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AQA Biology B2 - Unofficial Mark Scheme

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No the number of plantain's in that area was 160,000
Reply 61
Original post by bamzy123
for this question can you say the advantage is that it killed the type of bacteria that was mentioned in the question and for a disdvantage it doesnt kill all bacteria.


I'm not too sure but I don't see why not. After all it doesn't say that you can't say that.
Original post by Redcoats
What was the mean per m^2?


o.625/20=0.03125
Original post by JAOASHAIL
No the number of plantain's in that area was 160,000



I got 160 not 160,000
Reply 64
Yeah I got 1600, remembered it wrong :tongue:. 20 was the total flies and 62.5 was the total area, so to get the flies per metre you had to divide it by 62.5. I'm 100% sure the unofficial mark scheme is wrong.
Original post by babymarima
I got the same but the end amount i got was 1600, cos I multiplied 5000 by 0.32?

but the unofficial mark scheme is saying that you were supposed to divide 62.5 by 20 to get 3.125, but i dunno if that's right
Original post by bamzy123
I got 160 not 160,000

How?
For advantages and disadvantages of the hydrogen peroxide method, I put it would cause less environmental damage (as the other method worked at 138 degrees) and the disadvantage was that hydrogen peroxide can not kill disease causing bacteria so may not be able to kill some bacteria present in the milk (which are threatening to humans). Is this correct?
Original post by JAOASHAIL
o.625/20=0.03125


i got that too!! and i got 156 overall idk if anyone else has that
Original post by ozziess
Yeah I got 1600, remembered it wrong :tongue:. 20 was the total flies and 62.5 was the total area, so to get the flies per metre you had to divide it by 62.5. I'm 100% sure the unofficial mark scheme is wrong.


sickk thx
Original post by ranchers
i got that too!! and i got 156 overall idk if anyone else has that


You're getting A, not A*. The no. of plantains was 160000
heyy! guys any ideas for grade boundaries? easier or harder than last year????
Reply 71
Original post by bamzy123
What was the organ where the meiosis took place? is it testes...



Yep as sperm
Original post by JAOASHAIL
You're getting A, not A*. The no. of plantains was 160000

It was literally a 3 mark question, that isn't gonna be a major problem if you get the rest of the paper
Did no one write that the athlete ran for 1 minute because wouldn't the blood rate remain high while he pays off oxygen debt?
Original post by JAOASHAIL
You're getting A, not A*. The no. of plantains was 160000
its only one mark and I can still get A*
Reply 75
Original post by mariale99
heyy! guys any ideas for grade boundaries? easier or harder than last year????


This year is easier. I sat last years exam but due to entrusting circumstances I got 3 Cs for science when I was predicted an A so i decided to redo this year at college.

I think exam was harder last year but that may be because I had about 17 exams (12 GCSEs) and that put me under more pressure and now I'm only doing B2,C2 and P2
Reply 76
I got 160,000.

The dimensions of the quadrats were given in cm, not m. So it was 0.25mx0.25m, not 25x25.
How many marks was the plantain calculation question altogether? Wasn't it 4 marks?
Original post by Blahblahblah7
Yep as sperm


I put anus. Is it right?
Reply 79
0.25m^2 = 0.0625
0.0625 * 10 = 0.625
20/0.625 = 32

There are 32 plantains in 10m^2, NOT 1 m^2

5000/10=500
500 * 32 = 16000

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