HSC Biology Question Thread

[Einstein_Reborn_97]

For this question:

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!

Yes, the answer is a.

[Annasimon]

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?

[Annasimon]

Humoral immunity or humoural immunity?

Which is the correct

[Coolmate]

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?

Yes, this is an example of divergent evolution.

Humoral immunity or humoural immunity?

Which is the correct

I'm not quite sure about the correct spelling for this word (maybe Humoral Immunity?)

Hope this helps!
Coolmate

[Einstein_Reborn_97]

Humoral immunity or humoural immunity?

Which is the correct

Humoral immunity.

[Chocolatepistachio]

For this question:
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
B Glucose
C nad
D  atp

Would it be atp?
Can someone explain

[JeffBecker]

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?

[Owlbird83]

For this question:
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

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.

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?

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

[Bri MT]

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

Adding to this to give a couple of advantages of asexual reproduction

Spoiler

much faster population growth (given each mother has same amount of daughter) & no need to find a partner before reproduction (which can take energy and resources, open self to predation risk, disease etc.).

As Owlbird has said, the huge advantage of sexual reproduction which sees it evolve again and again is increased diversity

I haven't looked into HSC assessment much but hopefully this information helps you form a syllabus-suitable response

[Coolmate]

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! 

Hey neha.singh4!

Polypeptide Synthesis and DNA Replication are related to each other. DNA Replication is the process of producing two identical DNA units from an original DNA unit, whereas Polypeptide Synthesis is the process of creating polypeptide chains, ultimately folding to form a functional protein. Firstly, DNA Replication must occur so there is a DNA unit available to be transcribed by mRNA and translated by tRNA (both processes in Polypeptide Synthesis).

Secondly, when a protein is required to be produced, the process of Polypeptide Synthesis is initiated where it uses a DNA molecule's template strand (From DNA Replication) to match opposing bases (EG. A - T or C - G), which after the processes of mRNA and tRNA, produces a protein. (Polypeptide Synthesis)

Hence, if DNA Replication did not occur, then Polypeptide Synthesis would not be able to occur as a result of no genetic material/ codons, meaning the mRNA cannot match complementary bases, leaving tRNA with nothing to translate. This means a protein cannot be produced, affecting the functions of certain parts of the body (EG. Hair Growth). But because (usually, unless a mutation is evident) DNA Replication occurs, this means so too can Polypeptide Synthesis, thus a relationship (one cannot occur without the other)

---> This image illustrates the process of DNA Replication

---> In this image you can see how Polypeptide Synthesis relies on the DNA unit to create functional proteins

About the assignment question, sorry I don't have one that I completed on Polypeptide Synthesis. Could you ask your teacher to see samples of assignments from last year?

I hope this helps!
Coolmate

[Maroon and Gold Never Fold]

Can anyone explain to me DNA profiling and sequencing in simple terms and describe their differences.

[Coolmate]

What is PCR in simple terms and is it used in both DNA profiling and sequencing.

Hey!

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

[Maroon and Gold Never Fold]

Hey!

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

helps a lot

[neha.singh4]

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.

[Coolmate]

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.

Hey neha.singh4!

This is a question that not only tests a wide range of content, but also connections between content in the syllabus. In addition, these questions are a great way to revise, as they teach you question structure, succintness and a wide variety of content.

If I were answering this question, I would go about it like this:
1. Split the question up into parts:
Evaluate (Make a judgement based on criteria: NESA Glossary of Key Terms) the use of whole organism cloning (This is the overarching main topic required to be discussed) in agriculture (Not medical or industrial but agricultural; This is asking about the effects on agriculture only). Include considerations of the social, ethical and environmental implications of its use (We must include these 3 vital considerations in the response).

2. See if you can use the question to your advantage:
This question specifies 3 vital implications we must talk about, so I would consider structuring your response like this:

Introduction
Firstly, make a stance/ opinion on the question in the first setence to demonstrate to the marker that you understood the question by providing a direct response. Next, define Biotechnology and slightly reveal what you will talk about in the following paragraphs.

1st Paragraph
Firstly, define what "Social" means, then get into the social implications of using Whole Organism Cloning and provide at least 2 examples to illustrate an understanding. Some social implications include, we are currently facing a major global issue of "Overpopulation" and cloning will only exacerbate this issue, another one is what about the telomeres (caps on chromosomes) of the cloned organism? Will they be shorter, indicating a higher death rate among cloned organisms?

2nd Paragraph
Firstly, define what "Ethics" are, then get into the ethical implications of using Whole Organism Cloning and like the first paragraph, provide at least 2 examples to showcase a broad length and depth of knowledge. Some ethical implications include, is it ethically viable to clone an organism? Does this contradict Bioethical considerations?

3rd Paragraph
Firstly, define what "Environment" means in this scenario, then get into the ethical implications of using Whole Organism Cloning. Then, using at least 2 examples, link your ideas. Some environmental implications include, taking in consideration our Biosphere, will the cloning of organisms 'upset' the Biosphere on Earth (EG. some populations may become extinct due to a higher amount of a predative species, interfering with the food chain)

❗REMEMBER - Continually evaluate within your paragraphs so you don't "waffle on" and indicate to your marker that you are answering the given question.

A classic example is Dolly the Sheep, who was cloned in 1996 and was only successfully cloned after 277 attempts (very expensive!)

I hope this helps and if you have any questions, please ask!
Coolmate