to have a 8 mark question because they sound quite frightening to me? Any tips of how to tackle such questions
From memory, I believe that every option topic will have the extended response at the end.
From memory, I believe that every option topic will have the extended response at the end.
Communications is VERY content heavy let me tell you. Theres SOO much memorising and i kind of hate it. I agree its interesting but its a bit much. If i had a choice i definatley wouldnt choose it tbh. Im not saying its a shit topic or anything, but it just ddnt work for me :/
and yeah the do have the 8 markers which are usually about cochlear implants and hearing aid which is okay
but i hate the brain and nurones part eeekkkkkkk
plus notes are quite hard to find too, but iv done my notes so maybe ill upload them later if anyone wants:)
Good luck!
Thank you for your advice. Both of them sound really interesting but I work better with things I can see and observe in front of me, so I might vote for communication haha. Our school has done it for a while so I feel like they'd teach it better too
Is communication a very content heavy topic? Is it likely to have a 8 mark question because they sound quite frightening to me? Any tips of how to tackle such questions
Hi there I was wondering if HBOCs (haemoglobin based oxygen carriers)
are sterile/physiologically inert?
Questions from the 2015 biology HSCQ7: You're correct in that thermoreceptors detect changes within the skin, but these thermoreceptors merely send a signal to the brain. The brain enacts on these messages and sends them back to the arterioles and muscles. So, it is a trick question because really, two things happen at or near X.
Q7 - why is the answer not thermoreceptors within the skin? Its them that detect changes from the norm temperature not the brain right?
Questions from the 2015 biology HSCQ15: this is a pretty tough question, so don't feel bad!
Q15 I'm at a complete loss as how to do
Questions from the 2015 biology HSCQ23:
Q23 - should the process not be DNA unzipping - how can we tell its DNA replication does DNA not also unzip during transcription
Q7: You're correct in that thermoreceptors detect changes within the skin, but these thermoreceptors merely send a signal to the brain. The brain enacts on these messages and sends them back to the arterioles and muscles. So, it is a trick question because really, two things happen at or near X.
For the full picture, we'd get:
Core body temp falls below normal -> Thermoreceptors detect these changes in the skin -> Hypothalamus (brain) enacts to these changes -> Signal is sent to the muscles and arterioles -> Return to normal body temp.
So, that's why the brain is the most correct answer.
Q15: this is a pretty tough question, so don't feel bad!
If we read the question properly, we can see that: individual plants have either yellow, red or orange flowers.
Right off the bat, this implies either co-dominance or incomplete dominance as three phenotypes are involved.
We can then eliminate dominant/recessive relationships (B)
Next, the sentence tells us that two plants contain different flower colours. This allows us to eliminate (A).
We now have an even 50/50 split between (C) and (D). The question tells us that the breeding experiment was carried out like Mendel did.
If we recall how Mendel crossed his plants, the parent plants had to be pure bred or homozygous, meaning that (D) cannot be correct.
(C) will be the final answer (based on elimination).
Q23:
I see what you mean -- transcription or DNA unzipping is the process by which the DNA strand is copied into the mRNA. To observe why it's not transcription, consider what the end result of transcription is and what the end result of DNA replication is from a top-down perspective of the model. If we ever get a model, we should always approach the model with a top-down focus (ie from the top and reading the model going down), because that's the intended direction of how they are made.
Transcription is simply the unwinding and unzipping of the DNA strands using the enzyme helicase. It splits the two strands into its leading and lagging strands, while elongation (which is a process under DNA replication) is simply the synthesis of the complementary base pair onto the leading strand or the "template" strand.
Both of these "processes" comes under the umbrella process we call: DNA replication, which is the preferred process to name. But really, transcription and elongation are procedures that finally accumulate to the process of DNA replication.
Hi,
I was wondering if anyone knew the distribution of the types of cones in the retina (red cones, green cones, blue cones). So like, what are the percentages of each.
Thanks!
does anyway know an easy was to remember the function of veins/arteries/capillaries :)
i like it remember it like this
Arteries take blood Away from the heart -- Arteries -> away
veins bring blood back to the heart
capillaries join the artieris and veins and are one cell thick
Hope that helps:)
Yup! makes sense
btw do arteries have valves or veins?
and what is the function of valves
Q23:
I see what you mean -- transcription or DNA unzipping is the process by which the DNA strand is copied into the mRNA. To observe why it's not transcription, consider what the end result of transcription is and what the end result of DNA replication is from a top-down perspective of the model. If we ever get a model, we should always approach the model with a top-down focus (ie from the top and reading the model going down), because that's the intended direction of how they are made.
Transcription is simply the unwinding and unzipping of the DNA strands using the enzyme helicase. It splits the two strands into its leading and lagging strands, while elongation (which is a process under DNA replication) is simply the synthesis of the complementary base pair onto the leading strand or the "template" strand.
Both of these "processes" comes under the umbrella process we call: DNA replication, which is the preferred process to name. But really, transcription and elongation are procedures that finally accumulate to the process of DNA replication.
i like it remember it like this
Arteries take blood Away from the heart -- Arteries -> away
veins bring blood back to the heart
capillaries join the artieris and veins and are one cell thick
Hope that helps:)
Transcription is copying DNA to mRNA not the unwinding of the DNA strand. Transcription is part of polypeptide synthesis not DNA replication.Oh, my bad! Haha, you're correct; transcription doesn't occur in the replication of DNA.
Hi! For a question that asks for you to describe the work of three named scientists who have contributed to our understanding of inheritance, would it be appropriate to address Sutton and Boveri together, as well as Mendel and Morgan? So sort of like a packaged deal; equating their work to that of one scientist since their ideas are pretty similar? Thanks :)
yes! That seems like a great idea! Putting them as one can really strengthen your argument. The great part of these questions is the freedom we get! However, you could argue that you are talking about 4 scientists, but I doubt marks would be lost on that technicalityOoh, good point! Thanks so much :D
More questions ;D ;D ;D1. The kidney functions by filtering the blood in the glomerulis, with all the filtrate entering the bowman's capsule (blood cells stay in the blood) then various substances such as glucose are reabsorbed in the proximal tubule, and water and salts are reabsorbed in the loop of henle and distal tubules. In the collecting duct some water and salts may also be reabsorbed if ADH and aldosterone hormones have been released. So basically it filters blood and reabsorbs what is needed.
1.How does the kidney function?
2.What is the interaction between T cells and B cells?
More questions ;D ;D ;D
1.How does the kidney function?
2.What is the interaction between T cells and B cells?
To answer your second question, when a phagocyte such as a macrophage presents an antigen on its MHCII marker, a specific T Helper cell will recognise it and bind. It will then release cytokines that stimulate the specific B cell with the same receptors to undergo clonal expansion and differentiate into B plasma cells and B memory cellsDon't worry, it's all relevant, I think the only part we don't look at for HSC is clonal expansion, but the extra knowledge doesn't hurt
(I do VCE so sorry if some of this isn't relevant) Hope this helps, good luck!
1. The kidney functions by filtering the blood in the glomerulis, with all the filtrate entering the bowman's capsule (blood cells stay in the blood) then various substances such as glucose are reabsorbed in the proximal tubule, and water and salts are reabsorbed in the loop of henle and distal tubules. In the collecting duct some water and salts may also be reabsorbed if ADH and aldosterone hormones have been released. So basically it filters blood and reabsorbs what is needed.Just a few nitpicky things - ADH is released in the collecting yes - but aldosterone is released in the ascending loop of Henle, and concerns salt reabsorption specifically (although it also causes water reabsorption due to changing the osmotic pressure).
2. Pretty sure when presented with an antigen helper T cells stimulate B cells to produce plasma B cells and memory B cells - but I'm a little rusty on this so you might wanna double check
Hiiii!
What is one of the limitations of Koch's postulates?
Don't worry, it's all relevant, I think the only part we don't look at for HSC is clonal expansion, but the extra knowledge doesn't hurt
More questions ;D ;D ;D
2.What is the interaction between T cells and B cells?
Hiii! Another question ;D ;D Analyse the ways in which theories in biology are tested and validated, using the theory of evolution as an example.
For line/curve of best fits, do we join the dots??No! Don't mean to come off as aggressive with that no, but whatever you do, do not join the dots for a line or curve of best fit
For line/curve of best fits, do we join the dots??dont connect the dots
Clonal expansion is part of clonal selection theory, formed by Macfarlane Burnet - which can be tested in the HSC as it is one of the dot points in the left hand column of the syllabus.Sorry what exactly is the clonal selection theory and clonal expansion? Don't think I've ever come across these terms before. My knowledge of Burnet is also kinda iffy - didn't he identify MCH I or II molecules as being present on cells that identified them as being part of ones own body, and so did not trigger the immune response?
Sorry what exactly is the clonal selection theory and clonal expansion? Don't think I've ever come across these terms before. My knowledge of Burnet is also kinda iffy - didn't he identify MCH I or II molecules as being present on cells that identified them as being part of ones own body, and so did not trigger the immune response?The clonal selection theory explains the process of immunological memory in the form of two lymphocytes. One of these lymphocyte act as the immediate combatant to the infection, while the other remains in the body in the form of memory cells. It is these memory cells that enable an individual to have immunity over these specific antigens. While Burnet was not the one who proposed this idea, he extended the pre-existing theories surrounding these experiments and publicised his findings, naming it 'the clonal selection theory'.
The clonal selection theory explains the process of immunological memory in the form of two lymphocytes. One of these lymphocyte act as the immediate combatant to the infection, while the other remains in the body in the form of memory cells. It is these memory cells that enable an individual to have immunity over these specific antigens. While Burnet was not the one who proposed this idea, he extended the pre-existing theories surrounding these experiments and publicised his findings, naming it 'the clonal selection theory'.Ahhhh I see thank you so much you may have just saved me some easy marks in the hsc!
Ahhhh I see thank you so much you may have just saved me some easy marks in the hsc!Lol, I personally wouldn't have called that easy marks, I'm still confused, I feel like all that just went in one eye and out the other
Hey Guys,It might be one of those tricky questions that ask you to refer to multiple dot points such as
Does anyone know what part of the Communication syllabus this question is referring to:
"Compare mechanisms in the human body for detection and perception of a range
of frequencies in visual and auditory communication"
Even if the question does not specifically ask, is it possible to use a table when answering a 'compare' or 'contrast' question? (And still get the full marks!!) ThanksFor sure! I do it all the time internally and I'm certain this counts externally too - I reckon it's the best method
For sure! I do it all the time internally and I'm certain this counts externally too - I reckon it's the best method
sounds pretty good but can't give a mark without a guideline :)
Hi could someone please help with this question? I don't really understand how to distinguish homeostasis and enantiostasis, and in which cases one is used over the other. The sample answer didn't really help me either :(Homeostasis: maintainance of a constant internal environment
HSC 2009
Q26: Describe how processes such as enantiostasis and homeostasis are used to maintain metabolic functions when salt concentration varies in plants living in estuarine environments.
Sample answer:
Homeostasis involves maintaining a constant internal environment to maintain metabolic functions. This is difficult if there are large variations in salt concentration. In organisms that use enantiostasis, other physical or chemical conditions are varied to compensate for the variations in salt concentration so the metabolic functions are maintained.
Homeostasis: maintainance of a constant internal environment
Enantiostasis: maintainance of functionality in a changing environment
Enantiostasis is how organisms that live in saline conditions deal with the fluctuations in their environment. They can do this by being either:
Osmoconformers: able to maintain metabolic function with a changing internal environment - eg. A starfish matches it's body fluids to the external environment so it doesn't gain or lose too much water via osmosis
Osmoregulators: keep internal salt levels within a narrow range - eg. Mangroves have leaves where they store salt and drop off, and pnumetaphores which try and stop as much salt coming in as possible, this tries to minimise salt in the organism
So basically the sample answer is trying to say that in saline environments (such as estuaries where the salt levels are constantly fluctuating) it is incredibly hard to maintain homeostasis due to osmosis. Therefore these organisms change their behaviours and/or internal environment so they can continue to function.
If you still don't understand let me know and I'll attempt to clarify :)
Thank you! It kind of makes sense :) So because it is too hard for organisms to maintain homeostasis in fluctuating environments they must change their metabolic functions? But what I don't understand is how these behaviours are not also considered processes to achieve homeostasis(e.g. how is it different to homeostatic salt regulation of aldosterone)? Also, how does osmosis interfere with homeostasis?In enantiostasis, the organisms don't change their metabolic functions, they change their internal environment. So in the case of the starfish the starfish will make its body more or less saline to match the external environment. This is different to homeostasis because in homeostasis the internal environment is kept constant, so in humans for example, the salt levels in our bodies stay more or less the same regardless of our environment.
Could someone please mark these?
Both are from the 2009 HSC
Sorry what exactly is the clonal selection theory and clonal expansion? Don't think I've ever come across these terms before. My knowledge of Burnet is also kinda iffy - didn't he identify MCH I or II molecules as being present on cells that identified them as being part of ones own body, and so did not trigger the immune response?
Hey Guys,
Does anyone know what part of the Communication syllabus this question is referring to:
"Compare mechanisms in the human body for detection and perception of a range
of frequencies in visual and auditory communication"
Homeostasis: maintainance of a constant internal environment
Enantiostasis: maintainance of functionality in a changing environment
Enantiostasis is how organisms that live in saline conditions deal with the fluctuations in their environment. They can do this by being either:
Osmoconformers: able to maintain metabolic function with a changing internal environment - eg. A starfish matches it's body fluids to the external environment so it doesn't gain or lose too much water via osmosis
Osmoregulators: keep internal salt levels within a narrow range - eg. Mangroves have leaves where they store salt and drop off, and pnumetaphores which try and stop as much salt coming in as possible, this tries to minimise salt in the organism
So basically the sample answer is trying to say that in saline environments (such as estuaries where the salt levels are constantly fluctuating) it is incredibly hard to maintain homeostasis due to osmosis. Therefore these organisms change their behaviours and/or internal environment so they can continue to function.
If you still don't understand let me know and I'll attempt to clarify :)
How is homeostasis used to maintain metabolic function though? As asked in the question. I was having trouble with this one as well
In enantiostasis, the organisms don't change their metabolic functions, they change their internal environment. So in the case of the starfish the starfish will make its body more or less saline to match the external environment. This is different to homeostasis because in homeostasis the internal environment is kept constant, so in humans for example, the salt levels in our bodies stay more or less the same regardless of our environment.Ok so when it is difficult for the organism to maintain homeostasis in a fluctuating environment, enantiostasis is used to maintain metabolic functions by which the organism changes with the environment? So that is where osmoconformers come in as they vary along with the environment. But how do osmoregulators vary along with the environment since they are keeping salt in a narrow range?
These processes are not considered as achieving homeostasis because the internal environment does change, where as in homeostasis it does not. Throughout this process the metabolic functions remain the same but the internal environment does not.
