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

looks like people are unsure about it. it was def better than unit 4 which was a mess, but do you reckon the boundaries will be higher than jan 11? in jan it was 64/90 for an A* in unit 5, was this harder or easier than that?

Just got this from my notes:

"Endocrine system in mammals – chemical hormones from endocrine glands carried in the blood plasma around the circulatory system. Slower acting. Can control long term responses such as growth and sexual development. Some are involved in homeostasis such as control of blood sugar. Some can be relatively fast e.g. effects of adrenaline in response to stress. Response may be widespread or restricted to specific target cells

Tropisms in plants – chemical growth substances e.g. auxins diffusing from cell to cell – some may go in the plant transport system (the phloem). Slower acting. Controls long-term growth responses e.g. cell elongation. Response may be widespread, but normally restricted to cells within a short distance of the growth substance being released."

got this from my slug notes too, I really mucked this Q up:

"With repeated stimulation, Ca2+ channels become less responsive so less ca2+ crosses the presynaptic membrane
Less neurotransmitter is released
There is less depolarisation of the postsynaptic membrane so no action potential is triggered in the motor neurone"

sameee, recon we'l get a mark for capillaries? maybe if we have a nice examiner

Just got this from my notes:

"Endocrine system in mammals – chemical hormones from endocrine glands carried in the blood plasma around the circulatory system. Slower acting. Can control long term responses such as growth and sexual development. Some are involved in homeostasis such as control of blood sugar. Some can be relatively fast e.g. effects of adrenaline in response to stress. Response may be widespread or restricted to specific target cells

Tropisms in plants – chemical growth substances e.g. auxins diffusing from cell to cell – some may go in the plant transport system (the phloem). Slower acting. Controls long-term growth responses e.g. cell elongation. Response may be widespread, but normally restricted to cells within a short distance of the growth substance being released."

got this from my slug notes too, I really mucked this Q up:

"With repeated stimulation, Ca2+ channels become less responsive so less ca2+ crosses the presynaptic membrane
Less neurotransmitter is released
There is less depolarisation of the postsynaptic membrane so no action potential is triggered in the motor neurone"

I put differential exon arrangement after introns are removed ARGHHHH. the word splicing slipped out of my F'n mind in that exam! do you reckon i'll still get that mark?

sameee, recon we'l get a mark for capillaries? maybe if we have a nice examiner

FML im gonna go sleep so i can revise for chemistry tomorrow

FML im gonna go sleep so i can revise for chemistry tomorrow

ah nice answer, yeah hopefully I got at least 1 or 2 for the hormones q, I was alright with the reason for why habituation happens, I learnt that quite well cus it wasn't in the past 2 papers for this unit so thought it was likely to come up, same with the spirometer practical, the other 2 core practicals have come up before so I figured it was spirometers turn!

OMG!!! i totally guessed that. i put less neurotransmitter is released as repetition of stimuli continues. Depolarisation of post knob gradually decreases, hence eventually below the threshold - not enough to induce an action potential hence gill does not get withdrawn.

goood! luck. I have that one too! 7th and last exam wohoo

im still learning most of unit 5 for the first time, caffeine pills on hand

how come...?

i would have thought that this one was easier than jan but more people 'waffled' in this one, the qs were harder except article qs and i made alot more silly mistakes in this one than i did in the mock (jan paper) i really hope grade boundaries are low :/

It was much better than unit 4. I think I got a U in unit 4, while I think I got the exact opposite of a U in this unit lol.