VCE Biology Question Thread

[RazzMeTazz]

So, if cytotoxic T cells bind to MHC class 1 markers and then are stimulated to divide (as a result of interleukins produced by effector T helper cells) into effector cytotoxic T cells and memory cytotoxic T cells, do these effector cytotoxic T cells have to once again bind to a complementary MHC class 1 marker on an infected cell in order to release perforin? Or not? Since its parent cytotoxic T cell became activated as a result of binding to a MHC class 1 marker?

[vox nihili]

So, if cytotoxic T cells bind to MHC class 1 markers and then are stimulated to divide (as a result of interleukins produced by effector T helper cells) into effector cytotoxic T cells and memory cytotoxic T cells, do these effector cytotoxic T cells have to once again bind to a complementary MHC class 1 marker on an infected cell in order to release perforin? Or not? Since its parent cytotoxic T cell became activated as a result of binding to a MHC class 1 marker?

They do indeed have to bind to the appropriate MHC class I marker. You're going way too far into it though...

[RazzMeTazz]

They do indeed have to bind to the appropriate MHC class I marker. You're going way too far into it though...

Haha okay thanks for the clarification though

[RazzMeTazz]

Does the myelin sheath surrounding the axon allow for the rapid transmission of the electrical impulse and prevent the loss of electrical impulse?

I read that it stops the message from 'leaking' but was unsure what this exactly referred to..

Also, are the different types of receptors (chemoreceptors, pain receptors, mechanoreceptors etc.) neurones themselves?

[vox nihili]

Does the myelin sheath surrounding the axon allow for the rapid transmission of the electrical impulse and prevent the loss of electrical impulse?

I read that it stops the message from 'leaking' but was unsure what this exactly referred to..

It makes it go faster, that's all you need to know.



The extra stuff: it stops sodium ions and potassium ions from leaking into the interstitial fluid. It also facilitates something called Saltatory conduction, which means that you can "skip" big sections of the axon when passing on the message, rather than opening up all of the sodium channels.

[shivaji]

When signalling molecules bind to receptors, (cytoplasmic or receptors on the cell membrane), is it necessary to say in a question they require a complementary shape as well as charge?

[shivaji]

Also, do we have to remember things such as what makes up a sucrose (glucose + fructose) etc?

[vox nihili]

When signalling molecules bind to receptors, (cytoplasmic or receptors on the cell membrane), is it necessary to say in a question they require a complementary shape as well as charge?

Complimentary structure (Y)

[AllG_]

1) Do we need to know the differences of transcription and translation in eukaroytes and prokaryotes?
2) What are transcription factors? Do we need to know their function?
3) Do we need to know gene conservation? I've noticed its no longer on the study design anymore
4) To create transgenic organisms, does the inserted DNA have to come from a different species? Or can it just be any foreign DNA
5) Does the genome include ALL genetic material including RNA?

Thanks!

[vox nihili]

1) Do we need to know the differences of transcription and translation in eukaroytes and prokaryotes?
2) What are transcription factors? Do we need to know their function?
3) Do we need to know gene conservation? I've noticed its no longer on the study design anymore
4) To create transgenic organisms, does the inserted DNA have to come from a different species? Or can it just be any foreign DNA
5) Does the genome include ALL genetic material including RNA?

Thanks!

Try to answer some yourself and then have people confirm whether you're right or not

[dankfrank420]

Just completing the LisaChem 2013 exam and it says..

"Different theories exist of the speed of evolution. Explain the differences between 'gradualism' and 'punctuated equilibrium" theories.

We never looked at this in class, can someone please explain them to me?

species change slowly and constantly vs. species change in short, rapid bursts with little change in between these periods

[sandrag]

Are the models of evolution (i.e. gradual vs punctuated equilibrium) on the study design?

[vox nihili]

Are the models of evolution (i.e. gradual vs punctuated equilibrium) on the study design?

Nope

[sandrag]

I know that homologus structures provide evidence for divergent evolution, however, do analogus structures provide evidence for convergent evolution?

[sparkyblossom]

I know that homologus structures provide evidence for divergent evolution, however, do analogus structures provide evidence for convergent evolution?

Yep, they do