What I meant abuout osmosis impacting homeostasis:
In terms of estuarine environments osmosis can cause water to enter or leave an aquatic organism if there were no processes to regulate this. As you know, fresh water fish produce heaps of dilute urine to maintain their water levels, as water moves into the fish because it is more concentrated than the external environment, and salt water fish produce small amounts of concentrated urine to prevent water going out because the external environment is more saline than the fish. However, organisms in estuaries, where the water is brackish and can fluctuate in salt levels, can't change their function to deal with the salinity, so they change the internal environment to match the situation so that they can continue to operate
Is there a marking criteria? I do have acsess to a bunch of sample answers for these questions which I can mark against (and so far your answers are looking pretty good) but if there's a marking scheme that would make the assignment of a mark more accurate
Hi,
does anyone know what "hybridisation within a species" mean? At first I thought it was something to do with transgenic organisms, but is it more about cross breeding within a species (e.g. different dog breeds)
Ok so when it is difficult for the organism to maintain homeostasis in a fluctuating environment, enantiostasis is used to maintain metabolic functions by which the organism changes with the environment? So that is where osmoconformers come in as they vary along with the environment. But how do osmoregulators vary along with the environment since they are keeping salt in a narrow range?Ok from my understanding osmoregulators either have functions to keep salt in a narrow range or the avoid the changes eg. Some crabs bury themselves in the mud when the tides change to avoid salinity changes.
Hi,
does anyone know what "hybridisation within a species" mean? At first I thought it was something to do with transgenic organisms, but is it more about cross breeding within a species (e.g. different dog breeds)
Hiii!! When they ask 'outline how different antibiotics work' do you talk about the drug antibiotic and the antibiotic activated by B-cells?Antibiotics kill bacteria
Hiii!! When they ask 'outline how different antibiotics work' do you talk about the drug antibiotic and the antibiotic activated by B-cells?
just wondering in general for hsc science subjects if flashcards help in memorising and consolidating yr knowledge thx. Might try it out.
Could someone please mark these?
Both are from the 2009 HSC
Question 27 (8 marks)
Most offspring resemble their parents in a number of characteristics, but there are often some characteristics in the offspring that are unexpected.
Explain, using examples, how genetics and the environment can affect the phenotype of individuals.
Q28 Communication
e) Explain how an understanding of hearing mechanisms has been used to develop 7 technologies to overcome hearing difficulties.(7 marks)
Can someone please mark this?
I was a little unsure as to whether I took a valid approach to this question :( Also I'm not sure if competition for resources would be an acceptable point.
Much appreciated :)
Question and marking criteria are attached :)
Ok so I'm just getting sound to marking your responses based off criteria and sample answers.
DISCLAIMER: I am by no means a marking expert since I am also doing th HSC this year, and when I mark myself I tend to mark myself a mark or two harsher than what I actually think because of this, and I guess that pushes me a little
Ok so for 27, I think I would give it a 7. All the info was there, I just felt like its coherence could be improved slightly, but this isn't a major deal, since as previously stated, I try and mark harsher just in case.
For 28 e, I'm giving that a 7 too since it followed a very logical procedure and demonstrated a thourough understanding of how these technologies work to overcome hearing difficulties.
Good job!
For this question I think I'll have to give you a 5. Unfortunatley the top band requires you to talk about theories where as you only discussed Darwins theory of gradual evolution. To access the 6/7 marks you would have to also talk about punctuated equilibrium. This is where the birds come in, since many fossils appeared all at once. I feel you could also make more explicit links between the biological evidence and the theories, but maybe that's just me. Other than that I think you have a sound understanding and explained in a clear manner.
Hey could someone explain these 2 questions for me please?I'm on my phone so I can't give an extensive answer. For the time being, I'll just briefly explain the mc.
For the punnete square cross, I've forgotten how to draw it up when you have dihybrid crosses
Hi! For the genetics elective, can anyone explain the difference between endonuclease/exonuclease enzymes and DNA glycosylase in relation to the repair of damaged DNA? I was taught in class about glycosylase but found that a past HSC paper example response only mentioned endonuclease and exonuclease enzymes, which appear to have a similar function. Thanks :)
I'm on my phone so I can't give an extensive answer. For the time being, I'll just briefly explain the mc.Ahhhh I see that makes sense thank you!
Consider the sixth and the seventh couple on generation II. We notice that if it were recessive, then all of the offspring will not be affected; this suggests that the couple must be heterozygous dominant. This means the genetic inheritance being affected carries the recessive gene, which looks to be (C)
Hi! For the genetics elective, can anyone explain the difference between endonuclease/exonuclease enzymes and DNA glycosylase in relation to the repair of damaged DNA? I was taught in class about glycosylase but found that a past HSC paper example response only mentioned endonuclease and exonuclease enzymes, which appear to have a similar function. Thanks :)Is this for the genetics: the code broken elective? I study it as well but I've never heard of these terms (endonuclease and etc) - what syllabus dotpoints is this under?
Hi,
Can someone please clarify how metabolism changes for homeostasis?
I have read that when temperature is low, metabolism increases as energy is being taken up to generate heat in the body.
Yet when animals experience cold, their metabolism instead drops as they hibernate?
A quick summary of metabolism and temperature change would be nice :)
Hi av-angie-er,Ohh okay, thank you! Super helpful :)
Basically, endonuclease enzymes are able to cut double stranded DNA anywhere along the molecule, and exonucleases are only able to cleave DNA at the ends of the molecule. Both of types enzymes break the sugar phosphate backbone to cleave DNA strands.
DNA glycosylase does not cleave the sugar phosphate backbone, it only cuts out damaged nitrogenous base pairs, leaving a site for DNA repair.
These different enzymes would perform different functions in repair, depending on the extent of damage (i.e. whether a sequence + its sugar/phosphate backbone need to be removed).
Hope this helps!
External temperature increasing causes lower metabolism in ENDOTHERMS as it generates heat so they don't want too much metabolism. It causes higher metabolism in ENDOTHERMS as they are more active when it's hot.Alright the second bit makes sense so thank you!
When external temperature decreases, endotherm metabolism increases as cellular respiration generates heat. For ectotherms it decreases as they conserve body heat until it is warm enough to search for food efficiently as searching for food to replenish energy while it is cold would be inefficient.
Note that internal temperature for humans barely varies due to homeostasis so enzymes are always efficient while for ectotherms their internal temperature changes.
Alright the second bit makes sense so thank you!
But for the second bit:
You're saying temp increase causes higher metabolism in ENDOTHERMS as they are more active when it's hot. But hang on, don't they want to lower metabolism so they don't generate as much heat when its already hot? I thought animals like kangaroos reduced activity and metabolism in hot temperatures so they generated less heat?
I don't get the concept of threshold potential, can someone clear it out ? Thanks
I don't get the concept of threshold potential, can someone clear it out ? ThanksNot all stimuli generate a response, if they did we'd probably go crazy! Therefore the membrane potential must reach the -55 threshold (from a resting potential of -70) to stimulate an electrochemical signal, and thus response. It's like a gun, all or nothing, either the trigger is pulled or it doesn't.
No that's good, thank you! I definitely understand what you meant with the different theories of evolution, makes sense :) Also competition for resources and its role in evolution can be a bit confusing, but do you think what I have said about it in the above response makes sense?I know right! This where I lose my marks, I know all the content but I'm not sure what to write to make the markers happy. As for tips, I try and deconstruct the question and try and work out how many components there are to it and match that up to the question. So if it says compare and contrast X and Y and its 4 marks I tend to assume I get a mark for 2 simularities and 2 differences. I havnt quite worked out the trick to the longer ones though. When I have the marking guidelines it all makes sense but in the exam I have no idea what they want. As for the competition for recourse section, it made sense to me that without competition from mammals birds are able to occupy environmental niches, but I think it could be explained a tad more clearly and concisely.
Bio seriously stress me out because I feel like I never know if what I'm writing is going to match the marking criteria. Some questions in bio are open to many different interpretations and that makes it so stressful:( Any tips?
Hi there! This might be a silly question but I was wondering if there are any strategies or tips in answering questions along the lines of "Evaluate the reliability/validity of this experiment? How would you go about answering these questions (eg. Q 28a 2016 paper) Thank you ! :)Ok so, evaluate according to BOSTES/NESA = make a judgment based on criteria; determine the value of
Hi! When a question refers to the 'management' of a disease, would this include both the prevention and treatment of it? For example, would vaccination be appropriate as a method of managing a disease even though it's administered as a measure of prevention before the disease is contracted and needs to be 'managed'? Probably a silly question, but thanks in advance! :)
Not all stimuli generate a response, if they did we'd probably go crazy! Therefore the membrane potential must reach the -55 threshold (from a resting potential of -70) to stimulate an electrochemical signal, and thus response. It's like a gun, all or nothing, either the trigger is pulled or it doesn't.THat's pretty dope, you're amazing, ty fam
When the response is triggered the electrochemical signal is generated by making the normally negative inside, positive. This is done by opening sodium channels. The more sodium that's let in, the easier it is for more sodium to come in, and so the inside becomes positive and the out side negative. (Depolarisation)
Once the signal has been generated and sent along the neurone the negatively charged inside is restored by removing potassium ions. This causes the downward turn of the graph (repolarisation)
When graphing action potential there's also a little dip below the resting membrane potential (hyperpolerisation) which is just to create a break between signals so we aren't constantly buzzing with constant streams of infomation.
I'm hoping that cleared things up
Hi, can someone please help explain why the answer for this question is C? thank youY chromosome is not in a pair of homologous chromosomes.
(https://i.imgur.com/vL7OZle.png)
Hi, can someone please help explain why the answer for this question is C? thank youNo crossing over occurs since a pair of homologous chromosomes entail one paternal and one maternal chromosome for each pair. Since females do not have a Y chromosome, there is no partner for the Y chromosome supplied by the male, and hence, crossing over cannot occur as this only happens with identical chromosomes (homologous pairs)
(https://i.imgur.com/vL7OZle.png)
Hi! I'm no expert so my answer may not be totally correct, but I'll help how I can. First of all, are you referring to a particular question? If so, is it specifically about non-infectious disease? I have found that 'management' itself has to do with how one copes with/responds to a non-infectious disease once they have it; similarly to 'treatment', as infectious diseases aren't really 'managed' - but rather controlled and eventually (hopefully) defeated by the immune system. To talk about this further we'll want to refer to two particular parts of the syllabus:Hey! Thanks so much for your answer, it was really excellent and beyond helpful :) As for whether or not I was addressing a question that specifically asked for an answer about non-infectious disease, the question that caught my attention was:
Identify data sources, gather, process and analyse information from secondary sources to describe one named infectious disease in terms of its: cause, transmission, host response, major symptoms, treatment, prevention and control.
Identify data sources, gather information from secondary sources to analyse and present information about the occurrence, symptoms, cause and treatment/management of a named non-infectious disease
So basically one of these requires an in depth study of an infectious disease and the other requires an in depth study of a non-infectious disease. The specifics that each dot point asks for, however, are slightly different. For infectious disease you do not need to know about 'management', which to me implies that one only 'manages' a non-infectious disease. I believe this would be the case especially in terms of incurable disorders, where the focus is on alleviating the symptoms and improving a person's quality of life, rather than preventing or controlling it as you would an infectious diseases.
The infectious disease I focused on was Cystic Fibrosis: an incurable genetic disorder. Some of the examples I have under 'treatment/management' are 'antibiotics to treat lung infections', 'enzyme replacement tablets to aid food digestion' and 'salt and vitamin supplements'.
Hope this helps!
Do antibodies work on intracellular pathogens and do cytotoxic t cells work on extracellular pathogens? ThanksIt's the other way around :) Plasma B cells secrete antibodies which mediate the humoral immune response, whereby the antibodies move through the blood and lymph fluid to attack extracellular microorganisms. Conversely, T cells control the cell-mediated response, which involves the activation of cytotoxic T cells, phagocytes and various cytosines that destroy intracellular pathogens. Hope this makes senses :D
It's the other way around :) Plasma B cells secrete antibodies which mediate the humoral immune response, whereby the antibodies move through the blood and lymph fluid to attack extracellular microorganisms. Conversely, T cells control the cell-mediated response, which involves the activation of cytotoxic T cells, phagocytes and various cytosines that destroy intracellular pathogens. Hope this makes senses :D
Oh yeah I meant like can they work on the opposite type too e.g. can cytotoxic also kill extracellular and can antibodies help with intracellular?
Hi!
I was just wondering, as someone just starting their HSC course, what books/textbooks would you recommend using as notes and studying for Biology?
Thank you :))
Does anyone know the difference between random segregation and independent assortment, and what phase of meiosis they each occur in? I've looked at heaps of definitions, videos and explanations and I still feel like they are just different explanations of the same process?I could he wrong bit pretty sure independent assortment is when they all line up along the middle in their pairs before the first split and random segregation is where the two copies of the chromosome split in the 2 split. I don't know what phases they are cause we were told we wouldnt need to know the phase names so i never tried leaning them
Hi all - What are the top 10 diagrams we should know how to draw for the cores heading into the exam???
Hey I was wondering if someone could give me a guide on how to graph? In never know whether to do column / dots with straight or curved lines/ where the dependent or independent variable goes!
Thanks heaps :)
Never do column graphs unless it asksThanks so much !
Always do crosses not dots to plot your points
Independent variable on the x axis
Usually you join up the dots if it looks linear but if not do freehand. Also if it says line of best fit do that.
Hi!
I was just wondering, as someone just starting their HSC course, what books/textbooks would you recommend using as notes and studying for Biology?
Thank you :))
Hi, for the communication elective do we have to understand how depth perception works and how we see things three dimensionally? because I'm seeing questions on it in old papers (e.g. 2003), but I have no notes on it and idk where it corresponds to in our syllabus
Hi all - What are the top 10 diagrams we should know how to draw for the cores heading into the exam???
hi there what is the difference between random segregation and independent assortment during meiosis? thanks heaps!
hi there what is the difference between random segregation and independent assortment during meiosis? thanks heaps!
Can someone please help me with this question and also explain it... there are no marking guidelines for 2007 hsc bio so I don't know if I'm doing it right.
So for part a) I would talk about:
- independent assortment: the chromosomes have randomly lined up in the centre with their homologous pair
- crossing over: the inner chromatids of the AB and ab chromosomes have crossed over to form new allele combinations
For part b), the allele combinations would be 1. ABDE 2.AbDE 3.aBde 4. abde
To figure this out, I just imagine the four gametes that would be produced. In this case they have shown the two sets of chromosomes moving to opposite sides of the cell to form two cells for the next phase, so we know that in prophase II one cell has the AB/Ab and DE/DE chromosomes while the other cell has the aB/ab and de/de chromosomes.
- In that first cell (AB/Ab and DE/DE) the chromosomes will again line up randomly and go through the process to produce two more cells. Each of these two cells should have one allele of each of the genes so if you just imagine them separating into the chromatids you can see one cell will have an ABDE combination and the other will have an AbDE combination of alleles.
