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aqa Biology Unit 2 AS level (BIOL2) ON 21st May 2012-possible questions

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Original post by calender1994

because a levels are getting harder and ive done all the papers from 2001 to 2012 and and am just trying to get more practice YOU DICK!!!

no need for that language

Reply 21

dekg140

I think the marks would be awarded for something like

-Hydrostatic pressure
-Caused by ventricles contracting
-pushes out small molecules through capillary walls
-Because capillary walls permeable/have holes
-As more tissue fluid formed, hydrostatic pressure reduced
-Proteins too large to go through capillary wall
-Lower water potential
-Tissue fluid moves back in by osmosis
-Down water potential gradient
-Rest of tissue fluid drained via lymph vessels

Just a rough guesstimate :smile:

Reply 22

Udderss

Original post by TheFootyKing19

Loved the 6 marker! Heaven :biggrin:

I didn't understand that question! :frown:

Reply 23

JDO9700

Any1 got unofficial markscheme for as level bio unit 2 ?

Reply 24

meinerawre

Original post by dekg140

But I thought the question was asking about its formation and return? ><

Reply 25

calender1994

Original post by Legha

no need for that language

haha its cuz im cool :cool:

haha ojoj

Reply 26

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?

Reply 27

calender1994

Original post by p_nolan212

Doing papers that aren't related to the current specification won't help, might want to try and sort your grammar out though for a few extra marks

Reply 28

Bello08

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?

No, oxygen required for respiration must be molecular oxygen (O2), that is dissolved in the water. Organisms living in water do not get oxygen for respiration from H2O. So it is diffusion, not osmosis, since osmosis is strictly the diffusion of water molecules.

Reply 29

dekg140

Original post by meinerawre

But I thought the question was asking about its formation and return? ><

Yeah, formation (how it leaves the capillary) and it's return (how it re-enters the capillary)

Reply 30

seanninetytwo

Original post by dekg140

Yeah, formation (how it leaves the capillary) and it's return (how it re-enters the capillary)

I thought that. So I summed up how it exits the capillary and how it is drained away and re-enters at the other way, cramming in every technical word. I forgot the name of the actual draining system so just guessed lymphatic (too scared to check if that's wrong, it probably was but don't tell me!). Also added what sort of substances can pass through and can be left. Then I had 10 minutes left at the end so filled the page with all my other knowledge on the tissue fluid and it's purpose to be safe.

Reply 31

Dansnail

Was I seeing things or was there a question on altitude? with the oxygen dissociation curve?

Reply 32

seanninetytwo

Original post by Dansnail

Was I seeing things or was there a question on altitude? with the oxygen dissociation curve?

Can't remember any questions on oxygen dissociation, but I forgot a lot of the test to be honest. What other things were there about oxygen dissociation/haemoglobin? Might jog my memory.