HSC Biology Question Thread

[Natasha.97]

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

[pikachu975]

most important (or most commonly asked) concepts to nail down in bio core? I have two days to prepare #ragrets

Hello!

I'd definitely recommend spending the 2 days memorising your notes only, forget about past papers you can do those for HSC.

I've got mine tomorrow so I'm memorising the entire course today but knowing the content is DEFINITELY more important than practising some questions, which you can't do anyway if you don't know the content!

Good luck, post here if you need any questions about the content answered.

[mjorfian]

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?

[pikachu975]

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?

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.

[Natasha.97]

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?

For me, doing past-papers (although open book) really helped in terms of pinning down the content (I learned more that way versus just reading notes) but everyone learns differently! I did trial past papers

[caitlinlddouglas]

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!

[Natasha.97]

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!

Hi!
Not 100% sure on this, but I think rods would be the type of photoreceptor stimulated. They are usually in charge of night vision, detection of movement, and light/shadow contrasts, forming a broad band around the edge of the retina. In terms of vision in bright light, the fovea is directed to whatever object is studied closely.
Hope this helps!

[idontlikeschool]

I know this isn't a question, but:

to all bio students sitting the cssa trial tomorrow, i just want to wish you all the best of luck. Don't be stressed.

[mjorfian]

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.

Decided on a happy medium and have been doing both together with the Edrolo videos - which basically cover dot points and ask you short answer/ multiple choice questions directed at the dot point right afterwards So far I've gotten through half of SFBH and communications. Ahhhh.

[sidzeman]

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

[pikachu975]

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

The terms are used together, so cells "differentiate then specialise into a ___ cell". They assist in maintenance of health because with mitosis the following occurs:

1) Gene responsible for mitosis is expressed/"switched on".
2) Mitosis occurs in cells.
3) The cells differentiate and specialise into skin/epidermal cells.

So this helps with growth and repair as cells can differentiate and specialise into required cells such as skin.

[Opengangs]

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

Hi, sidzeman!

Cell differentiation occurs during mitosis. When stem cells divide (undergo mitosis), they divide into specialised cells, as well as another stem cell. This process during mitosis is referred to as cell differentiation.
Cell specialisation can be seen as the result of cell differentiation. That is, they will have a specific function to perform within the body.

In terms of its assistance, cell differentiation allows an undifferentiated cell to become specialised. Because specialised cells do not perform mitosis and division itself, this is the role of cell differentiation; to undergo division, in order to become specialised.

On the other hand, specialised cells have a specific function to perform. Upon cell division, specialised cells will express the genes of a particular function (such as skin cells for repair), and thus, they have specific functions.

Hopefully, this has cleared things up! Differentiation and specialisation go hand in hand, because differentiation has a very minute part in cell division.

[sidzeman]

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

[Natasha.97]

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 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

[pikachu975]

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

Note that both of their works led to the "Chromosomal theory of inheritance" which means chromosomes carry genetic information (DNA) which is the means for inheritance