- repeat this with the other cell with prophase II (aB/ab and de/de) and the combinations produced would be aBde and abde
Thus, the four combinations produced would be ABDE, AbDE, abde, abde
Hope that was helpful and sorry if that explanation was kinda complicated lol! Please feel free to clarify anything
So for part a) I would talk about:Your method of doing part b makes heaps of sense, but I'm confused about the answers on the success one HSC Bio book
- independent assortment: the chromosomes have randomly lined up in the centre with their homologous pair
- crossing over: the inner chromatids of the AB and ab chromosomes have crossed over to form new allele combinations
For part b), the allele combinations would be 1. ABDE 2.AbDE 3.aBde 4. abde
To figure this out, I just imagine the four gametes that would be produced. In this case they have shown the two sets of chromosomes moving to opposite sides of the cell to form two cells for the next phase, so we know that in prophase II one cell has the AB/Ab and DE/DE chromosomes while the other cell has the aB/ab and de/de chromosomes.
- In that first cell (AB/Ab and DE/DE) the chromosomes will again line up randomly and go through the process to produce two more cells. Each of these two cells should have one allele of each of the genes so if you just imagine them separating into the chromatids you can see one cell will have an ABDE combination and the other will have an AbDE combination of alleles.
- repeat this with the other cell with prophase II (aB/ab and de/de) and the combinations produced would be aBde and abde
Thus, the four combinations produced would be ABDE, AbDE, abde, abde
Hope that was helpful and sorry if that explanation was kinda complicated lol! Please feel free to clarify anything
So for part a) I would talk about:
- independent assortment: the chromosomes have randomly lined up in the centre with their homologous pair
- crossing over: the inner chromatids of the AB and ab chromosomes have crossed over to form new allele combinations
For part b), the allele combinations would be 1. ABDE 2.AbDE 3.aBde 4. abde
To figure this out, I just imagine the four gametes that would be produced. In this case they have shown the two sets of chromosomes moving to opposite sides of the cell to form two cells for the next phase, so we know that in prophase II one cell has the AB/Ab and DE/DE chromosomes while the other cell has the aB/ab and de/de chromosomes.
- In that first cell (AB/Ab and DE/DE) the chromosomes will again line up randomly and go through the process to produce two more cells. Each of these two cells should have one allele of each of the genes so if you just imagine them separating into the chromatids you can see one cell will have an ABDE combination and the other will have an AbDE combination of alleles.
- repeat this with the other cell with prophase II (aB/ab and de/de) and the combinations produced would be aBde and abde
Thus, the four combinations produced would be ABDE, AbDE, abde, abde
Hope that was helpful and sorry if that explanation was kinda complicated lol! Please feel free to clarify anything
Your method of doing part b makes heaps of sense, but I'm confused about the answers on the success one HSC Bio book
it says that for part b) answers are AE, BD, bD, ae, Bd, bd
I'm confused because why would alleles for non homologous chromosomes (idk what you call them) mix together?
Hey, how do I stop writing excessivley long answers for the core component of the exam?
I just practiced a 5 marker for blueprint of life and spent almost a page answering it, we wont get that much space in the exam though so how do I make it more concise?
For q19, I thought opening stomota's would result in the plant become less cool, as its the site of water loss. Is it meant to be because it inititates the transpiration pull of water up the plant, thus cooling it maybe?
Hey could someone help me out with these 2 questions from the 2012 HSCHey! For the first question bacteria are procariotic cells so by elimination it's a protozoan.
Membrane bound organelles means it cannot be a virus or prion, but I''m not sure where to go from there.
For q19, I thought opening stomota's would result in the plant become less cool, as its the site of water loss. Is it meant to be because it inititates the transpiration pull of water up the plant, thus cooling it maybe?
Hi everyone -- not sure if this has been asked before but does anyone know of a good example for a transgenic animal? Info on oncomouse seems a bit limited..I think there are a type of salmon by I can't remember the name! Do we need to know an animal?
Hi everyone -- not sure if this has been asked before but does anyone know of a good example for a transgenic animal? Info on oncomouse seems a bit limited..
Hi!
bGH (Bovine Growth Hormone) is inserted into salmon, which results in larger + faster growing fish :)
Hey this is the method i have for how to produce a transgenic species and i just wanted to make sure it was correct or if it had too much/too little detail? Thanks!Yeah that's pretty much it in terms of detail. Just remember it's the enzyme ligase which helps the gene stick to the bacteria plasmid. Also make sure you know a few ways the gene is inserted into the genome (i.e. micro-injection of DNA, gene gun, and using a virus) but I see you have briefly mentioned it
1. Identify desired gene
2.Isolate genes using restriction enzymes that cuts out sections of DNA from both organisms (often bacteria) so sticky ends of DNA match, creating recombinant DNA when inserted into the genome of the second organism (the plasmid of the bacteria)
3. Make multiple copies of the gene
4. Insert gene into the organism/culture and infect a tissue with it.
can someone help me with this question?
It's from 2015 HSC paper - q15
I thought the answer was A, but apparently it's C.
Someone please explain...
hi there was just wondering what the difference was between cell differentiation and cell specialisation?
Hi! Does anyone know if we need to know anything about complement proteins and neutrophils in the 2nd line of defence (or just macrophages)? Thanks!Hey there as its so complex i think we just need to know about macrophages
Hey there as its so complex i think we just need to know about macrophages
Hi everyone -- not sure if this has been asked before but does anyone know of a good example for a transgenic animal? Info on oncomouse seems a bit limited..Idk many animals but you could do strawberries with the antifreeze salmon gene or by cotton...
Hello :)
From what I understand, cell differentiation is the process by which cells become specialised. That is, stem cells differentiate to become muscle cells, skin cells, blood cells, etc and their specialisation is the function they carry out i.e. red blood cells carry oxygen. Though it is more complex, differentiation is like the 'structural' differences and 'specialisation' refers to the switching on of specific genes, so that the cell carries out specific functions. That's all I'd suggest you know for HSC :)
Hey guys, just wanted to ask if a flowchart counts as a diagram? Say the question was "Draw a diagram showing the path of soundwaves", could I just show it in a flowchart or would I have to draw a diagram of the ear?
Hi! Does anyone know if we need to know anything about complement proteins and neutrophils in the 2nd line of defence (or just macrophages)? Thanks!
Hi, could someone please help explain why the answer is D? I just don't know how we're meant to use our prior knowledge to work it out - because aren't dissolved nutrients carried in the phloem? (I don't think the phloem would be on the outer layer of the bark, idk tho)
(https://i.imgur.com/oUNnxiD.png)
anyone know how to do q 18 of the 2010 paper? It's just a simple calculation but I can't seem to get it!
anyone know how to do q 18 of the 2010 paper? It's just a simple calculation but I can't seem to get it!
heey im really lost,
so we have citrus greening which occurs due to the psyllid insect but we also have another citrus disease where citrus fruits borers tunnel into the rind of citrus fruits? and is this the same as fruit flies? which one should i use?
(this is for the quarantine dotpoint)
Hi, just wondering if we need to know about plant grafting? Also what's the difference between that and root culturing? Thanks!
hey could someone please explain this answer for a multiple choice from 2015 hsc paper?
1. An extremely high concentration of carbon dioxide is undesirable in active muscle tissue because it will:
Answer is: A) increase the pH.
----> wouldn't this cause the blood to be more alkaline, not acidic?
Also are we supposed to know the size of pathogens in relation to different cells as there was question 9 from the same paper that showed a redblood cell and a a larger cell with cell wall and membrane next to it and we were supposed to the know that the cell was a fungi?
Thanks heaps!
Hi, could someone please help me with Q7 and Q18 from the 2015 paper?Hey haha I just did that paper too. For question 7 it's just skipped a few steps and jumped straight to where the message would have been processed by the brain and a corrective response sent for.
https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-biology.pdf
I don't really understand the diagram for Q7. And for Q18 I don't get why there's 2 independent variables - because if they're determining the optimum pH isn't the pH the only thing they're changing?
Hey haha I just did that paper too. For question 7 it's just skipped a few steps and jumped straight to where the message would have been processed by the brain and a corrective response sent for.for 18 the correct answer is B tho - 2 IV rather than 4
For the next one I just went off the face that an independent variable is something you change so you changes he ph for four different types of enzymes ( imagine maybe that you were doing four separate experiments ) meaning there were 4 IV
for 18 the correct answer is B tho - 2 IV rather than 4
Hey, I'm not sure how to answer this question as I'm a bit confused as to which dot point it refers to and which examples to use:
Relate specialised features of the eyes of TWO named animals to their environment (2 marks)
Humans have rods and cones in the retina which allow for colour perception and sight in general to navigate around, communicate, and for depth perception.
Flies have a compound eye with thousands of ommatidia which provide dots of shade and colour to indicate predators or prey with a change in colour/shade.
Hi, does anyone know how much info we have to know about Macfarlane Burnet? I've honestly learnt nothing about him in bio class, but I've come across the occasional question about him...I dont think we need to know much, just who he is and what scientiffic knowledge he contributed to. It rarely comes up though.
Hi, does anyone know how much info we have to know about Macfarlane Burnet? I've honestly learnt nothing about him in bio class, but I've come across the occasional question about him...
heey guys, in the dotpoint for analysing methods for purifying drinking water, do we need to give the disadvantages of methods of water purification??
Hey!
How does Aldosterone help with water retention?
Wouldn't an increase in solvent concentration make it worse, especially when dehydrated?
Yet, when we are dehydrated, Aldosterone is still secreted...
Aldosterone increases sodium reabsorption but decreases potassium reabsorption. Increased sodium (main solute of blood) = higher concentration of sodium in blood compared to water, meaning the concentration of water in blood decreases (relative to sodium, so this decrease in water conc. doesn't meant the actual water levels have decreased). So, more water from distal tubule and collecting duct is reabsorbed via osmosis as water moves from high concentration to low, compensating for the decrease in water concentration (thus increased water retention).
This makes a lot of sense but why isn't ADH just released instead because doesn't it increase reabsorption of water? These two always confuse me a lot idkYeah, ADH also increases reabsorption of water- but directly by making the distal and collecting tubule more permeable to water. I think ADH is used when there's already high sodium levels in blood but also low water levels, so use of aldosterone would make sodium levels too high. (I'm not entirely sure though, just my guess as to a reason why)
This makes a lot of sense but why isn't ADH just released instead because doesn't it increase reabsorption of water? These two always confuse me a lot idkI learnt it a different way, when sodium ions are reabsrobed as a result of aldosterone, water follows via omosis and therefore is also reabsorbed. This leads to increase in blood volume and blood pressure.
Aldosterone increases sodium reabsorption but decreases potassium reabsorption. Increased sodium (main solute of blood) = higher concentration of sodium in blood compared to water, meaning the concentration of water in blood decreases (relative to sodium, so this decrease in water conc. doesn't meant the actual water levels have decreased). So, more water from distal tubule and collecting duct is reabsorbed via osmosis as water moves from high concentration to low, compensating for the decrease in water concentration (thus increased water retention).
Hey guys dotpoint from SFBH what are the distinguish features of every pathogen - e.g. prion's are the only pathogen with no genetic information at all.marcoparasites man...
Also, what are bigger fungi or macroparasites?
Hey guys dotpoint from SFBH what are the distinguish features of every pathogen - e.g. prion's are the only pathogen with no genetic information at all.Prions are non-cellular and they are proteins that can fold abnormally. They lack genetic material, such as DNA or RNA.
Also, what are bigger fungi or macroparasites?
Prions are non-cellular and they are proteins that can fold abnormally. They lack genetic material, such as DNA or RNA.Thank you so much! Could someone also explain the lymph system in the 2nd line of defence for me please
Viruses are non-cellular and they are made of the genetic material of DNA or RNA, surrounded by an enveloped by a protein coat. The complete package (virus + protein coating) is called a virion. Viruses require a host cell to survive, and reproduce by injecting itself into the host cell. The host cell contains genetic material that then is used to make new viruses, splitting the host cell and exposing the virus.
Bacteria are prokaryotic (meaning they are single celled and do not contain a membrane bound organelle), and they reproduce through a process called binary fission. The bacterial cell splits into two halves, which then produces two new cells that have the capacity to grow to the size of the parent cell. A bacterium is living.
Fungi can be uni or multicellular, and they are eukaryotic organisms. They have a cell wall, composed mainly of chitin. Fungi reproduce by budding, spores, or fragmentation. They are living and motile.
Protozoan are single celled organisms. They are motile, and usually require a vector for transmission.
Macro parasites are the largest pathogens, they can be seen by the naked eye.
Thank you so much! Could someone also explain the lymph system in the 2nd line of defence for me please
Also, do we have to know the different types of phagocytes e.g. neutrophils, macrophages
Hi, could someone please help explain the answers for Q19 and 20 for the 2014 paper?
https://www.boardofstudies.nsw.edu.au/hsc_exams/2014/pdf_doc/2014-hsc-biology.pdf
Does someone have a simple definition for recombinant DNA? i'm struggling to understand what exactly it encompasses, is it just DNA which has been genetically altered in some way? Thanks!Essentially, recombinant DNA is an artificially-made DNA strand formed by the combination of two or more gene sequences. :)
Could someone quickly give a rundown about all the action potential stuff? (Part of Option topic: Communications)
Thanks!
Quick question: do we need to know about 2 kinds of artificial blood? Or is 1 enough?Considering the difficulties of the exams this year, I think it's better to know about both kinds: perfluorocarbons, and haemoglobin-based oxygen carriers.
Also, what's the difference between photopsin and iodopsin? The text book says one and some youtube videos say the other, but I think they're pretty much the same as they're both describing the photosensitive pigment in cone cells?
Considering the difficulties of the exams this year, I think it's better to know about both kinds: perfluorocarbons, and haemoglobin-based oxygen carriers.
I would also recommend outlining the disadvantages and advantages for each.
Hi there, anything in particular we are recommended to do today being the day before the bio exam?
Maybe read over your notes and work on your weak points? I personally saved all the multiple choice from 2016-2004 for a chill study sesh today lol
Hey, I've been going through some past papers and i'm so stuck on what is actually required for this question (method? variables? equipment?), any ideas would be greatly appreciated!
"Plant breeders have developed a new variety of terrestrial plant which has one structure
that appears to assist in water conservation in hot, dry environments.
Design a first-hand investigation the plant breeder could use to determine of this structure
assists in water conservation." (4 Marks)
Hi can anyone please help me with this dot point in MAB "inadequacy of diffusion and osmosis in waste removal". Here's an outline of my notes on it. Just wanna know if these are enough of if there are any errors. Thanks :)
- Not fast enough to maintain required solute concentration in the cell and to remove significant buildup of nitrogenous wastes
- Slows down once the difference in concentration gradient becomes smaller and stops once concentrations have hit equilibrium
- Diffusion: toxins can only be removed if there was a high concentration of it in the blood than in the urine itself.
- Osmosis: would only remove toxins if it is dissolved in water; if there is a high concentration of urine, water will continually be drawn out from the body to even out the concentration gradient.
I've got so many last minute q's sorry! Would someone be able to help me with this dot point in the genetics option: "explain how the use of recombinant DNA technology can identify the position of a gene on a chromosome" - is it okay just to talk about the FSH method here? Also what would come under "identify the role of genes in embryonic development", I'm really lost with this one and can't really find anything online. Thank you so much!Yeahh, but you need to go in great detail about the process of "Fluorescent In Situ Hybridisation".
