WJEC biology BY4 11/01/2013

Good luck with Cardiff!

Exeter AAB (already have the B, just resitting one paper in economics for an A, and biology for the other- although it's a first sitting)

I'm a third year

Thanks very much, good luck with exeter! sounds like you're close to getting in then! awh soo Am I lmao, I didn't sit the exams in the first year tho because I went to a new college and got depressed so came back to my old school

Is anyone retaking BY4? Ahhh bet im the only one

Meeee, I am!

Ahhh thank god haha! i'm so nervous... I only just started revising for it a few days ago only because I havent got anything to lose as I did get a B last time & retook by3 so hopefully that'll up my grade... anyway, wanna talk about BY4?

Same here hah!
Okay sure..What are you struggling on most?

Haha alright well that makes me feel slightly better then
Ahh where do I begin, well actually it's not too bad..
The kidney and nerve impulses all that action potential and resting potential stuffs just confuses me!

Yourself?

Ahh yes I don't like kidneys after ultrafiltration. Nervous system I'm ok with but need to revise the drugs bit. I hate photoperiodism tho!

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Ah cool, oh yeah! that drugs bit is annoying .. our teacher said we had to learn specific stuff about loads of drugs but in the WJEC book it just says we need to know about organophosphorus insecticides so my teacher is probably wrong! aha. I hate that too, as soon as I think I understand it I go to do a question on it and its like.... oh dammit

We ask some questions to test our knowledge?

Yeah don't think we need to do loads. Just how they behave e.g mimic neurotransmitter etc.
YES same! I can't do photoperiodism haha.

Indeed we can

Ah phew! Hopefully we'll learn... Eeek 6 days left though! Not going to think about that..

Sweet, well I will try to think of a question now then..

Describe ultrafiltration, and explain how the different layers of cells influence this process.

(I'm not the best at wording things but hope that's okay xD)

Arghhh!

It's okay, I'll bullet point the answer:
- Ultrafiltration takes place when the wider afferent arteriole brings the filtrate in to the glomerulus.
- As it passes through the glomerulus, it comes to the narrow efferent arteriole which creates a hydrostatic pressure.
- This pressure forces small soluble substances such as water and salts to leave the glomerulus and go in to the Bowman's capsule.
- The structure of the wall consists of the capillary wall which has small gaps, basement membrane which acts as a filter, epithelial cells called podocytes.

Sorry it's a bit rubbish haha!

Here's one for you (been used in a past paper)

Describe the formation of ATP in the electron transport chain.