AQA BIOL5 ~ 17th June 2013 ~ A2 Biology

Hey, can someone please explain to me the difference between multipotent and pluripotent cells? Thanks

have you done some revision already or starting?

Just from generally reading it, prior to the question, it states that "The insertion of the DNA copy in one of the host cell’s genes may cause the cell to
make a non-functional protein."

I haven't checked the mark scheme but from what that suggests it must be a tumour suppressor gene. Oncogenes, undergo mutations as to produce a proto-oncogenes, which can function via two methods - producing excessive amounts of the growth factor (that would then bind with the receptors of the cells causing it to grow and divide), or permanently activating the receptors found upon the cell surface membrane (bringing about the same response). Because the question states a non-functional protein, it cant be the proto-oncogene, as that would result in the coding for a protein (that opposes what the question states). I don't ink I would have actually got that one in the exam :/

Yes I have started but it just too much to do in too little time. Need some kind of guidance on the best way to prepare especially the essay.

Anyone worried about not enough questions? (these were taken off exmpro)

Old Spec. relevant questions (NO MARK SCHEMES)
285 Unit 5 Questions, 40 Essay Questions:

http://www.newgrounds.com/dump/download/d1a020f94d5435660cead54555cae705

I love people like you! Always trying to help people. - Mark Schemes included on my skydrive if people go looking for them. =)
I would strongly advice people to use these, however, if you want them divided into sections, please check out my skydrive.

https://skydrive.live.com/?cid=AB9A51CE012167BC&id=AB9A51CE012167BC%21111

Divided into DNA, Neurons/Synapses, Negative Feedback and Homeostasis.
I have taken out the essays because the mark scheme is the same thing for hundreds of pages!

hey guys..
Initially i thought the more unsuitable an environment to more the species moves and changes directions it says in aqa book...

However doing an past question on kinses, its in your aqa text book . End of Chapter questions. Page 153. question 1. chaper9.. their is a question about a louse, and it says in a favorable environment the louse changes direction more frequently, so its likely to say in that condition..
so confused..!!

Does anyone know where I can get the nelson thornes answers to the examination questions for this unit.

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all on the first post on this thread

omg my school are doing the same thing it's so frustrating- I refused to do the mock today though (maybe that was bad of me) but I'm terrified at the lack of exam practice I'm gonna get as most my final revision is learning from past papers (

if you want some extra questions I have a .zip full of them cause I was worried about proper exam practice :P (most don't have the answers though)

There are a list of essay questions somewhere as well on an aqa document - I can't find it right now though

do u still hav the aqa document

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What is the refractory period, is it when the membrane is hyperpolarised or when the protein channels are resetting?

also I understand how this can make impulses discrete but how does this make them unidirectional?