Biology B3 Mark Scheme 21/05/12

You had to say blood was squeezed at high pressure into the bowman capsule, all glucose was squeezed through. As the liquid flowed along the nephron the glucose was reabsorbed back by ACTIVE TRANSPORT this is because there is a low concentration inside the nephrons and high concentration of blood in the capilieries around the nephron.

I bet the mark scheme looks for
-glucose passes through filter
-reabsorbed by both active transport and diffusion
-useful substances

I put about it passing through the filter, the useful substances and diffusion but not the active transport part, how many marks do you think I'll get?

1 evidence that he ran 6 times?
6 peaks in the graph

2 how long did he rest after last sprint?
2.5 minutes

3 during exercise heart rate increases why?
more oxygen for aerobic respiration for energy for muscles also removes carbon dioxide and lactic acid

4 why are the jars filled with nitrogen and air tight?
the lid prevents micro-ogransisms contaminating the culture and the nitrogen ensures the conditions in each jar are the same

5 main gas in biogas appart from methane?
Carbon dioxide

6 percentage of methane for 2.5% fish fat?
0.62

7 conclusion?
adding fish fat increases the proportion of methane

8 why would the farmer not put fish fat in his biogas generator? (he lives 112 km away from sea)
he lives far away from the sea (fish)

9 what is fusarium doing?
aerobic respiration

10 why is important to keep mixture moving?
to mix Fusarium with the oxygen and prevent it from sedimenting

11 why not use paddles?
the branches of the fusarium would get damaged by the paddles

12 why chicken better for body builders?
chicken has more protein

13 why mycoprotein better for health?
less fat and less cholesterol

14 why not diffusion?
diffusion can't happen against a concentration gradient so the concentration inside the plant would be the same as outside

15 what was uaed instead?
active transport

16 how do lots of roots help absorb ions?
larger surface area

17 why lots of mitachondria?
to produce energy for active transport

18 why lots of starch?
starch is converted to glucose for energy

19 what is in healthy urine exept water?
Urea & (exess) mineral ions

20 what happens to glucose in kidney?
the glucose is filtered out of the blood then it is reabsorbed by active transport

21 why glucose in diabetic urine?
there is too much glucose to be reabsorbed (not enough energy avialable for the active tranpsort required)

22 conclusion?
with maltose increasing DAS concentration decreases the percentage sugar used by yeast. glucose and sucrose not affected

23 why maltose not absorbed by yeast?
maltose too big to be absorbed by yeast

24 why maltose absorbed when DAS not added?
the enzymes digests maltose into two molecules of glucose which can be absorbed and DAS stops production of this enzyme so maltose cannot be broken down

25 effect of DAS on alcahol production?
DAS reduces the percentage of alcohol produced

26 why beer company not use DAS?
DAS decreases the amount of alcahol produced & the toxins can make consumers ill

this is what i put i hate boilogy but it's so easy
i recon 35 = A* but there is no reason why it couldn't be 38/39 i don't trust boilogy people to be consistent with mark schemes or to say that there will be no questions on biogenesis lol

woah! this is creepy I put nearly all the same answers as you XD, and yeah I think it could be more like 38/39 for an A* this year because according to my Biology teacher at school the government have been saying that Biology GCSE is too easy (which it is really) so apparantly they have to make the grade boundaries higher so that fewer people get A*s

woah! this is creepy I put nearly all the same answers as you XD, and yeah I think it could be more like 38/39 for an A* this year because according to my Biology teacher at school the government have been saying that Biology GCSE is too easy (which it is really) so apparantly they have to make the grade boundaries higher so that fewer people get A*s

Why is there glucose in diabetic's urine:

I put because levels in the blood are so high that not all of it can be re-abosrbed via diffusion and active transport and so some is left in the filtrate to pass out of the body as urine.

What would i get do you think?

personally i would award 2 but you may get 3 if the marker is nice (if nice markers exist lol)

marks are most likley awared for:

not all reabsorbed (1)

because lots of energy needed to move the exess via active transport (2)

What do people think the grade boundaries will be for this paper? And is it true that they are making them higher this year, because thats what my biology teacher has told everybody in our set?

It was only two marks wasn't it?

yes i was i realise now lol

almost definatley 2

no marks for left in filtrate or pass out of body

but you may loose a mark for referance of diffusion (but i don't think they are that nasty hopefully)

Just wondering, did anybody do the B2 exam today too? I actually found that exam harder than the B3 one and its supposed to be the other way round XD, anybody else find this too?