For HSC bio exam do we draw in pencil or pen? because it says to only use black pen.Pen. If you're unsure, do it in pencil first then trace over with pen. this is because the papers are scanned (I think markers were given physical copies in the past), and pencil wouldn't be able to show well
Yeahh, but you need to go in great detail about the process of "Fluorescent In Situ Hybridisation".
Talk about probes as a sequence of DNA that has been prepared through the process of recombinant DNA technology.
Talk about how the probe is annealed so that the DNA denatures.
Talk about the binding of the probe to the actual gene (by complementary base pairing).
Talk about how the probes are then placed under electrophoresis gel, where the probes can then be used to identify the locus of the gene along a chromosome.
Role of genes:
We have two main genes that compose of embryonic development:
The first one is called a structural gene, and these encode for polypeptides that code for the proteins and enzymes of the embryo.
The second one is called a regulatory gene, and these control the expression of the structural genes.
We also have a third gene, a homeotic gene that encodes for the patterns of development within the early stages of embryonic development.
Okay thank you so much!!! Just about the electrophoresis gel - why is that used here? I thought fluorescence microscopes were used to identify the position of the probe on the chromosome?Ahah, my mistake. Gel electrophoresis is used in DNA fingerprinting.
Stupid question but, in humans the diploid number is 46 therefore every cells has 23 pairs of homologous chromosomes. However in males the X and Y chromosomes are not homologous, so do we still say that they have 23 pairs?You can still say that males have 23 pairs. Just that 22 pairs (of autosomes) are homologous and 1 pair (of sex chromosomes) isn't. In general if you say something like "humans have 23 pairs of chromosomes" it'll be fine.
You can still say that males have 23 pairs. Just that 22 pairs (of autosomes) are homologous and 1 pair (of sex chromosomes) isn't. In general if you say something like "humans have 23 pairs of chromosomes" it'll be fine.Alright thanks for clarifying haha
Alright thanks for clarifying haha
For gene therapy in genetics could someone also explain the difference between ex vivo and invo gene therapy. Also, for producing linkage maps, the dihybrid cross must be between 2 homozygous recessive and double heterozygous correct?
Hey,
I'm just a bit confused about Sutton & Boveri's contributions, like what did they establish at the end of the day?
I can't seem to figure out what they did, and if they both found out the same thing about chromosomes.
Yeah I think the main idea is that they are slow and passive processes and it's inadequate for larger organisms because they build up toxins quickly and therefore need more efficient processes to remove waste
Hello! Would they ever ask us to design an epidemiological study?
There was an 8 marker asked in a HSC paper, I can't remember when but it was a fairly older paper I think. It gave a scenario and you had to discuss how an epidemiological study could be used to find the cause of the infections disease. So I guess the general answer to your question is: yes they can, unfortunately :/
There was an 8 marker asked in a HSC paper, I can't remember when but it was a fairly older paper I think. It gave a scenario and you had to discuss how an epidemiological study could be used to find the cause of the infections disease. So I guess the general answer to your question is: yes they can, unfortunately :/it was in the 2004 paper
How would I go about answering this question? I'm stumped.
I'm no expert, but I would break the question down in correspondence to the 4 marks that are allocated to it. In general, I would focus on the main features that you know are a part of an epidemiological study and just link it to the scenario given by the question:
1. Create a large population sample of individuals with diverse backgrounds, including living in different areas, differences in age and gender, occupation, lifestyle, etc
2. Gather data on the eating habits of those affected and those not affected, paying particularly attention to if fish is the main food source or meat, due to the recent chemical factor that had started up nearby.
3. Gather data on the location the individuals affected and not affected live: i.e if they live near the far side of the bay where the chemical factory is situated
4. Compare the data gathered on the affected and control groups and interpret for trends: i.e: similarities, differences. You could also potentially make a prediction as to what the cause of the symptoms may be, which, judging from the information provided, you could hypothesise that it is the chemical run-off from the chemical factory into the water that the fish, which is the main food source for town, live. Thus, individuals who eat a diet mainly of fish have contracted the disease.
What HSC paper is it from?
This is from a trial paper I found online
They together determined that Chromosome Theory of Inheritance: that patterns of inheritance in mammals matched those established by Mendel and his pea plants. So, they found that the law of random segregation, the law of independent assortment, and the law of simple dominance applied in mammals by testing sea urchin eggs, in relation to Boveri, and grasshopper testes, in Sutton's case. It is important to note that each of them were observing the process of meiosis in each of these two different organisms, hence the fact that these same laws applied to them enhances the reliability of the theory. This theory also includes that chromosomes are found in the nucleus, where previously it was thought to be found in the cytoplasm AND the nucleus, and that fertilisation allows new pairs of chromosomes to form as those that randomly segregate/independently assort come together.
And to answer the latter part of your question, they found out slightly different things that all contributed to the one theory explained above!
There are heaps of youtube videos on them if you need further clarification.
Hope that makes sense :)
Can anyone explain the functions of DNA helicase and DNA polymerase??DNA Helicase is responsible for the "unzipping" of DNA during RNA replication - this creates the exposed strand where new, complementary nucleotide bases are then added - DNA Polymerase is what catalyses the addition of these new bases. Both are enzymes
hey guys would someone mind describing the lung cancer dot point for epidemiology? Do we have to know the names of specific studies?
Thanks!!
What exactly do we have to know about the structures of xylem and phloem?
Can i use down syndrome as an example of an inherited disease?
Can i use down syndrome as an example of an inherited disease?No down syndrome isn't generally inherited as it's a mutation of the 21 chromosome and cos most peeps with down syndrome don't reproduce.
Can anyone explain the functions of DNA helicase and DNA polymerase??I know there's a genetics elective or something, so bear in mind this is just info from blueprint. DNA helicase is an enzyme that catalyses the unwinding of the double helix. DNA polymerase breaks the bonds between the bases of nucleotides, and it also checks to see whether the new bonds (during DNA replication) match (e.g. A with T, G with C)
Hey guys, just a quick question, does the fluid inside the cochlea pass through the Reissner and Basiler membrane into each canal, or does it just provoke other fluids located in different canals to transfer mechanical energy?The latter- the fluid (perilymph and endolymph depending on which chambers) in the different chambers don't actually mix because of the membranes separating them. instead, like you said, they push on each other from pressure from round window, transferring mechanical energy
No down syndrome isn't generally inherited as it's a mutation of the 21 chromosome and cos most peeps with down syndrome don't reproduce.
Pen. If you're unsure, do it in pencil first then trace over with pen. this is because the papers are scanned (I think markers were given physical copies in the past), and pencil wouldn't be able to show well
I think just know a brief outline of the epidemiological study by Hill and Doll from the 50's in the UKhey thanks! I've just got limited stuff on the Hammond and Horn study in the US - I think they surveyed 1 million people but did a follow up of 180 000 men for mortality to determine the link so hopefully that's enough, imight briefly mention the hill and doll study too.
so like the case study: by collecting data on the occurrence of the disease to identify the impacts of age, race, geographic specificity
e.g. lung cancer incidence was higher in UK than Japan and try to form a hypothesis for the etiology of the disease (E.g. could be due to increased smoking since WW2 or from increased construction of roads etc)
then they did a case control by determining the frequency of the determinant (smoking) in diseased and non diseased individuals
e.g. they asked 650 lung cancer sufferers and only 2 didn't smoke --> so there is a correlation b/w smoking and lung cancer
but this sample size was too small so they did a cohort study following 40,000 doctors for like 40 years or something where they one group is exposed to the determinant whereas the other isn't (analytical study)
and then Doll found the odds ratio b/w smoking and lung cancer to be like 9.01 and anything above 1 suggests there is a causal relationship
hope this is right lol
not sure if u needa know that much detail
Hey there, just wondering do we need to know the mechanisms that allow interaction between B and T lymphocytes?? If so, what are they? :DD
Hii wondering what type of adaptation sunbaking is? e.g. central netted dragon sunbake during the morning to absorb heat which activates their daily body functions.
also during day their skin becomes lighter? what type of adaptation is this too?
help!!
a) outline the processes used to prodice a NAMED transgenic species. (3 marks)
b) Describe the environmental issues that arise from the species you describes in part a). (3 marks)
i was gonna do strawberries will the antifreeze gene from salmon but then that wouldnt make sense in part 2 cos it doesnt really arise any environmental issues
help!!
a) outline the processes used to prodice a NAMED transgenic species. (3 marks)
b) Describe the environmental issues that arise from the species you describes in part a). (3 marks)
i was gonna do strawberries will the antifreeze gene from salmon but then that wouldnt make sense in part 2 cos it doesnt really arise any environmental issues
Where in the kidney does active transport and passive transport take place? I know the obvious such as glomerulus --> bowmans capsule passive, proximal is active. However when sodium and water is reabsorbed by Aldosterone and ADH, is that also active transport or passive? Also, just to double check Aldosterone is released in the ascending loop of henle and ADH in the collecting tube correct?I think passive is like all the water reabsorption (osmosis), and filtration due to the high pressure of blood flow at the bowman's cap/glomuerulus, but when glucose and amino acids are reabsorbed at the proximal tubule, that is active transport as it moves against the concentration gradient . I think salt is also reabsorbed via active transport.
Hey guys, sorry if this is a stupid Q, but how does bio-geography support the theory of evolution? I'm a bit hazy when I explain it in an answer.Nah it isn't a stupid q.
Thanks!
Where in the kidney does active transport and passive transport take place? I know the obvious such as glomerulus --> bowmans capsule passive, proximal is active. However when sodium and water is reabsorbed by Aldosterone and ADH, is that also active transport or passive? Also, just to double check Aldosterone is released in the ascending loop of henle and ADH in the collecting tube correct?
Pretty sure anywhere that salt is absorbed, that's active transport (goes against concentration gradient), while absorption of water is passive transport. Aldosterone increases the absorption of salt, which is active transport since it goes against the concentration gradient. But as a result of this, water follows due to osmosis (passive transport). As for ADH, it just increases the absorption of water, so passive transport only.
From what I have in my notes, ADH is released in the collecting duct, while aldosterone is released in the distal convoluted tubule? You should wait for someone else's reply too for a second opinion though haha
Both aldosterone and ADH act on the distal and collecting tubule. Also adding to this there's also secretion- urea diffuses in at the proximal tubule, whereas hydrogen ions moves into the distal tubule via active transportReally i thought urea was present in blood and entered the bowmans capsule through the glomerulus? Secretion was only for drugs and poisons in my notes
Really i thought urea was present in blood and entered the bowmans capsule through the glomerulus? Secretion was only for drugs and poisons in my notes
hey guys, how much information to people have for the dot point on the social and political impacts/influences of developing theories of inheritance? the only thing i really have is the whole "they threatened creationist views" but ??Here are my notes, I hope you don't mind that I lazily copied and pasted them. but you definitely don't need to know that much detail, I think the dot point hasn't even been assessed before (not sure tho)
Hi, does anyone know the range in the electromagnetic spectrum that humans, snakes, and bees can see?Hey,
my notes says the range for humans is 380-750nm, but wikipedia says it's 390-700nm
Yeah, secretion involves drugs and poisons but there's more than that. Urea is filtered in bowman's capsule, but not 100% so some secretion is involved . Here's a brief diagram in my notes, it doesn't cover everything thoThank you so much! Could someone also help me out with this question please
(https://i.imgur.com/HQy0wrJ.png)
Thank you so much! Could someone also help me out with this question please
It would be B because they give you the tRNA so you have to go backwards twice to find the mRNA and then the original DNA:)ahhhh that makes sense i misread the question and thought they meant mRNA woops!
ahhhh that makes sense i misread the question and thought they meant mRNA woops!
I know this has been asked a million times but, what is the difference between hybridisation and selective breeding?
Hi I know this is rather late, but I’m really struggling to wrap my mind around interaction between T and B lymphocytes, cell mediated immunity and antibody mediated immunity - I don’t understand it extensively and I don’t really know how much I need to know of it anyway! I would forever appreciate any help at all!!!
This is basically what I've remembered:
Think of the immune response as centered around helper T-cells (the starting point)
Helper T-cells have surface receptor proteins that are specific to an antigen, meaning they are able to detect a specific antigen
The way this detection can occur is by the helper T-cell recognising the antigen as it is displayed on MHCII molecules
MHCII molecules are glycoprotein molecules and are found on macrophages and B-cells, so either of these can hold the antigen on the surface of the MHCII molecule.
A macrophage can ingest an antigen and the fragments of the antigen are displayed on the MHCII molecule (can't think of a good analogy but maybe some jelly with the antigen fragments as sprinkles on top of jelly). So once the helper T-cell has the antigen brought by a B-cell or macrophage, its specific surface receptor protein will recognise the antigen and process it.
Then, the helper T-cell releases these 'signalling' chemicals called cytokines. The specific cytokine 'interleukin-2' basically stimulates B-cells to differentiate into PLASMA B-cells and MEMORY B-cells. T-cells also differentiate into CYTOTOXIC, MEMORY and SUPPRESSOR T-cells.
Plasma B-cells are important for the immune response as they can secrete antibodies, which specifically can inactivate or destroy the matching antigen.
Another mechanism comes into play for cytotoxic T-cells, which are MHCI molecules. These essentially mark infected body cells as targets for cytotoxic T-cells, which are ALSO specific to the antigen. The cytotoxic T-cells will move to find the infected cells, attach to them and release a chemical called 'perforin' which perforates the cell and causes it to lyse, which kills the infected cell.
Apart from this method of forming differentiated T and B cells, they can also be activated directly by antigens. Probably some stuff I missed, but if you know that in general you should be fine!
Translocation Down syndrome is sometimes hereditary apparently but i think in most cases it is not inherited (ur right). i think i would use another example like cystic fibrosis?
Thoughts on paper???
hi guys,
for the dotpoint "Process and analyse information from secondary sources to describe the effect of one name and described genetic mutation on human health", can i use SCID or colour-blindness ?
Hi guys~Hello, theyam.
Does anyone or has anyone, had the problem with your teacher going through numerous slides for theory for just a single dot point? And then turns out for exams, you only needed literally one slide worth of theory? How do I distinguish between what I need or don't need?
Thank you~~
From theyam
Hey Guys,
I was doing a dot point in maintaining a balance:
T.3.5 Distinguish between active and passive transport and relate these to processes occurring in the mammalian kidney
Im struggling to relate active and passive to the processes occurring in the mammalian kidney
it would be great if you guys could help
Hey Guys,
I was doing a dot point in maintaining a balance:
T.3.5 Distinguish between active and passive transport and relate these to processes occurring in the mammalian kidney
Im struggling to relate active and passive to the processes occurring in the mammalian kidney
it would be great if you guys could help
Hey guys,
I needed help answering this question about this dot point:
T.3.8 Define enantiostasis as the maintenance of metabolic and physiological functions in response to variations in the environment and discuss its importance to estuarine organisms in maintaining appropriate salt concentrations.
I have answered this dot point but however I don't think i have answered the 'discuss its importance to estuarine organisms.....'
It would be great, if you guys could help :)
Hi,
For the dotpoint:
T.4.2 Outline, using a simple model, the process by which DNA controls the production of polypeptides
what would be a good simple model to use to model protein synthesis?
