Edexcel A2 Biology Unit 5 (6BIO5) - 22/06/2011- OFFICIAL THREAD !

I really appreciate this thread guys! We just need to ace this one now, considering how **** most of us found Unit 4...seriously, what was up with it?
Anyhow, if any of you are willing to share Topic 8 notes, I'll be really grateful! Do you think they will make this exam easier than Unit 4, lower the boundaries maybe?

Hi there,

Any of you done the practice questions for Unit 5 Topic 7 in the Edexcel A2 biology purple revision guide (pp58) ?

I don't know if it is a mistake on the question or me being dumb - but on question 4, about the percentage difference of the H zone, I have no idea how they got the answer!


I've noticed a couple of mistakes in the guide, so hoping it is them and not me!

Any one help?
Thanks
Jen

Finished spec notes for topic 7, theyre here if anyone wants them

Has anyone seen the urgent clarification notice issued by Edexcel for the scientific Article.
Was terrified when my tutor emailed me saying there had been and error, until you read it: they just missed out the word 'baboons' from page three, paragraph six. lol

Do you have for Topic 8 as well?

Can someone help me out regarding the June 2010 paper please

Question 2d: I thought the resting potential was restored by the reversal of ions due to the Na/K pump, which uses ATP. And then an equilibrium is reached between K+ conc. gradient and the electrochemical gradient (as outside is more +ve than inside)

But the MS makes no reference to this pump

I think the mark scheme just focuses on the movement of potassium but the sodium/potassium pump is right too. Apparently, the mark scheme is only a guide and the examiners sometimes give you marks for stuff that's not exactly on there

I was also confused about 2b cause I thought the membrane is always permeable to potassium and just increases in permeability due to opening of voltage gated channels during repolarisation. However, the mark scheme says that at position A, it is only permeable to sodium?

It was a lot to take in the first time I read it, but give it a couple more goes over the next day or two and it will sink in

It did seem to get a bit complicated towards then end as it talks on about erg1a erg1b etc, but I think you just need to revise hard on topics that will likely be suggested from the material such as explaiing Gene therapy (Germ line/Somatic therapy and the different methods of application - using viral vectors/plasmids etc). I have a feeling they might also ask how transcription factors/gene expression works and the method of action of hormones/steroids etc. Maybe how genetic mutations occur too and how they can be inherited (punnet squares/monohybrid inheritance)?

Let's just hope that the paper isn't as much of a nightmare as Monday's Unit 4

i agree with top 2 posts... stupid edexcel... don't understand it.... the er even says that we did not credit mention of Sodium Potassium pump, whereas pretty much every other reference ive used has mentioned the Sodium Potassium pump in returning to resting membrane potential

omg unit 4 was terribllee!!!! i had to keep checking the front to make sure it wasnt unit 2 by accident!

could you explain to me how transcription factors work?