Edexcel Biology (Unofficial) B2 Mark Scheme.

Original post by zoeolo

What do you think you'll need for an A*? I think I lost like 10 marks - though I'm not sure (the six marker on the heart threw me a little!

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Last year it was around the 54 mark? Although that might have been for Chemistry??

Reply 43

Original post by htkta

Yeah.. Mixed feelings I guess. The whole DNA extraction section I didn't like either, just because there's barely anything on it in the science textbooks :s-smilie:

For the dna 3 mark which said why do you use detergent solution and use crushed up peas I said u use a solution of detergent and salt to break down cell membranes and release dna and for the crushed part i just made up stuff using chemistry saying crushed up means larger surface area

Reply 44

ARK_REVISES

12

Original post by Asfand786

I put down 17, but idk if its right, some people put 18 and some put 15 but it was about an estimate so idk

I also wrote 17

Reply 45

Original post by ARK_REVISES

I also wrote 17

i put 19 it said estimate anyway

Reply 46

glowanti

14

Original post by keepyourapology

Could you also say that the mammals between the groups might mate and not have the same characteristics as their predecessors in group A?

Maybe but noooo idea I'm not a walking mark scheme :wink:

Original post by bue34 c

For the dna 3 mark which said why do you use detergent solution and use crushed up peas I said u use a solution of detergent and salt to break down cell membranes and release dna and for the crushed part i just made up stuff using chemistry saying crushed up means larger surface area

oh damnnnnn I didn't think of surface area! I just said it exposes the nucleus better so the detergent is more effective

Reply 47

Original post by bue34 c

For the dna 3 mark which said why do you use detergent solution and use crushed up peas I said u use a solution of detergent and salt to break down cell membranes and release dna and for the crushed part i just made up stuff using chemistry saying crushed up means larger surface area

For the detergent I said that the detergent breaks the cell and nuclei open so that it can release DNA, and for the crushed part I just said it being crushed means that the detergent will absorb easier but that's a load of waffle on my behalf..

Reply 48

i was originally aiming for an a* in biology I need it for a level, now i think a if I'm lucky, damn u edexcel!!!!!!

Reply 49

NextGenRemix

7

What was the question that had an answer of 42 about?

Reply 50

There was a graph showing the effects of light intensity on photosynthesis towards the end? For that I just said other limiting factors such as carbon dioxide might have affected the rate of photosynthesis? What did everyone else put?

Reply 51

username2174765

10

how much was the watson and crick question out of? i got the people mixed up :frown:

Reply 52

username2174765

10

Original post by htkta

There was a graph showing the effects of light intensity on photosynthesis towards the end? For that I just said other limiting factors such as carbon dioxide might have affected the rate of photosynthesis? What did everyone else put?

i said that and substrate and active sites being full

Reply 53

Original post by NextGenRemix

What was the question that had an answer of 42 about?

It asked you to estimate the next result and basically the numbers in the second half all went up by 7 so you had to add 7 to 35

Reply 54

after the anaerobic for yeast question i think the question about yeast with sugar was next which asked you to say an estimate for the volume of carbon dioxide for tube ...(can't remember name of tube sorry) then it said describe the concentration of carbon dioxide in the time i think, then it was suggest reasons for differences

Reply 55

NextGenRemix

7

Original post by htkta

It asked you to estimate the next result and basically the numbers in the second half all went up by 7 so you had to add 7 to 35

I think i got 17 for that one? Did others get that too?

Reply 56

Original post by NextGenRemix

I think i got 17 for that one? Did others get that too?

I got 19, but adding 7 doesn't make sense with the question because for the sucrose one it was a pattern, likewise i assumed the lactose one would also be a pattern

Reply 57

Izzzyxo

Did anyone answer the 1st 6 mark question about the artery disease thing and how it affected the heart/body cells??
I flopped so bad 😑

Reply 58

Farnosh

1

For the fossil question, I wrote about how some mammals in group A became extinct, and some mammals didn't fossilise (soft body tissues, and decomposition) and that caused the population to go Down. However, looking at this thread is making me panic because I never wrote about natural selection :frown:

Reply 59

Regertemah