Thanks, that helped alot.
I wasn't too sure if the dot point wanted me to draw a model as you said or link this process to an analogy.
Hey guysSo sex linked inheritance depends on the sex of the offspring. Since the X chromosome is longer than the Y chromosome, characteristics carried on the X chromosome may not be masked by the Y. Let's say the allele in question is recessive, if it were inherited by a girl she would need this allele on both chromosomes for it to be expressed in the phenotype. If the offspring were a boy, he would only need one copy of the allele, on his only X chromosome, for it to show. Therefore the inheritance of sex linked traits does not follow simple Mendelian ratios. I hope that made sense, if not just let me know and I'll attempt to explain in another way.
Could i get an explanation on why sex-linked genes don't produce simple mendelian ratios
Hey guysFor organisms under the XY sex determination system (e.g. humans or Drosophila melanogaster [fruit/ vinegar fly]), females have two X chromosomes (XX), whereas males only have one and fill the other with a Y chromosome (XY) when they inherit sex chromosomes. This means that the presence of the Y chromosome makes an organism male under this system. Each of these sex chromosomes has alleles - these are known as sex-linked alleles (sometimes referred to as X-linked alleles). This is usually denoted as a superscript letter beside a capital X or Y as appropriate, such as XwXw for a white eyed female, where 'w' is the white eye allele. Why it doesn't produce normal Mendellian ratios is because the progeny's sex will impact how much of the genetic info will be shown (but this isn't the end of the story, more on that below).
Could i get an explanation on why sex-linked genes don't produce simple mendelian ratios
So sex linked inheritance depends on the sex of the offspring. Since the X chromosome is longer than the Y chromosome, characteristics carried on the X chromosome may not be masked by the Y. Let's say the allele in question is recessive, if it were inherited by a girl she would need this allele on both chromosomes for it to be expressed in the phenotype. If the offspring were a boy, he would only need one copy of the allele, on his only X chromosome, for it to show. Therefore the inheritance of sex linked traits does not follow simple Mendelian ratios. I hope that made sense, if not just let me know and I'll attempt to explain in another way.
*AN suggestion: we should have some sort of drawing feature thing so that I could draw pedigrees and punnet squares to explain genetics Q's *
For organisms under the XY sex determination system (e.g. humans or Drosophila melanogaster [fruit/ vinegar fly]), females have two X chromosomes (XX), whereas males only have one and fill the other with a Y chromosome (XY) when they inherit sex chromosomes. This means that the presence of the Y chromosome makes an organism male under this system. Each of these sex chromosomes has alleles - these are known as sex-linked alleles (sometimes referred to as X-linked alleles). This is usually denoted as a superscript letter beside a capital X or Y as appropriate, such as XwXw for a white eyed female, where 'w' is the white eye allele. Why it doesn't produce normal Mendellian ratios is because the progeny's sex will impact how much of the genetic info will be shown (but this isn't the end of the story, more on that below).
What do I mean by this? For sex-linked traits with the XY system, male progeny are hemizygous (This basically means it only shows up one copy from its progeny.); they'll display whatever trait their mother gave them (they need an X chromosome to live) and automatically receive the Y chromosome their father had (because where else can they get a Y chromosome to become male?). The Y chromosome is often considered 'too small to have visible effect' ("gene-poor") and thus, Dad's genes don't show up in the male progeny's phenotype.
Mendellian ratios would show that both sexes of the progeny will be the same (female + males show Mum + Dad's info). Under sex-linked ratios, females will show both Mum + Dad's info (since they have 2 X chromosomes and inherit these equally from the parents), but males will only show Mum's (hemizygous). This difference causes the observed ratio differences.
The best example I can give you is on this link right here, which includes the research of Thomas Hunt Morgan on Drosophila melanogaster (the experiment that essentially discovered the existence of sex-linked alleles).
Some more helpful links: Sex-linked inheritance
See halfway down the page under "Inheritance of Sex Linked Traits"
NOTE: I got beaten by Potatohater, but I thought the links might be useful, so I'm posting anyway. Also, I know I explained it in a convoluted manner, but I hope it made sense. Since genetics is my major, I tend to have a more technical background.
Would the change in kangaroo teeth (from (ancient to modern) count as mac or mic evolution
If so, what would be the explanation
Would the change in kangaroo teeth (from (ancient to modern) count as mac or mic evolutionJust to add onto what Jess1113 said:
If so, what would be the explanation
Hey! This is probably a dumb question, but in our exams, are we ever allowed to talk in 1st/2nd person? Would "our body requires and wants to maintain a balance of water and salt, therefore, it passively reabsorbs and secretes water until we reach that balance." suffice? Or would that be illegible and we have to write "the human body requires and wants to maintain a balance of water and salt, therefore, it passively reabsorbs and secretes water until it reaches that balance."? I'm sorry if this is a dumb question I probably most likely know that we can't write in 1st/2nd person but I've gone blank. Thank you!!Sure you can write in 1st/2nd person so long as you are getting the point across clearly and concisely, so that 1st example is totally acceptable
what would be the reason for why maintaining body temeprature in mammals count as feedback system?
Hey! What are some examples of halophytes who use salt avoidance mechanisms rather than salt tolerance? Thank you!
Hi!
Red mangroves are adapted for salt exclusion, where root membranes in roots form a barrier against the passage of salt into xylem tissue.
Hope this helps :)
as for Mendel, "Plants that were self-fertilised were isolated from others (no accidental pollination using paper bag)."So I don’t do hsc haha but this just means that the plants are normally able to either self-fertilise OR be fertilised by other plants. In this test he only wanted them to be self-fertilised so he had to stop accidental pollination.
what does this mean? why would self fertilising plants fertilise other ones.. what
So I dont do hsc haha but this just means that the plants are normally able to either self-fertilise OR be fertilised by other plants. In this test he only wanted them to be self-fertilised so he had to stop accidental pollination.ohh makes sense!! thank you :)
ie. In the experiment they were self pollinated, but in the wild they didnt have to be
Can someone explain to me indepth speciation isolation? ThanksSo I guess you mean divergent evolution via isolation well basically it happens like this:
Does anyone have any tips for solving pedigree questions?The best way I found to tackle pedigree question is to rather than looking for a certain inheritance pattern I would try to prove all the patterns wrong.
I know the basics like the circle = female, square = male etc.
But I find trouble, for instance, in determining if a characteristic is dominant/recessive, or if a certain offspring is heterozygous/homozygous for a certain trait.
Thanks!
Hi
Could someone help me with this dot point: process information to construct a flow chart that shows that changes in DNA sequences can result in changes in cell activity
I tried searching it up but I didn't really understand it..
Thank you
Hii,1. Red kangaroo is enough, but just kangaroo is not. So yes, use your red kangaroos and, for ectotherms, red bellied black snakes, blue tounge lizards etc.
For the dot point "Compare responses of named ectothermic and endothermic organisms...", do we need to know the scientific name of each organism, or is 'Red Kangaroo' enough?
Also for "Develop a model of a feedback mechanism" is a flowchart of how the stimulus-response pathway assists temperature control in the body enough? I don't know if I'm studying less than I should be lol
Thank you!!
Hi,
So basically a mutation in DNA can change cell function in this way
Mutation -> mRNA codons are altered due to changed DNA -> tRNA codons altered due to changed mRNA -> potentially different amino acids in the chain -> different polypeptide -> different protein -> different cell function
I do hope that makes sense :)
Hello,Ahhh yes, so that diagram makes sense to me but I agree, it's not the best at explaining the concept when people havnt learnt it before. I'm glad I helped :)
Man every time I tried searching it up, I'd see the below flow charts and I was just like ._. So thank you so much for that explanation it really helped me!
Thank you
from theyam :)
1. Red kangaroo is enough, but just kangaroo is not. So yes, use your red kangaroos and, for ectotherms, red bellied black snakes, blue tounge lizards etc.
You have to be speciffic but not scientiffic
2. Yes that's perfect, a flow chart that explains how different tempratures trigger the stimulus-response pathway and what happens as a result, eg. Sweating, shivering etc. is exactly what they mean
Helllo could someone explain the reasoning to get the answer to this?Hey,
I think that at least B is definitely out as males can't be carriers, but how do I go on from there?
Hi all,
I'm having trouble with 9.4 Search for better health FQ3 where it asks to describe a named infectious disease in terms of cause, transmission etc. My class has chosen to do Malaria and I'm struggling to understand how the transmission of Malaria takes place. I was wondering if someone could lay it out in steps of what happens in the malaria transmission cycle (pretend you're explaining to a five-year-old)
Thanks in advance :)
Ok so mosquitoes suck people's blood
Hi i just wondering if they are any alternatives to the HSC Biology 2017 Q27a answer. The answer seems too simple.Ayy that was my year! Remind me, what was the question again?
Thanks :)
Hi i just wondering if they are any alternatives to the HSC Biology 2017 Q27a answer. The answer seems too simple.
Thanks :)
Hi i just wondering if they are any alternatives to the HSC Biology 2017 Q27a answer. The answer seems too simple.I would say just remember it is lignified (thus the wall on the marking criteria looks bigger) and that phloem is actually a lot smaller than xylem. It isn't obvious but xylem is actually bigger than phloem.
Thanks :)
I would say just remember it is lignified (thus the wall on the marking criteria looks bigger) and that phloem is actually a lot smaller than xylem. It isn't obvious but xylem is actually bigger than phloem.Thanks Mate :)
(http://ib.bioninja.com.au/_Media/root1_med.jpeg)
Question 27
In better responses, students were able to:
draw a scientific diagram of transverse sections of both xylem tissue and phloem tissue
demonstrate a distinguishing feature of xylem tissue and phloem tissue
so basically 1 mark for diagram. and 1 mark for 1 distinguishing feature. easy!.
Ahhh yes I remeber that one now - yeah I agree the marking criteria was really simple. For mine I showed that the phloem had companion cells and sieve plates where as the xylem has thick lignin wallsCheers ;D
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2011exams/pdf_doc/2011-hsc-exam-biology.pdf
hi how is the answer D? Thanks :)
I am a VCE kid, but I am sure I can aid you with this.OMG THANK YOU1!
My assumption is that you are perplexed over Q17 (the other questions with an answer 'D' look fairly straight-forward - correct me if I am wrong).
Now, we already know that the parents express the same phenotype, which implies that they have the have the same alleles for the gene concerned, immediately eliminating A and B.
Through examination of the offspring produced, we can clearly observe that three phenotypes result, which eliminates C, as only two possible phenotypes are displayed (BB = dominant phenotype, Bb = dominant phenotype, bb = recessive phenotype).
Thus, the answer is D (AA = Phenotype A, AB = codominant phenotype and BB = Phenotype B).
Hii!
Today in my The Search For Better Health exam there was a multiple choice question showing a picture of Pasteur's experiment being modelled, and there were 2 answers (the other 2 were silly answers) I'm confused about.
The diagram showed two flasks containing broth (one broken, one unbroken) being boiled and the question was 'How is this experiment valid' or something and the two answers were:
c) The use of a control
d) The heat used to boil the broth
I chose C but I don't know if I should have chosen D smh since IDEK if there was a control rip
Hey, like Phoenixx said, validity is when the independent variable (the variable changed) is the only changing variable in the experiment and all other factors are controlled, hence the experiment is measuring what it's supposed to.I would still say that C is the correct answer. Controlling variables is more a part of reliability not validity. An experiment can be valid but not reliable.
From what I can get from the answers, d sounds to me like a controlled variable itself but I'm not too sure; it depends on what the experiment is investigating specifically.
I would still say that C is the correct answer. Controlling variables is more a part of reliability not validity. An experiment can be valid but not reliable.
For example if your hypothesis is ‘chickens who eat more will lay larger eggs’ but your IV is the amount of water you give them, your experiment is not valid.
To be valid your experiment just needs to be capable of testing the hypothesis. So if you use the above hypothesis but your IV is the amount of food you feed them then it is a valid experiment.
However if you then give them different amounts of water it is not a reliable experiment as the results will change each time it is repeated (because there is not a set amount of water). It is still a valid experiment though because it is still testing the effect of food on egg size.
A control also implies that all other conditions are the same.
my understanding of reliability was also that when the experiment was repeated several times by a different experimenter, the same results would occur.Reliability means that you or another person could repeat the experiment and get the same results. The only thing that could change the results of the experiment are if you make a mistake, your method is not clear enough for someone else to follow or (most commonly) if there are variables that aren't controlled - hence why controlling variables is part of reliability.
can anybody help with this past hsc question?
Which of the following statements best describes the process of hybridisation frequently used in agriculture?
A The transfer of a gene from one species to another.
B The crossing of two genetically different strains of a species.
C The production of genetically identical offspring by cloning.
D The artificial selection and breeding of suitable offspring within a species.
I kinda see how all of these could be the answer so idkkkk :(
thankyou for any help :)
Hi could i please get help with understanding why the answer to the 2015 MCQ15 is C. Thank you, please find attached below a link to the paper: :D :D
https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-biology.pdf
Hi could i please get help with understanding why the answer to the 2015 MCQ15 is C. Thank you, please find attached below a link to the paper: :D :D
https://www.boardofstudies.nsw.edu.au/hsc_exams/2015/exams/2015-hsc-biology.pdf
Probably incomplete dominance so Ry is orange. I think they removed it from the syllabus anyways but to work it out just cross RR and YY to get RY then cross two RY to get RR, RY, RY, YY. These are just probablities and the experiment could be close enough to these ratios.Thanks for your help :D
Awesome question! I am VCEer, however, hopefully I can be of some help here.Thanks this helped a lot :D
This question is tricky because it requires very careful reading. Notice how it specifically intimates that 'the F2 results were...': it is referring to generation 2, not 1. Thus, the answer is C, as the ORIGINAL parents had genotypes RR and YY, thus producing offspring: RY, RY, RY, RY. These offspring then mated (RY x RY) to yield: RR, RY, RY, YY. Hence, we can see that the ratio of RR (red) : YY (yellow) is roughly equivalent (6:5) and the amount of RY (orange - incomplete dominance) should be approx double, which it is (11).
Hii!Yeah that's pretty much it, there are other substances but the question only asks for 2 so that's fine
In the 2 mark question 'Identify how the concentration of TWO substances will change as fluid moves through the proximal convoluted tubule', would it be correct to say that "As fluid passes through the proximal tubule, the fluid concentration of water will DECREASE as it passively is reabsorbed into blood by osmosis, and that the fluid concentration of amino acids will also DECREASE as it is re-absorbed into the blood through active transport"?
Thank you!
Yeah that's pretty much it, there are other substances but the question only asks for 2 so that's fine
Hii!
Today in my The Search For Better Health exam there was a multiple choice question showing a picture of Pasteur's experiment being modelled, and there were 2 answers (the other 2 were silly answers) I'm confused about.
