VCE Biology Question Thread

[chekside]

For gene regulation, I think we just need to know the 2 different types of regulator genes and how they function to "regulate" the genes haha.

Could you please explain what you mean by the 2 different types as I haven't come across anything about that before.

[Coralista]

Could you please explain what you mean by the 2 different types as I haven't come across anything about that before.

I didn't really explain that clearly, what I meant is that regulator genes act in one of two different ways.
1. DNA-binding proteins bind to regions of nuclear DNA near genes and directly switch these genes on or off
2. Signalling proteins bind to receptors on the membrane of cells in their target tissue and trigger a series of intercellular reactions (signal transduction) that switch genes on or off

[Reus]

Do Ca2+ ions diffuse through the dendrites and are involved in the neurotransmitter release into a synapse right?

[doomdestroyer]

How would you explain the steps of an allergic response?

 * Allergen enters the body.
 * B cells produce antibodies specific to these allergens
 * These antibodies bind to mast cells
 * When the allergen enters the body again, they attach to the antibodies on the mast cells
 * This activates the mast cells to produce and release histamine
 * The histamine produces an allergic response

[vcestudent123]

* Allergen enters the body.
 * B cells produce antibodies specific to these allergens
 * These antibodies bind to mast cells
 * When the allergen enters the body again, they attach to the antibodies on the mast cells
 * This activates the mast cells to produce and release histamine
 * The histamine produces an allergic response

Thanks

[Reus]

* Allergen enters the body.
 * B cells produce antibodies specific to these allergens
 * These antibodies bind to mast cells
 * When the allergen enters the body again, they attach to the antibodies on the mast cells
 * This activates the mast cells to produce and release histamine
 * The histamine produces an allergic response

Would you also make mention of
 *APC's present the allergen to T-helper cells
 *T-helper cells release cytokine which stimulates the proliferation and clonal expansion of B cells
 *B plasma and B memory cells are produced.
 *B plasma antibodies attach to mast cells....

Or is this too excessive?

[millie96]

Can someone explain the difference between MHC1 and MHC2 markers?

and the process to which they're presented?

[Reus]

Can someone explain the difference between MHC1 and MHC2 markers?

and the process to which they're presented?

MHC1 are found on all nucleated cells in order for the body to recognise that they are self cells. Additionally MHC2 markers are found on macrophages and dendritic cells in which they present antigens to T Helper cells (CD4+) to initiate an immune response.

[vcestudent123]

Would you also make mention of
 *APC's present the allergen to T-helper cells
 *T-helper cells release cytokine which stimulates the proliferation and clonal expansion of B cells
 *B plasma and B memory cells are produced.
 *B plasma antibodies attach to mast cells....

Or is this too excessive?

Check out the answer for the 2012 Exam 1, Question 2 S.A

[Rachelle]

Are we allowed to mark our answers in MC in the question booklet, then circle them on the answer sheet?
What do you guys do?
Thanks.

[Reus]

Are we allowed to mark our answers in MC in the question booklet, then circle them on the answer sheet?
What do you guys do?
Thanks.

Apparently no. You can be reported for cheating, since the marking may have been induced during reading time? As they don't know.

[katiesaliba]

Would you also make mention of
 *APC's present the allergen to T-helper cells
 *T-helper cells release cytokine which stimulates the proliferation and clonal expansion of B cells
 *B plasma and B memory cells are produced.
 *B plasma antibodies attach to mast cells....

Or is this too excessive?

Personally I would (I'm too verbose ahaha), but VCAA reports only ever mention IgE immunoglobulins getting produced and secreted by B plasma cells which bind to mast cell etc etc.

Can someone explain the difference between MHC1 and MHC2 markers?

and the process to which they're presented?

The process is as follows:
-antigen is engulfed via phagocytosis, forming an intracellular vesicle (or phagosome).
-this phagosome combines with a lysosome, breaking down the antigenic fragments.
-peptide fragments from the antigen are complexed with MHC markers and then displayed on the plasma membrane



-

[theBRENDAN97]

Do we need to know about Barr bodies?

[Rachelle]

Apparently no. You can be reported for cheating, since the marking may have been induced during reading time? As they don't know.

No, as in during writing time, can we circle answers on question booklet?

[Coralista]

Do we need to know about Barr bodies?

Not as far as I know, I don't think thats in the study design.