Year 12s: what will be the first way you research your future options? >>

AQA BIOL2 Biology Unit 2 Exam - 26th May 2011

Scroll to see replies

Reply 1720

EffKayy

Original post by swiftylol

What did you put for the question asking to explain the graph, difference between line A and line B?

I dunno
I can only remember talking about it prevents a water potential gradient from being established.. ?

Reply 1721

ReMos

I can only remember talking about it prevents a water potential gradient from being established.. ?
Positive Rating!

i was thinking about that, but i was more in the path of 'it just blocks everything' xD

Reply 1722

??????????????????

Original post by swiftylol

What did you put for the question asking to explain the graph, difference between line A and line B?

What question was this?

Reply 1723

swiftylol

Original post by ReMos

I put that that in B the grease covered the stomatal pores which did not allow water to leave through the stomata which prevented loss in eater which reduced loss in mass :s-smilie:

not sure if that is right tho :biggrin:

And the question before that, the one which asked to xplain the graph?

Reply 1724

EffKayy

Original post by ReMos

i was thinking about that, but i was more in the path of 'it just blocks everything' xD

LOL oh well.
aqa has ruined my life...
im just praying i've scraped an A.

Reply 1725

EffKayy

Original post by swiftylol

And the question before that, the one which asked to xplain the graph?

what did you put about b then?

Reply 1726

swiftylol

Original post by ??????????????????

What question was this?

Blah blah blah, some bish put grease on leaves, and put them on lines. A had no grease, B had grease.

Explain the shape of the graph that represents line A.

Reply 1727

??????????????????

Original post by swiftylol

Blah blah blah, some bish put grease on leaves, and put them on lines. A had no grease, B had grease.

Explain the shape of the graph that represents line A.

Oh I just said the grease was water proof.

Reply 1728

davis053

For the grease on plant B (or whatever) i said that the grease reduced light intensity to the plant which then meant the stomata did not open as gaseous exchange was not needed for photosynthesis.

Quite upset i didn't have to write Plasmodesmata in my paper :smile:

Reply 1729

ReMos

i think it was explain the graph for a for 3 mark? if it was then i put:
high rate of loss of mass because of higher rate of loss of water at beggining as water diffused out through stomatal pores(and transpiration or something)
(from 0-60)

from 60-onwards

water potential of cells is lower becaus there is less water (all was lost~) so less water evapourated to air spaces=less vapour diffuses out of stomata=less waterloss=less loss in mass
(lower rate)

Reply 1730

EffKayy

Original post by ??????????????????

Oh I just said the grease was water proof.

LOL @ how all of us have put different answers..
who knows what the right answer is...
LOL

Reply 1731

username607202

Original post by ??????????????????

Oh I just said the grease was water proof.

What about the stomata remaining closed in order to prevent movement of water by osmosis which would decrease its mass?

Reply 1732

Emily90

What are people thinking that the grade boundary is for a C?

Reply 1733

forsaker

It still loses mass because she only covered the upper surface with grease. She left the lower surface (which generally contains more of the stoma) uncovered and thus transpiration could still occur down there so it still lost mass, just not as much.

Reply 1734

CPN

How was it guys? Hard? Easy? Just wanted to know coz i have chemistry tomorrow!

Reply 1735

??????????????????

Original post by Wick3d

What about the stomata remaining closed in order to prevent movement of water by osmosis which would decrease its mass?

Could be anything. I just thought of it as an artificial waxy cuticle.

Reply 1736

username607202

Original post by ??????????????????

Could be anything. I just thought of it as an artificial waxy cuticle.

Don't worry it was only a few marks out of 85. :smile:

And who knows with AQA and their dodgy mark schemes.

Reply 1737

EffKayy

Original post by Wick3d

What about the stomata remaining closed in order to prevent movement of water by osmosis which would decrease its mass?

I think the main concept is about a preventation in a water potential gradient. The other user talked about waterproof = no water potential gradient. Stomata closed = no water potential gradient, therefore less loss.
I think i just mentioned w.p gradient reduced, so less loss of water :smile:

Reply 1738

Twigleheight

I came out feeling quite happy about it tbh, fingers crossed I did OK :smile:

I should really be revising chemistry now but wanted to have a quick look on here, it's turning into a 15 minute long look now xD
Hope you all found it OK :smile:

Reply 1739

username459260

will I get the mark for stating % difference as 52.2 because I used 9.2 NOT 9