The diagram showed two flasks containing broth (one broken, one unbroken) being boiled and the question was 'How is this experiment valid' or something and the two answers were:
c) The use of a control
d) The heat used to boil the broth
I chose C but I don't know if I should have chosen D smh since IDEK if there was a control rip
(C) is the correct answer but it's important to understand the full scope of what you are dealing with. Validity, in first hand investigations, is determined by how well you control all the variables that could possibly impact on the experiment. For example if you wanted to test the effect of 'variable Y' on 'variable Z', then A, B, C, .... X must be controlled. If any factor of A, B, C, ... X is NOT kept constant, then you are now NOT testing the effect of Y on Z - you'll actually be measuring the effect of Y and B on Z etc - not your aim, not valid.
The next thing is about the idea of a 'control' and a 'test' version - in this case the intact and broken glass. This is to with VALIDITY - not reliability. Here's why:
Our test is investigating the effect of 'Variable X - air exposure' on 'Variable Y - microbial growth in broth'. Our CONTROL is testing 'Variable Y - microbial growth in broth' WITHOUT changing 'Variable X - air exposure' so that we can compare the two later on. This is validity - testing your aim - being able to compare an unchanged with something you've changed (i.e. broken neck of flask).
Be careful not to say this has to do with reliability which, in the context of first hand investigations, is purely to do with the consistency and replicability of your results - not the nature or method of your experiment (which fall under validity always).
Hallo! Does anyone know the host response to influenza? I can't find it in my text book and all these scholarly articles on google aren't making much sense either...
thanks!!
Hello ! :)
While i was looking at some practice biology questions, i found one worth 4 marks that asks;
"Modern methods of disease control place more emphasis on prevention than on treatment"
DISCUSS this statement using atleast one named disease in your answer.
Just wondering how I would approach the question? Should i provide + / - for both prevention & treatment and relate it to a named disease, or is there a better way to respond.
Cheers.
Hello ! :)
While i was looking at some practice biology questions, i found one worth 4 marks that asks;
"Modern methods of disease control place more emphasis on prevention than on treatment"
DISCUSS this statement using atleast one named disease in your answer.
Just wondering how I would approach the question? Should i provide + / - for both prevention & treatment and relate it to a named disease, or is there a better way to respond.
Cheers.
Cheers for the reply, this was my response in the end;
Malaria is often approached using both methods of prevention and treatment, but like any other disease there are pros and cons to methods related to disease control and relying on one more than the other can often be counter productive.
Prevention:
• Insecticide treated nets have been proven to prevent malaria transmission quite effectivley, with an approximate 20% decrease in disese cases in children under 5, and a 50% decrease in malaria related episodes. Unfortunatley since the introduction of ITNs mosquitos are slowly developing immunity, rendering certain insecticides useless, also giving rise to difficulties of producing insecticides that are effective.
Treatment:
• Antimalarial drugs like chloroquine are very effective at treating malarial infections, chloroquine specifically prevents malaria parasites growing in RBCs. This limits the spread & severity if the disease inside the host.
• Just like certain preventitive measures (ITNs), developed immunity is a problem. Overtime the overuse of chloroquine and other drugs has given rise to drug resistant parasites, this had lead to increased prices for newer treatments and the serious danger of malarial parasites that are unable to be treated effectivley.
Any tips to maybe improve this response or is it fine how it is?
Yes, that's more than enough I reckon! The only thing I'd change is perhaps the length... exam time is precious so you wouldn't want to spend a lot of time writing that much on a 4 marker. (You might run out of writing space with your current length) You'd only need to cut a few words here and there, just to make it more succinct. But this isn't crucial, especially if you have small handwriting/write quickly. The importing thing is, you've attacked the question well and have addressed what you've needed to. :)
Hi there!
I was just wondering if anyone could think of an impact that the diphtheria vaccine has had on the environment?
So far, I can only think of social impacts :P
Thank you in advance ;)
Hey guys,
I was working on the genetics: code unbroken topic. For dihybrid crosses, does the question state if its linked or unlinked or do we need to figure it out. If so how would i figure out if its linked or unlinked?
Thanks in advance :)
Hi guys,
Could i please have some help in finding resources in regards to this question for an assignment - Outline the response by the host - Influenza.
Does the response mean *Immune response and the various factions of it.
Thank yooouuu!!
hey how do I find the complementary mRNA strand for TACCTTGTACCC
do I just write U instead of T so its AUGGAA or do I reverse the DNA strand?
The mRNA complement of TACCTTGTACCC would be:
CUGGAACAUGGG.
Hey guys,
I still dont seem to understand the benefits and the limitations of using quantitative and qualitative analysis. It would be great if someone can help.
thanks in advance :).
Had my biology first hand practical on modelling polypeptide synthesis BUT I'M MAD. We had to make TWO models (one normal, one mutation)
I didn't finish :((. There goes my good ranking from half-yearly.
I guess what annoys me is that it's not my lack of understanding the content, but rather my not being able to cut and glue the pieces of paper in time. Like you'd think a HSC assessment would have a more efficient way of modelling a process than a kindergarten-style cut and paste activity, but anyways.
what's the difference between management, prevention, control and treatment of disease? they seem to all have different meanings?
if anyone could help, I'd be really grateful
Hi...You can just write DNA and RNA; the syllabus even shortens it as well. :)
For well-known substances like DNA and RNA, are we allowed to write their shorthand names in the exam?
Or do we actually have to write 'deoxyribose nucleic acid' etc?
You can just write DNA and RNA; the syllabus even shortens it as well. :)
How do you study for the hsc biology trials that are comming up soon?
can anyone please explain how the dihybrid pea experiment is shown on punnet squares? :/ thank youI won't provide the answer, as you will not learn anything, but I'll explain that a dihybrid pea is heterozygous for two traits.
B-cell
lymphocyte produced and matured in the bone marrow (thus B cell)
humoral response: antibody producers. They respond to antigens, which are foreign markers or molecules.
.antibodies are like things that stick on the surface of antigens(foreign particles) and form a antigen-antibody complex which helps disable it and allow phagocytes to engulf it.
T cells
lymphocyte that comes from bone marrow but matures in thymus gland (thus T cell)
cell-mediated response: They respond to i guess to infected cells which can present to cytotoxic t-cells. SO basically the difference is T-cells respond to cells which are infected and present fragments of the invader to t-cells and B-cells respond to antigens which are like foreign substances.
T cells kill cells. Unlike B-cells, they specifically attack other cells by inserting chemicals into them and killing the cell whereas B-cells just produce antibodies and attack the foreign fragments/substances from afar.
I'm not really that sure either but i'm pretty sure T-cells are intracellular and kill the invader that is inside the cell whilst B-cells are extracellular and kill what is not inside a cell.
Hey guys
Im a bit confused, for the interaction between T and B cells, do we just need to know the antibody mediated immunity?
Hii,
For the dot point 'Discuss evidence for the mutagenic nature of radiation', since the directive term is a "Discuss", what points against evidence for the mutagenic nature of radiation would we use? Or do we not need to have points for and against?
Thank you!!
The NESA website () directs students to "Identify issues and provide points for and/or against" for discuss. Therefore, it is not necessary to talk about issues against. Besides, with this dot point you simply have to find various evidence of the ways that the exposure to radiation has the potential to cause mutation. For example, victims of the Hiroshima and Nagasaki nuclear bomb show birth defect in offsprings.
Hope that helps!
Hii,
I'm confused over a 5 mark past trial question,
"Use the Darwin/Wallace theory of 'natural selection' to explain the increasing numbers of antibiotic-resistant bacteria AND how this knowledge can be used to reverse this resistance trend."
I understand the first half of the question, as it is just linking the way in which the theory of evolution is responsible for antibiotic resistance, but I don't understand how that knowledge can be used to reverse resistance. I thought antibiotic-resistance could be SLOWED through the use of narrow-spectrum antibiotics, finishing the course, etc, but reversed?
Any help would be appreciated!
Hi,
I'm struggling with the meiosis diagram-type questions where it asks to find the possible genotypes.
For instance these HSC questions
2002 Q22
2007 Q22d
After looking at sample answers, I can work backwards and see how it was answered, but I don't understand why it was done that way.
Could someone please explain the thought process on how to answer the above questions?
Thanks ;D
So for the 2002 paper with question 22, they've asked to construct a table listing possible genotypes that could be produced after meiosis with random segregation has occurred and the expected frequency of each genotype.
The cell features 3 pairs of homologous chromosomes. In meiosis this will divide into haploid cells like in the diagram if attached (see attachment). Note that a haploid cell has 1 chromatid of from each of the 3 homologous chromosomes pairs. So to find all the possible genotypes, we basically have to find all the possible combinations where one chromatid can be E or E, another can be B or b and the last one can be G or g
The possible combinations we can get are:
EBG
EBg
EbG
Ebg
As there are 4 of them and they all have an equal chance of being the genotype, they all have an expected frequency of 25%
For the 2007 paper, question 22d, make sure you:
1) show the difference between genes and alleles by defining them both
2) make reference to the diagram as well
A sample answer could be:SpoilerGenes are sections of DNA that code for the production of a specific polypeptide (e.g the section of DNA that codes for B or b). Whereas, alleles are variations of genes (e.g. B and b are variations of a gene)
Hope this helps :)
Thanks for your answer! For the 2007 one I was meant to write b) though, sorry.
is it possible to learn the whole syllabus in 2 weeks and get a good mark and how??
what are the parts of the ear involved in
a) transmission of sound waves
b) amplification of sound waves
c) Reception of sound waves
do helper T cels help killer T cells identify the antibodyHey, amelia20181.
do helper T cels help killer T cells identify the antibody
what does a renal dialysis machine actually do?
Can someone please explain this dot point,
analyse information from secondary sources to outline the evidence that led to Beadle and Tatum’s ‘one gene – one protein’ hypothesis and to explain why this was altered to the ‘one gene – one polypeptide’ hypothesis
for b can you say
ensure the temperature is kept constant throughout the experiment
if there is a decrease in blood pressure would you need aldosterone to increase salt reabsorption or antidiuretic hormone
around how much should you write for a 7 marker
if you just write pelvis and not renal pelvis when labelling a diagram of a kidney would you get a mark
if the ratio of urine concentration to plasma is 4:1 would the organism be more suited to a desert environment
For the syllabus dotpoint:
• LT: explain how one of the following strategies has controlled and/or prevented disease:
- public health programs
- pesticides
- genetic engineering to produce disease-resistant plants and animals
Can we still be asked about any of the 3 in an exam question??
would an organism with a 14:1 ratio be more suited to a desert environment than the organism with 4:1
can you say that a lizard lies in the shade so that its body temperature is cooler than the air
would respiratory tract infections or diarrhoeal diseases be caused by untreated drinking water
can you say that something is negative feedback because it returns to the stable state
when you are evaluating a statement should you first say the statement is correct
would you get a mark if you say bees can see in infrared
would you get a mark if you say humans can see in the visible spectrum but get the range wrong
how would you write an epidemiological study
Thanks KT Nyunt!
Hi everyone, i have been stirring on this syllabus dot point in the Biology option of Communication - Define the term threshold and explain why not all stimuli generate an action potential. ...... I am unsure what the last part of the question means "explain why not all stimuli generate an action potential". Any helps as soon as possible would be of great appreciation.
Thanks, Mate2425.
A neurone and a neuron are the same thing but why is there different spelling
Can you say Down syndrome is caused by a mutation
Hii,Obviously I don’t do HSC, so I’m not exactly sure what you need to know but we do a bit about plasmids in VCE.
I know not many schools do the Genetics option but unfortunately my school does, and my biology teacher has been away and I'm LOST. I'm not sure if anybody here has done it but if so, could somebody please help me understand the dotpoint 'outline the procedure to produce recombinant DNA'. From what I initially understood, this was a simple process just like in Blueprint of Life as recombinant DNA refers to combining DNA from two different species, eg the process of transgenesis which I understand. But for this specific dot point, all the information in textbooks is about separating DNA, inserting it into a plasmid and then cloning it in a bacterium and I'm confused. Where does the other species' DNA come from? Or is the plasmid the other species? Genetics is really hard :(
Obviously I don’t do HSC, so I’m not exactly sure what you need to know but we do a bit about plasmids in VCE.
So the foreign DNA is normally something that is useful to humans - for example the insulin gene.
Both it and the plasmid (from bacteria) are cut with the same restriction enzyme, leaving them with conplimentary sticky ends. They are then mixed together and some of the foreign genes will bind to the plasmid (some of the plasmids will also just rejoin without the new gene). These recombinant plasmids are then put into bacteria (plasmids are naturally exchanged between similar bacteria).
The bacteria that have the recombinant plasmid then reproduce and you end up with lots of bacteria producing insulin (or whatever the gene is for) which can then be extracted and used.
From 2015 HSC
Could someone please explain why the answer is B lol
Heyyyyy guys
I was wondering if someone can explain T cells and B cells to me i am completely lost on them
;D
can someone please explain this
Thanks!
can you explain why the answer for this question is b
hey, this is a question form 2015 hsc biology communciation section. just wondering , can someone help me out with it? im kind of confused even tho i know its supposed to be a "general/easy" question :'( :'(
explain why some stimuli would not generate an action potential in a neurone?
thanks so much
Are prions cells and can they reproduce outside a host cell
Hi...Random segregation means that homologous chromosomes are randomly placed into the daughter cells. Independent assortment means that which of a homologous chromosome is placed into a daughter cell has no effect on which copy of a different chromosome is placed into the same daughter cell.
What is the difference between independent assortment and random segregation? I always get confused between these two...
HEY GUYS! TO ANYONE DOING MALARIA AS AN INFECTIOUS DISEASE, WHAT IS THE HOST RESPONSE? I'VE DUG THROUGH THE INTERNET HIGH AND LOW BUT KEEP ENDING UP IN COMPLEX REPORTS AND ARTICLES THAT ARE REALLY IN DEPTH AND WAY BEYOND THE BIO SYLLABUS. ANY HELP WOULD BE APPRECIATED! :) :)
Hey,
In regards to 'evaluate' and 'assess' questions for Biology are we allowed to be half half...
Like for English and Legal, often I'll say "somewhat effectiveness" or "mostly effective" however when I've read aloud bio answers in class despite me giving both positive and negative things whenever I say "somewhat" my teacher says we have to choose one or the other.
I just wanted to check if this is actually the case or in the HSC can we be on the fence?
Thank you :)
Hi...
Let's take a look at the NESA definitions for each:
Evaluate: Make a judgement based on criteria; determine the value of.
Assess: Make a judgement of value, quality, outcomes, results or size.
So it is very clear that you need to make a judgement, and you techniquely have, by saying it is 'somewhat effective'. However, this choice of words can sometimes come across as too much like a discuss question, and you cannot really show a clear judgement and still sit at 50/50. Thus, it is always best to pick one side. You can still show in minor ways how they are / aren't effective (this shows you have thought about your response), but really emphasise which side you are taking - especially at the start and end of your answer.
Hope this helps. :)
HOW THE HECK DO YOU STUDY EFFECTIVELY FOR BIO???
It's too overwhelming to know where to start :-[
Hi there!
