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# AQA BIOL2 ~ 21 May 2012 ~ AS Biology Tweet

Biology exam discussion - share revision tips in preparation for GCSE, A Level and other biology exams and discuss how they went afterwards.

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1. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
What did everyone get for the mitosis calculation question about working out the time taken for the entire cycle to to take place..it really confused me. And how did you get your answer?
2. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by Vinbitz)
What did everyone get for the mitosis calculation question about working out the time taken for the entire cycle to to take place..it really confused me. And how did you get your answer?
It's 2 hours.

90% in interphase
10% in mitosis

200 cells in total
20 hours cell cycle

Therefore you want 10% of 20

20*0.1= 2 hours
Last edited by F.U.N; 22-05-2012 at 12:06.
3. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
Thankyou F.U.N
4. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by Waki)
Is there a mark scheme anywhere for this exam?
There's an unofficial MS here: http://www.thestudentroom.co.uk/show....php?t=2007941
5. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by mzayn)
Anyone used the King Phillip Comes Out For Good Sex mnemonic?
keeping pants clean often favours good sex
6. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by emah123)
For the question with the graph that had rate of flow and pressure on it: for the first question which was describe the rate of flow I put water is lost through the leaf through transpiration. This lowers the water potential in the leaf. Water is drawn up the xylem. This lowers the water potential in the root and water moves in through the root via osmosis.hence increasing the rate of flow.

I realise now that I didn't actually use the graph and was wondering what I actually should've put. Can someone tell me the right answer? And how many marks might I get for my answer out of the 3 available??
Your answer still makes perfect sense; you included transpiration and the effects that will have on the rate of flow in the xylem which is what the question wanted. However, the key was that on the graph x axis was time of day. You needed to relate it to the factors affecting transpiration at the times of day. E.g. From midnight to 12pm there will be an increase in light intensity. This means more stomata will open, and so the evaporation of water from the plant's leaves will increase (transpiration) this will therefore cause more water to move into the leaves from the xylem and so the rate of flow in the xylem increases. Conversely from 12pm to midnight again.
You should most definitely get 2/3 marks though because you've included transpiration and water potential gradients.
Last edited by alexissocool; 22-05-2012 at 12:14.
7. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by alexissocool)
Your answer still makes perfect sense; you included transpiration and the effects that will have on the rate of flow in the xylem which is what the question wanted. However, the key was that on the graph x axis was time of day. You needed to relate it to the factors affecting transpiration at the times of day. E.g. From midnight to 12pm there will be an increase in light intensity. This means more stomata will open, and so the evaporation of water from the plant's leaves will increase (transpiration) this will therefore cause more water to move into the leaves from the xylem and so the rate of flow in the xylem increases. Conversely from 12pm to midnight again.
You should most definitely get 2/3 marks though because you've included transpiration and water potential gradients.
thank you!, I hope so but I'm worried i'll lose the marks because I didn't put anything to do with the time of day, therefore didn't relate to the graph!
Last edited by emah123; 22-05-2012 at 12:29.
8. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by emah123)
thank you!, I hope so but I'm worried i'll lose the marks because I didn't put anything to do with the time of day, therefore didn't relate to the graph!
You wouldn't get the marks then.
9. (Original post by doctorzing)
ok don't know if this is a stupid question but for the very first answer I put :
osmosis not diffusion as the organism was living in water and the o2 could be obtained form the H20. Thoughts?
Osmosis is the movement of water only, so you won't get the mark. :/

This was posted from The Student Room's iPhone/iPad App
10. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
when it asked for the missing group on the cellulose molecule i wrote

hydroxide/OH would i lose a mark
11. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by Whatever9999)
when it asked for the missing group on the cellulose molecule i wrote

hydroxide/OH would i lose a mark
no
12. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by sconter)
no
Thanks
13. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by Whatever9999)
when it asked for the missing group on the cellulose molecule i wrote

hydroxide/OH would i lose a mark
no
14. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by lulu61)
keeping pants clean often favours good sex
Mines: King Phillip Calls Order For Gay Sex

15. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by kiran18)
Mines: King Phillip Calls Order For Gay Sex

Ahahaha! Fairrr enough
16. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
17. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
GET OVER IT!!! ARGHHH!

sorry... slightly mad when more exams are looming...
18. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
Is anyone able to get hold of the official mark scheme and/or paper? x
19. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
How did everyone do?
20. Re: AQA BIOL2 ~ 21 May 2012 ~ AS Biology
(Original post by Sorro10)
How did everyone do?
284/300 overall - ecstatic