VCE Biology Question Thread

[darkz]

1) Are cytotoxic T cells activated in a similar process to B cells (i.e by T helper cells' cytokines after both being exposed to the same antigen?)
2) Would the membrane structure be considered an argument supporting endosymbiotic theory? I always thought that it wasn't, due to bacteria not having double membranes.
3) Would it be ample to state that the steps of apoptosis are as follows:
 - Crucial proteins digested by caspases i.e cytoskeleton
 - Chromosomes condense, organelles digested
 - Cell shrinks
 - Cell blebs and breaks apart
 - Sends signals to macrophages to consume remains

1. Yes, they do work in the same fashion, however in the case of the cytotoxic t cells, they are first exposed to the antigen after binding with the antigen on an infected cell's MHC class I marker.
2. Yes, by having a double memebrane this does support the endosymbiotic theory, this is because when something is engulfed, e.g. by phagocytosis or endocytosis, it gets enclosed within a vesicle. Therefore, the hypothesis is that the outer membrane belongs to the original cell (the vesicle) and the inner membrane actually belongs to the bacteria etc.
3. Yeh looks good, although I would change the working to "cleave" proteins. And I don't believe that all organelles are actually broken down, as some are recycled

[jollyboat]

Hey, I was wondering what acronyms VCAA allows us to use on the year 12 exam?

I know that we can definitely use DNA, NADH, ATP etc. and that we definitely can't use ER, for endoplasmic reticulum. Specifically I was wondering about PCR, MHC, PAMP and PRR?

Thanks

[darkz]

Hey, I was wondering what acronyms VCAA allows us to use on the year 12 exam?

I know that we can definitely use DNA, NADH, ATP etc. and that we definitely can't use ER, for endoplasmic reticulum. Specifically I was wondering about PCR, MHC, PAMP and PRR?

Thanks

I would write out PCR, as for PAMP, PRR, MHC you can probably just use those abbreviations

[Bri MT]

Hey, I was wondering what acronyms VCAA allows us to use on the year 12 exam?

I know that we can definitely use DNA, NADH, ATP etc. and that we definitely can't use ER, for endoplasmic reticulum. Specifically I was wondering about PCR, MHC, PAMP and PRR?

Thanks

MHC would be fine. I feel like PCR *might* be okay but I'm not sure? I wouldn't risk it.

 If it isn't one you know you can use, just write out the term and put the acronym in brackets, and you can then use that acronym in that question afterwards.

eg. polymerase chain reaction (PCR) would allow identification of the suspect. This is because PCR ….

[hoddemi]

how exactly does adaptive radiation work? is it similiar speciation process to allopatric speciation except instead of a geographical barrier its availability of new niches in environment, which provide different selection pressures etc?

[napkin101]

Do we need to know the specific plant hormones? Thanks

[randy123]

Hey,

How do complement proteins work and which stage of the immune response are they.

thanks

[PhoenixxFire]

how exactly does adaptive radiation work? is it similiar speciation process to allopatric speciation except instead of a geographical barrier its availability of new niches in environment, which provide different selection pressures etc?

Yep. It’s not really that similar to allopatric speciation except needing variation and resulting in different species. The mechanism and time frame are completely different.

Do we need to know the specific plant hormones? Thanks

Definitely don’t need to know them

Hey,

How do complement proteins work and which stage of the immune response are they.

thanks

2nd line of defense (internal, innate)
(Copied from my notes)
Complement system: Group of more than 30 proteins, found in the blood that act together to produce 3 responses:
1. Opsonize pathogens: They stick on the surface of pathogens in the extracellular environment and make it easier for leukocytes to recognise them.
2. Attract phagocytes to the area: They are chemoattractants, phagocytes will be drawn to the source of complement proteins.
3. Create pores in bacterial membranes. Form a Membrane Attack Complex (MAC): They create a hole in the bacteria, causing fluid from the extracellular environment to rush in and rupture the bacteria.

[Erutepa]

Hey,

How do complement proteins work and which stage of the immune response are they.

thanks

Compliment proteins are part of the innate system.
They are a collection of proteins which circulate in the body and can be activated by the constant region of bound antibodies or by pathogens. Once activates a cascade of reactions occur activating many different compliment proteins which have different functions. Some proteins act as ospons, some act at chemo attractants and some form a membrane attack complex which can punch holes in bacterial membranes. I belive some may even induce degragranulation in mast cells (but not entirely sure)

[napkin101]

Definitely don’t need to know them

Thanks! Do you know to what depth we need to know plant hormones and specific information we need to know about them?

[PhoenixxFire]

Thanks! Do you know to what depth we need to know plant hormones and specific information we need to know about them?

Just need to know source and mode of transmission. Mode of transmission is endocrine, I’m not sure on source because I don’t know how specific they want your source to be.

[napkin101]

Thanks!

[EllingtonFeint]

How many ATP would you day are produced in each stage of cellular respiration??

Is this correct?
-Glycolysis: 2
-Krebs Cycle: 2
-ETC: ~34 (Not sure about this one...)

Anaerobic: 2 for either fermentation or anaerobic in animals (...?)

[Erutepa]

How many ATP would you day are produced in each stage of cellular respiration??

Is this correct?
-Glycolysis: 2
-Krebs Cycle: 2
-ETC: ~34 (Not sure about this one...)

Anaerobic: 2 for either fermentation or anaerobic in animals (...?)

This is correct.
The ETC actually produces 32-34 ATP, but it seems to be the consensus (from previous discussion) that you should stick with just one of the two for your answers.

[PhoenixxFire]

Anaerobic: 2 for either fermentation or anaerobic in animals (...?)

The only ATP is anaerobic respiration comes from glycolysis, so yes it’s two.