Just had a quick question regarding the Biotechnology Syllabus - for the following dot points do we only choose one of the suggested or was it providing an example for EACH of the ones they've listed? (bit of a stupid question, but the wording of the dot point just hit me hard haha)
• describe one example from the following applications of aquaculture:
ー production of a pharmaceutical from algae
ー farming of a marine animal
• describe one example from the following applications of animal or plant biotechnology:
ー production of monoclonal antibodies
ー recombinant vaccines to combat virulent animal diseases
• describe one example from the following applications of biotechnology in medicine:
ー tissue engineering using skin transplantation as an example
ー gene delivery by nasal sprays
ー production of a synthetic hormone, such as insulin
Thank you in advance :) !
When blood pressure drops, the body responds by:
A) releasing ADH to increase reabsorption of water
B) releasing ADH to increase uptake of salts
C) releasing aldosterone to increase reabsorption of water
D) releasing aldosterone to increase uptake of salts
Why is the answer for this question A and not d
When blood pressure drops, the body responds by:
A) releasing ADH to increase reabsorption of water
B) releasing ADH to increase uptake of salts
C) releasing aldosterone to increase reabsorption of water
D) releasing aldosterone to increase uptake of salts
Why is the answer for this question A and not d
Hey guys was wondering if someone could please give me a thorough explanation to HSC 2017 MCQ9. and MC.Q20.
https://educationstandards.nsw.edu.au/wps/wcm/connect/fc23024b-f91e-468c-90b5-8d522b8d2dbf/2017-hsc-biology.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-fc23024b-f91e-468c-90b5-8d522b8d2dbf-m0Qr1Ki
Many thanks ;)
http://www.k6.boardofstudies.nsw.edu.au/wps/wcm/connect/88b8b597-9f96-46d5-a389-0a86145f97bb/biology-hsc-exam-2008.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-88b8b597-9f96-46d5-a389-0a86145f97bb-lGcvlf6D is wrong because there is nothing called a male "carrier" they are either affected on unaffected for sex linked diseases .
2008 Q15: i need help with this punnett square. I understand how to narrow it down to C and D since the male gets the X-chromosome from the mother but i don't know why D is wrong.
Can someone please explain what Sutton and Boveri did?
hey guys
in regards to SFBH, for the gene expression & maintenance of health and repair of body tissue dotpoint, is there an easier/simpler example other than the BRCA1 gene & PTEN gene example?
thanks in advance!!
Hi...
Not sure what example you are referring to, but for this dotpoint, I generally talk about the ramifications of the mutations of different genes involved with the cell cycle. Some examples:
- Mutation of p53 gene --> cell cycle does not pause to repair DNA --> --> can lead to tumours (50% of cancer cases involve a mutation of p53).
- Mutation of DNA repair genes --> DNA damage accumulates --> production of incomplete proteins --> impaired functioning of cells.
- Mutation of tumour supressor genes or proto-oncogenes --> uncontrolled cell division --> tumour.
I have seen examples talking about the gene for cystic fibrosis (CFTR), but I think the above ones are easier to use. Hope this helps! :)
Could someone explain the role of Antibodies?
I thought it was like a targeting system that enables white blood cells to see which cells to kill
Do antibodies kill the pathogen?
Hey, so what do we do if we need more writing space/paper for the short response Q and not option Q?You ask one of the exam supervisors for another spare booklet to re-write or for more writing space for that particular question. They give you a booklet, write your student number, centre number and the question you are answering in that box which states which question you are answering.
What if you write below the lines of 6 lines for example and there so space can’t you just write on the black space provided ??
What if you write below the lines of 6 lines for example and there so space can’t you just write on the black space provided ??
OMG I was wondering the exact same thing!yes you are allowed to use the blank space. I know this isn't for all subjects but yes, I have confirmation from the HSC4ME UTS live chat biology marker that you can.
Producing transgenic species:
increases or decreases genetic diversity?
(I asked my teacher this, she didn't know the answer. :o)
Decreases. Let me know your thoughts on why you think this is :)
Well, I originally thought that it would create new combination of genes (hence the increase)...
But when producing transgenic species, they make heaps of copies of the same gene to insert - which makes one allele more common than the others. I'm not sure if this is the correct reasoning for why genetic diversity decreases, or just something else I have observed?
Well, I originally thought that it would create new combination of genes (hence the increase)...
But when producing transgenic species, they make heaps of copies of the same gene to insert - which makes one allele more common than the others. I'm not sure if this is the correct reasoning for why genetic diversity decreases, or just something else I have observed?
Hey, So I too was so confused about this. I think this is right based on questions I've seen and it sorta makes sense with like the biological principles we learn.
From what I've gathered initially it increases genetic diversity as new genes are being introduced. However over time these favourable characteristics will survive and hence eventually decrease genetic diversity.
I saw like a 5 marker on this saying short and long term effects I think and also a mc with a table and it was like short term long term and had transgenic and something else like say cloning and you had to pick the correct row. Sorry I don't remember where the question was from.
Hope this helps.
Good on you both for thinking through this question. By and large I think you've got the right idea.
My reason for saying decrease was the practicalities of transgenic organisms. We tend to use transgenic organisms to replace organic organisms. For instance, we foritifed rice with vitamin A making genes and then planted this rice instead of native rices. The effect of this is to decrease the diversity in rice crops, even though we've technically added a gene to the gene pool. This is one of the most pressing concerns with the use of GMOs, which despite what some groups might say, are safe but do decrease diversity and therefore potentially increase the risk of catastrophic famines if a change in the environment prevails to kill that crop (less diversity means less capacity to deal with the change).
Yeah I 100% agree, just based on HSC questions I've seen I've noticed a few do say short term increase which is tricky as you pointed out the aim is to decrease the diversity. I think it's cause they want you to use your knowledge of natural selection and evolution.
Thank you!
. and for the multiple choice I'm really confused because my punnet square showed that only 1 child(25%) should get the disease but there is already one child. so how can the answer be b?
thank you!!
hey can someone please tell me how to approach the long response question and what I should include.?looking at it i'm as stumped as you. but looking at the sample answer:
thank you!!
hey can someone please tell me how to approach the long response question and what I should include. and for the multiple choice I'm really confused because my punnet square showed that only 1 child(25%) should get the disease but there is already one child. so how can the answer be b?
thank you!!
hELLOO
I NEED URGENT HELP
DIFFERENCE BETWEEN CELL DIFFERENTIATION AND CELL SPECIALISATION
I READ THROUGH SO MANY NOTES AND EACH IS DIFFERENT TO THE PREVIOUS ONE
THANK YOUU
But they're so similar tbh i dont think they'd even ask for a difference (i hope)
Hi,Proteins are made of one or more polypeptides. So polypeptide synthesis is the process of joining amino acids together via peptide bonds. Then these polypeptides may join or fold to form proteins. For example, Enzymes are globular proteins and can be made of many polypeptides folded together.
Could someone please explain the difference between protein synthesis and polypeptide synthesis??
Thanks!!
Does direct contact include blood transfusion? Say Malaria, if a blood transfusion containing the malaria parasite, that would be direct contact? cause blood is a bodily fluid. Am I right?As far as my quick research goes, direct contact is specifically person-to-person, while indirect contact can include transmission by vectors (like mosquitos). Therefore, blood transfusions would be considered via. indirect contact.
The first dot point of the syllabus mentions an 'including but not limited to'... what does this refer to? The organism or type of reproduction. And what is an example for an additional?
● explain the mechanisms of reproduction that ensure the continuity of a species, by analysing sexual and asexual methods of reproduction in a variety of organisms, including but not limited to:
– animals: advantages of external and internal fertilisation
– plants: asexual and sexual reproduction
– fungi: budding, spores
– bacteria: binary fission (ACSBL075)
– protists: binary fission, budding
thanks
Can someone please attach the new HSC bio syllabus because I cannot find it, thank you.
Hello guy so i got holiday homework and this is one of the questions, do you reckon you can give me a hand with this protien syntheis question it is worth 6 marks. I would greatly appreciate your kindness and willingness to help me like me to learn and become better people. Much love
EB
I was able to find it here: https://educationstandards.nsw.edu.au/wps/wcm/connect/657d2611-c201-49ce-a18e-ef0f786a5de0/biology-stage-6-syllabus-2017.pdf?MOD=AJPERES&CVID=
I know the syllabus says it's from 2017, but from what I've seen, it's very similar (if not the same) to what I've already been learning in my Prelim course and my one term of HSC from last year.
I found the syllabus PDF from https://educationstandards.nsw.edu.au/wps/portal/nesa/11-12/stage-6-learning-areas/stage-6-science/biology-2017. There's also a Word version of this available. Unfortunately, I can't attach the syllabus because it's a little too large. Please access one of the links and download the PDF/Word version of the syllabus if you want a copy!
Hope this helps!
Hi, it appears that you haven't written the question yet. Did you try to attach a photo? :)
Hello everyone :)
My biology teacher has been getting us to learn a lot about the history of Mendel's experiments with his garden peas and the steps he took to obtain his results (F1- monohybrid cross produced offspring that took on the characteristics/phenotype of only one parent, F2 produced offspring in ratio 3:1 etc.) In terms of the new syllabus, how significant do you think the context of Mendel's experiments are to the syllabus content because I feel as though I am wasting time learning content that potentially may not be tested in the HSC exam for the new curriculum.
Do you guys have any opinions?
Thank you and have a good night :)) ;D
I think it's always safe to listen to your teacher seeing that they're marking you on your internal exams thus determining 50% of your HSC mark. Also understanding Mendel's work does help us understand the principles of dominant and recessive genes and how alleles are passed on to offspring which are the foundations of Module 5: Heredity. So in my opinion, it's worth learning it. But I'm also aware that the new syllabus is removing a lot of historical aspects. So understand his experiment and why he got particular results, but learning why his work wasn't immediately recognised as significant (which was in the old syllabus) may not be as critical in the new syllabus. Keep in mind, even if his name is not in the syllabus anymore, a question can still be asked about him in the HSC as his work is very relevant to the heredity module.
Hope this helps :)
I attended the biology lecture at uts today.
I was wondering if someone can tell me where I can find the powerpoints from these lectures.
If someone can direct me then that would be awesome ;D
I attended the biology lecture at uts today.They'll be in the notes section as owlbird said, but they're generally not uploaded until the end of the lecture series. Assuming it's the same as for vic, you'll probably also get an email with the link and the link will be posted on ANs social media.
I was wondering if someone can tell me where I can find the powerpoints from these lectures.
If someone can direct me then that would be awesome ;D
Hi guys,
This is a bit of a general question but I am currently finishing off my bio depth study, and am approx. 500 words over the word count...
Does anyone have advice on things I could do to cut it down (I have already removed almost all of the adjectives)? I'm a bit concerned that cutting down will mean losing content...
Thanks!!
Hi, I graduated last year but I've had a look at the new Biology syllabus and I'm a little confused: are there option topics anymore (like communication or genetics in the old syllabus) or does everyone have to do the same 4 modules?
Is this the same for other sciences like chemistry?
Hello!
Can anyone provide some tips on writing an introduction and discussion for a depth study - what to include etc?
Thanks!
Hi,
I'm in year 11 doing the Preliminary Course and was just wondering what the best resources or advice there is out there/ suggestions. Anything is much appreciated!
Kind Regards,
Coolmate :D
At the moment I have this as my response and not sure if it is correct:
Is a control used in this experiment? If so, identify it and explain why it was used.
The control in this experiment is the broth. A constant amount of broth is used, and boiled for the same amount of time. Since the aim of this experiment is to test whether nutrient broth could spontaneously generate microbial life, the broth was boiled to sterilize, so it it contained no living microbes. By having a sterile broth in both flasks it was impossible for germs to spontaneously generate, hence, it could be determined that organisms carried in the air were able to enter the straight neck flask and contaminate broth and cause it to decay.
Hi :)!
I was wondering if someone could explain what the control is in Pasteur's experiment??
Is it the flask with the straight neck or the sterilized broth??
At the moment I have this as my response and not sure if it is correct:
Is a control used in this experiment? If so, identify it and explain why it was used.
The control in this experiment is the broth. A constant amount of broth is used, and boiled for the same amount of time. Since the aim of this experiment is to test whether nutrient broth could spontaneously generate microbial life, the broth was boiled to sterilize, so it it contained no living microbes. By having a sterile broth in both flasks it was impossible for germs to spontaneously generate, hence, it could be determined that organisms carried in the air were able to enter the straight neck flask and contaminate broth and cause it to decay.
Thanks in advance!!
Hope that helps!
Q. 4. Apply your understanding of evolution by natural selection to explain how plants and animals have developed such complex and successful defences against pathogens.
Hi :)!
I was wondering if someone could explain what the control is in Pasteur's experiment??
Is it the flask with the straight neck or the sterilized broth??
At the moment I have this as my response and not sure if it is correct:
Is a control used in this experiment? If so, identify it and explain why it was used.
The control in this experiment is the broth. A constant amount of broth is used, and boiled for the same amount of time. Since the aim of this experiment is to test whether nutrient broth could spontaneously generate microbial life, the broth was boiled to sterilize, so it it contained no living microbes. By having a sterile broth in both flasks it was impossible for germs to spontaneously generate, hence, it could be determined that organisms carried in the air were able to enter the straight neck flask and contaminate broth and cause it to decay.
Thanks in advance!!
Hey. For pedigrees, how do we know if a trait is dominate or recessive or whether it is X-linked dominant or X-linked recessive?If it’s dominant, it would be represented by a capital letter, if recessive a lower case. I’m not too sure about the other two.
Hey. For pedigrees, how do we know if a trait is dominate or recessive or whether it is X-linked dominant or X-linked recessive?
If it’s dominant, it would be represented by a capital letter, if recessive a lower case. I’m not too sure about the other two.
Hi Coolmate!
This response is quite a while after you first posted your question, but I hope it can still help you.
Firstly, get on top of your notes + key concepts ASAP!! Biology is quite content heavy so if you can grasp the concepts and practice them from the very start until the very end, you will find it very useful. Make sure you ask your teacher to go over any concepts you don't understand, and pay attention to any feedback they give you on assignments/exams.
I found the ATAR Notes biology course notes super helpful, and if you can, try and attend some ATAR Notes biology lectures because they recap the previous topics, and prepare you for what's coming up - this definitely gives you an advantage over all your peers who haven't attended!! You should also look at the previous lecture slides and use them to your advantage when making study notes!!
Finally, find out what study techniques work for you. It's better to do this while you are in year 11, so you can set yourself up well for year 12.
Best of luck and have fun!!
:)
Would someone be able to say in order from smallest to largest the size of different pathogens
also does anyone have any good mnemonics for remembering the pathogens that order?
thanks!
Hi,
Unfortunately I don't have any memorable mnemonics but in order from smallest to largest the pathogens are:
Prion
Virus
Bacteria
Protozoa
Fungi
Macroparasite
Hope this helps!
;D
Q. In domestic cats, when exploring crosses involving two fur colours (black and orange) the following observation is always made: A cross between an orange female and black male produces orange males and tortoiseshell shell female offspring. (Tortoiseshell is a mix of orange and black fur)
The most likely explanation for this is that the alleles for fur colour demonstrate?
A)sex- linkage
B)co-dominance
C)incomplete dominance
D) sex linkage and co - dominance
Guys for this question the answer is D but can someone explain why? I tried doing a punnett square with the female being heterozygous and the male homozygous recessive but it didnt seem to work...
