VCE Biology Question Thread

[Erutepa]

do we need to know the immunoglobulins like IgG IgE IgD

I think you should know that each of them exists but specifics are probably not needed as it is not specified in the study design
However if you want to know their basic functions and toles, there a plenty of helpful tables you can search for which summerise the function nicely.

[benmcleod]

do we need to know the immunoglobulins like IgG IgE IgD

It's worth knowing that lgE is the antibody involved in mast cell allergic reactions. Apart from that, no.

[benmcleod]

The 2012 exam 1 report (SB-8c) says that more CO₂ is used in photo synthesis than is released in cellular respiration. But i was under the impression that 6CO₂ is used/produced in each? Can anyone clarify what they mean here?

[Sine]

The 2012 exam 1 report (SB-8c) says that more CO₂ is used in photo synthesis than is released in cellular respiration. But i was under the impression that 6CO₂ is used/produced in each? Can anyone clarify what they mean here?

Yes it is correct that photosynthesis uses 6CO2 and aerobic cellular respiration produces 6CO2.
However, the rates of each of theses reactions  aren't always the same. So rate of use of CO2 for photosynthesis is more than the rate of production via cellular respiration.

do we need to know the immunoglobulins like IgG IgE IgD

Not really might be good to now IgG is maternal antibody that can transfer via the placenta to give protection to the fetus.
IgE - allergic reactions
IgD - definitely don't need to know since the function is really obscure.

[benmcleod]

Yes it is correct that photosynthesis uses 6CO2 and aerobic cellular respiration produces 6CO2.
However, the rates of each of theses reactions  aren't always the same. So rate of use of CO2 for photosynthesis is more than the rate of production via cellular respiration.

Ahh okay, I sorta assumed that all the glucose produce would eventually be used up, but I guess if the rate of ps outweighs the cells energy demand over time there will be more CO2 used. Thanks for your help!

[011116]

I ask to many questions  one more; subunit and toxoid vaccines do we need to know it, as the study design suggests on herd immunity
ps. thank you for the respones

[Erutepa]

I ask to many questions  one more; subunit and toxoid vaccines do we need to know it, as the study design suggests on herd immunity
ps. thank you for the respones

Don't need to know these.
just know how a vaccine generally works:
a substance containing the antigen of a specific pathogen which is capable of stimulating a humoral immune response producing memory B and T lymphocytes.
Yes, also know about herd immunity

Also, there is no such thing as too many questions (in fact I sustain my self solely off answering questions and you wouldn't want me to starve, would you?

[Azim.m]

Is transcription a reaction? Is translation a series of reactions?

[Erutepa]

Is transcription a reaction? Is translation a series of reactions?

Transcription is a process.
Important in Transcription is the condensation polymerization reaction that creates a peptide bond between amino acids.
so I suppose it would be a 'series of reactions' but I don't think I would call it than in a response. I would just go with a chemical process.
I also wouldn't call transcription a single reaction either, I would again call It a process.

[Sine]

Is transcription a reaction? Is translation a series of reactions?

yes transcription involves chemical reaction since there is an addition of nucleotide onto a growing chain however in terms of VCAA the important aspect is the whole process.
Also Translation it's important to understand the whole process which involves reaction but you don't need to know any of the reactions.

[starby]

just need clarification,
Does the APC present to a Th cell or the naive B cell because i have read both in different sets of notes

[Sine]

just need clarification,
Does the APC present to a Th cell or the naive B cell because i have read both in different sets of notes

Present to a Th cell which uses it's T cell receptor.
The APC is usually a dendritic cell

[joanna120728]

1) How do cytotoxic T cells destroy cells? Can i say they release cytokines that bind to receptors on the infected cells which induces apoptosis in those cells?

2) Is the helper T cell that binds to the APC specific or not? As in is there only one helper T cell that can bind to the APC?

3) Is speciation a process/mechanism or result? Same for genetic drift. I'm guessing speciation is a result, and genetic drift is a mechanism. Not sure if this is relevant

4) If I were to write the products for anaerobic respiration (for animals), do i have to include NADH (and 2 ATP and lactic acid).

5) 2018 NHT quetion 10e. Why would herd immunity not be achieved at all if relenza is used?

Thanks in advance!

[darkz]

1) How do cytotoxic T cells destroy cells? Can i say they release cytokines that bind to receptors on the infected cells which induces apoptosis in those cells?

2) Is the helper T cell that binds to the APC specific or not? As in is there only one helper T cell that can bind to the APC?

3) Is speciation a process/mechanism or result? Same for genetic drift. I'm guessing speciation is a result, and genetic drift is a mechanism. Not sure if this is relevant

4) If I were to write the products for anaerobic respiration (for animals), do i have to include NADH (and 2 ATP and lactic acid).

5) 2018 NHT quetion 10e. Why would herd immunity not be achieved at all if relenza is used?

Thanks in advance!

1. They can either bind to/release cytokines to induce apoptosis or secrete perforin to lyse the cell
2. Yes, there is only one T helper cell for every antigen, therefore the antigen on the APC would be specific to a single T helper cell
4. Yes, the products are lactic acid, 2 ATP and NADH for anaerobic respiration, so I would write them
5. Relenza is an antiviral, it does not provide long term immunity to individuals, therefore herd immunity, which is the process where the majority of a population is immune to a disease to prevent the changes of people encountering it does not exist

[AISHAB]

Hi,

Could someone please explain the difference between gene flow and genetic drift? I get the gene flow is the flow of alleles between populations (migration) but what is genetic drift?

Thanks