HSC BIOLOGY Q&A THREADTo go straight to posts for the new syllabus, click here.
What is this thread for?
If you have general questions about the HSC Biology course or how to improve in certain areas, this is the place to ask! 👌
Hey dude! do you know how many treatments you should know for your chosen non- infectious disease in module 8?
Who can/will answer questions?
Everyone is welcome to contribute; even if you're unsure of yourself, providing different perspectives is incredibly valuable.
Please don't be dissuaded by the fact that you haven't finished Year 12, or didn't score as highly as others, or your advice contradicts something else you've seen on this thread, or whatever; none of this disqualifies you from helping others. And if you're worried you do have some sort of misconception, put it out there and someone else can clarify and modify your understanding!
There'll be a whole bunch of other high-scoring students with their own wealths of wisdom to share with you. So you may even get multiple answers from different people offering their insights - very cool.
To ask a question or make a post, you will first need an ATAR Notes account. You probably already have one, but if you don't, it takes about four seconds to sign up - and completely free!OTHER BIOLOGY RESOURCESCLICK ME!* Free Biology notes
* HSC Biology Question Thread
* How to Get a Band 6 in HSC Biology
* HSC Biology - How to Get a Band 6
* HSC BIO GUIDE: BLUEPRINT OF LIFE
* HSC BIO GUIDE: THE SEARCH FOR BETTER HEALTH
* Long Responses in HSC Biology
* HSC Biology: How to Ace the 8 Marker Questions
* How to Go About Studying for Any ScienceOriginal post.Hello Bio Students, Whilst I may not be one of the ATARNotes legends, I noticed that there wasn't one of these threads in our section of the forums so I thought I'd start one up.
Basically this is a place where any of the Biology Students or Lecturers to come and place any questions that they need help with, or answered questions that you want marked or feedback on, or even just questions on the general concepts in Biology that you may need help with.
For me, I've done the core modules for Biology and I've gotten through a little bit of the Communications Option so feel free to ask me any questions regarding that. I'm currently first in my Biology class so I feel as though I can help some other people out, but feel free to prove me wrong and help others out with any questions. Looking forward to seeing these questions too
Let's get this thread rolling
Skidous
Hey, would anyone be able to explain to me metaphase I/anaphase I in meiosis - or more specifically just how homologous chromosomes work. I know that when they line up, it's the paternal and maternal copy of the same chromosome lining up, but I don't understand how this fits in with the whole scheme of things because fertilisation happens after this point, right? So how does one cell that is preparing for fertilisation already have the genetic material from both parents?
Thanks!
Hi! I just had a question about the ATAR Notes Biology Topic Tests. For the Reproduction Test 1 Q7, could I make a table on sexual and asexual reproduction rather than internal/external fertilisation?
Thank you!!
Hi! This is a really good question!
Homologous chromosomes, as you correctly said, are one copy of each chromosome from the mother, and one copy of each chromosome from the father. They are similar in length but may have different alleles.
In females, meiosis occurs before birth, and in males in continually occurs after puberty. In both these cases, the male and the female already have the genetic material from their parents.
To make it a bit simpler, let's call the parents generation 1, and the child generation 2
Generation 1 are adults therefore they have all their genetic material
Generation 2 is created as a result of reproduction by generation 1. This means generation 2 has all their genetic material from their parents.
As generation 2 develops, their cells undergo meiosis giving them (generation 2) the capacity to create generation 3 once their bodies have matured to be able to do so as they now have their own gametes that can be fertilised.
It's quite a difficult concept to understand, but when you said, "how does one cell that is preparing for fertilisation already have the genetic material from both parents?" this cell 'preparing for fertilisation' is already inside a living organism created by reproduction, therefore they already have the genetic information from their parent.
Let me know if this still doesn't make sense!!
:)
Hi does anyone have any info on a viral plant response all I am able to find is fungal! Would really appreciate some help. I can find the name and the pathogen but not the actual response if that makes sense :P :P
Hi there!
This is some information on viral pathogens and the response of an Australian plant from easyhsc.com.au
Hope this helps!
Turnip Mosaic Virus
Causative pathogen:
Turnip Mosaic Virus (TuMV), a potyvirus belonging to the family Potyviridae.
Host Range:
Almost all Brassica species and other plants including:
B. oleracea
B. campestris
B. juncea
B. pekinensis
Latuca sativa
Nasturtium officinale
Raphanus sativus
Symptoms:
Chlorotic spots on inoculated leaves
Mottling followed by systemic vein clearing
Mosaic and/or necrosis
Leaf distortion
Stunting
Management:
Exclusion or avoidance – quarantine, growing crops in regions where the virus seldom occurs or during periods when the virus or its vector are at a low activity level and using virus-free seedling transplants.
Reduction in virus spreading sources – controlling weeds and other virus hosts and insect vectors, destroying old crops promptly, separating new crops from maturing crops, and avoiding overlapping crops, particularly year-round cropping.
Protection of the host plant – planting virus-resistant varieties, using barrier crops to reduce insect vector activity in the crop, using insecticides to protect plants, and using highly reflective mulches and oil sprays to deter insects.
Hey thanks for that! yeah i did see that website except I'm pretty sure we need the host response. so instead of quarantine and stuff what does the actual plant do to kill the antigen? But thankyou again for the info- it is hard to find
I need someone to explain to me why this pedigree chart is autosomal recessive and not sex-linked.
This is a question from Excel Success One and the answers say that for the condition to be sex-linked, the unrelated females in the second generation must be carriers. I used this reason in my justification, so I'm a bit confused. Sex-linked inheritance can occur even in non-blood-related individuals, right? Or must the inheritance of the 'disorder' be strictly between blood-related individuals?
Hi everyone,
Considering the following question
("increased scientific understanding of processes of reproduction has allowed for rapid growth of the agricultural industry over the past few decades." Evaluate this statement with reference to at least specific scientific techniques.)
When we are asked to evaluate, isn't like give positives and negatives and a judgement? Because the way I structured my answer is :
Tech 1+definition+ advantages (2)
Tech 2+definition+ advantages (2)
Common disadvantage of the 2 techs
Judgement.
However, the answer only talks about the advantages without any disadvantages. So can someone please explain why? And which way is better? Thanks
Hi Hawraa!
The way you answered the question is definitely correct. If the question asks you to evaluate, you should definitely make a judgement, but to be able to make a judgement you need to give reasons for and against!
The only reason I could think of, for why they didn't provide disadvantages, would possibly be because of the mark allocation??
To be safe in the HSC, definitely provide reasons for an against and specifically state the reasons for your judgement/decision.
Good luck tomorrow!!
;D
Cmiiw but in the syllabus, you only need to know an Australian plant response to either a fungus or virus (that's what my teacher said). Since you already have one for fungus, should be all good. :)
hey! just wanted to know is dolly a transgenic organism? if the question asks for transgenic organism can i talk about somatic cell nuclear transfer? thanks
Hi,
Can someone please help me with this question.
How could a change in a polypeptide effect cell activity?
Is it correct to say that since polypeptides are folded and modified to produce proteins, a change in polypeptide would result in a dysfunctional protein. This would impact cell activity such as for example if the affected polypeptide encoded for a protein functioning as an enzyme to regulate cellular processes such as DNA replication, it could prevent the process from occurring thus preventing it from copying and passing the genetic material to daughter cells, or if the polypeptide is encoding for a protein functioning as an antibody it would affect the immune system ability to recognise foreign particles and impair its ability to initiate an immune response.
Which one is a better example? (by the way, the question worths 2 marks.) thanks.
Hi!
I think the best answer is to say that a change in a polypeptide chain (such as alterations to the amino acid sequence) could affect/alter/damage the protein produced, hence impacting its functional ability. You could then use your example, "This would impact cell activity, as if the polypeptide is encoding for a protein functioning as an antibody" it would affect the ability of the antibody to bind to and neutralise a specific antigen, hence compromising the immune response.immune system ability to recognise foreign particles and impair its ability to initiate an immune response.
As this question is only worth two marks, I think it's enough just to give a basic definition / overview of what would happen if a change occurred, and one solid example.
Hope this helps!
:)
Hi there,
Dolly was a clone produced by whole organism cloning, which occurs through somatic cell nuclear transfer.
With transgenic organisms or transgenesis, it does not include somatic cell nuclear transfer. It is the introduction of DNA from different organism into another organism to exhibit a particular trait and pass it to offsprings. Such as pest resistent crops. Hope this answers your question.
Why are white blood cells bigger and fewer in number compared to red blood cellsHey Annasimon,
Why does a small cube have a higher surface area to volume ratioThis video should help...
I can’t see the video . It says playback error...Try this: https://youtu.be/uu9eHX6Tu8Q
Ok . Also why does the Y chromosome not undergo crossing overHomologous chromosomes are a pair of chromosomes with the same genes, one originating from the mother and the other from the father in sexual reproduction (And yes, they have different of the same genes).
And would the definition of homologous chromosomes be chromosomes that have the exact same genes but different versions of the gene-alleles
Thanks!!
Independent assortment and crossing over both occur in meiosis and not mitosis right?
Also what stage do they occur
Is random segregation the same thing as independent assortment??
How would you draw a diagram to show DNA replication
For this question:
During protein synthesis the nucleic acids DNA and rna act in which of the following orders?
A messenger rna, transfer rna, dna
B DNA , transfer rna, messenger rna
C DNA, messenger RNA, transfer rna
D transfer rna, messenger rna, dna
Would the answer be c??
Thanks!
Also for this question I think the answer is b am I correct?
All of the following plant transport processes are directly driven by osmosis , except one .which one does not directly involve osmosis?
A guard cells losing turgor pressure
B oxygen diffusion into leaves
C transpiration
D translocation
Isn’t translocation the movement of sugars though not the movement of water?
Would the answer for this question be d??
Which of the following best describes a gene?
A a single DNA molecule wound around proteins
B one leg of a pair of blue denim pants
C an allele that exists in 2 or more forms
D. A sequence of DNA nucleotides that encode a protein
Thanks!
Sorry for all the questions...
How would you explain the relationship between the circulatory and respiratory systems?
They both work together to maintain homeostasis ..?
Hello for this multiple choice question is the answer c?
Some living cells were maintained in a culture medium under aerobic conditions. They were supplied with glucose labelled with radioactive carbon-14? Which of the following is likely to be true
A carbon14 atoms would be found in NADH
B carbon 14 atoms would be found in atp
C carbon 14 atoms would be found in carbon dioxide produced by the cells
D Carbon 14 atoms would be found in pyruvate
Thanks
Pls can someone help me with this question
Hello for this multiple choice question is the answer c?Yeah I'm pretty sure it's C. The question states "aerobic conditions" so that implies that aerobic cellular respiration was being observed. In cellular respiration, the reactants are glucose (which was supplied with radioactive carbon-14) and oxygen, whilst the products are carbon dioxide and water. The logical aim of this experiment would be to trace the movement of the glucose molecules and the logical conclusion would be that the carbon-14 isotope ends up in the carbon dioxide product. Therefore, the answer should be C.
Some living cells were maintained in a culture medium under aerobic conditions. They were supplied with glucose labelled with radioactive carbon-14? Which of the following is likely to be true
A carbon14 atoms would be found in NADH
B carbon 14 atoms would be found in atp
C carbon 14 atoms would be found in carbon dioxide produced by the cells
D Carbon 14 atoms would be found in pyruvate
Thanks
Ok thanks!Yes. The liver breaks down excess amino acids (which make up protein) to make ammonia, then converts this into urea.
Also for this question
From which of the following is the waste product urea formed
A sugars
B fats
C protein
D Glycerol
Is the answer c??
For this question:Yes, the answer is a.
Atp synthase produces atp.....
A during the electron transport chain in the krebs cycle of cellular respiration
B only during glycolysis in cellular respiration
C in cellular respiration and the light dependent reactions of photosynthesis
D directly from the photolysis of water
Would it be a??
Thank you for your help!
Two birds with the same ancestor have evolved different beak shapes suited to eating different types of food eg insects and fruit.
Would this be an example of divergent evolution?
Humoral immunity or humoural immunity?
Which is the correct
Humoral immunity or humoural immunity?Humoral immunity.
Which is the correct
For this question:Yeah, ATP. ATP is what provides energy for muscles to contract. It's the best way of providing energy to cellular processes, by breaking the bond to a phosphate and releasing energy contained in the bond.
Two proteins actin and myosin are responsible for the contraction of muscles. Cellular extracts of these proteins will contract in a Petri dish in the presence of certain mineral ions. However this only occurs if a certain molecule is also present. This is
A adp 'unloaded' energy molecule, the bond to the 3rd phosphate has been broken and released energy already.
B Glucose The glucose needs to undergo cellular respiration in order for the energy to be converted to a form thats useful to the cell (ATP)
C nad An 'unloaded' carrier of H ions and electrons, not useful to help cell move
D atp
Would it be atp?
Can someone explain
Hi,
I got this question on edzion
Question 3. [6 marks]
Evaluate whether sexual or asexual reproduction is more favorable for the continuation of a species.
Anyone got any idea how to do it?
Yeah, ATP. ATP is what provides energy for muscles to contract. It's the best way of providing energy to cellular processes, by breaking the bond to a phosphate and releasing energy contained in the bond.
Some ideas for you to think about
Which method of reproduction produces more variation?
Why is increased variation in a population beneficial?some hints-sexual reproduction -> mutation, independent assortment, crossing over, fertilisation create variation
-asexual reproduction -> mutation only source of variation
-variation is important for natural selection to occur
-in event of environmental change, it's more likely that in a population with more variation there will be one or some individuals with beneficial traits that allow it to survive --> overtime the population can adapt as a whole through natural selection
-organisms that produce asexually will be more similar and therefore may be wiped out because none can deal with a sudden environmental change
Can someone please explain to me how polypeptide synthesis and DNA replication are related to each other?
Also if anyone has any assignments that they've completed on polypeptide synthesis, I would definitely appreciate it if you could upload it or send it to my email.
Thanks! :)
What is PCR in simple terms and is it used in both DNA profiling and sequencing.
Hey! :D
Polymerase Chain Reaction (PCR)'s aim is to rapidly create many copies (can be thousands) of a DNA unit (kind of like a printer, but for DNA). From this amplification, the DNA can be used by scientists as it is easier to study, test and observe. It is advantageous as it is cheap yet effective.
PCR is used in DNA Profiling to increase the amount of DNA present to study in the next stage of Profiling, Gel Electrophoresis (comparing bands).
PCR is used in DNA Sequencing also.
I hope this helps!
Coolmate 8)
How would you go about tackling this question?
Evaluate the use of whole organism cloning in agriculture. Include considerations of the social, ethical and environmental implications of its use.
How many homeostatic processes do we need to know? The syllabus says glucose and temperature which I have already done, however my school is doing homeostasis for water balance where we go in depth into kidney function along with a kidney dissection. Is this really needed for HSC and am I better of not bothering about this as I have already done temperature and glucose in my own time?
Hi, I'm having difficulty solving this question. Could you help?