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AQA Biology B2 - Unofficial Mark Scheme

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Reply 40
Original post by Naco88
I got that the athlete ran for 1.5 minutes.


I got 2 whats the right answer
Reply 41
Original post by Blahblahblah7
The 5 marker for speciation was about the foxes I think? I didn't even read the information as invigilator said 5 mins left.

Yeah there was.
Reply 42
Original post by Blahblahblah7
The 5 marker for speciation was about the foxes I think? I didn't even read the information as invigilator said 5 mins left.


Yeah same and yeah it was. But there was a question after that apparently
Original post by Adamtoo
Yeah same and yeah it was. But there was a question after that apparently

It was only a one mark question, no need to worry
I said how much the plant grew omggggg also WTF IS PHENOTYPE AND GENOTYPE AHHHH
Original post by ozziess
For the quadrat question I got 20 flies, then 62.5metres in total, so I got 0.32metres per metres squared, leaving me with answer or 1,300


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
Reply 46
Original post by mellowjoker
What did everyone get for the genotype, phenotype and gametes question for the mother, father and then children? I couldn't remember what a phenotype was and so I'm pretty sure I completely messed up that page :frown:
I put as the phenotype Bb and Bb and then the Genotype I put heterozygous and gametes I put XY and XX - I'm certain I've got this entire page wrong as it was something I only briefly revised and now wish I had spent more time on!


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That's what I put I think and I revised it quite well


Phenotype is whet you see e.g. Brown hair
Genotype is what's there e.g. Bb
And for Dad I put XY and mum is XX
For the question on the milk I put the advantage was it was cheaper as less energy used to reach the same height and the disadvantage as does not kill all the bacteria.

Also for the one about read hair i put: fathers and mothers phenotype were brown hair, their genotypes were both Bb and their gametes were both B and b. Therefore there was a 75% chance of brown hair and 25% chance of ginger hair.

For the runner i put 3 minutes as the graph said it showed the change in heart rate or whatever while he was running.

For the one about the picto things whatever they were, i put 6.6, 13.2, 3.3 and the egg cell was 6.6.

For what was wrong with quadrat I said do more samples, use a smaller quadrat 1m^2 rather than 25x25 and dont place it in areas where only the plants were


Not too sure what about everyone else, anyone get the same?
Reply 48
Original post by danniconda
It was only a one mark question, no need to worry


Ah okay, that's fine.
Reply 49
Here is a 6 mark response to the question. Note that ANY other suitable values will award marks as well.

First, fill the beaker with 50ml of water and place the plant inside it. Next, lay the ruler down beside the beaker. Place the lamp 30cm away from the beaker, and turn it on. Count the amount of oxygen bubbles produced in 1 minute. Once the initial test is done, move the lamp 5cm closer to the beaker and repeat the process. To make the test fair, you must keep the amount of water at 50ml. You must also keep the power of light from the lamp the same. You must also use the same plant throughout. Furthermore, you should have many people counting the bubbles produced and average this, to minimise human error. Once the yet is done, repeat it 2 more times to get an average.
This was my answer that I wrote in the exam, I'm prerty sure that it got 6/6.
Hope this helps
Idiots, the length of the quadrat was 25 CM. So the area of the quadrat was 0.0625m*2
Reply 51
Original post by mrpaper
for the 6 marker I said to put soil in the beaker with a constant amount of water and then put the bulb a certain distance away from the plant then measure the plant and move the light back 5cm and measure again next week
control variables - amount of water and amount of soil
changing the light intensity
is this still right or?


I never mentioned soil as pondweed so I thought just need water?? But idk

Other than that I've done same thing
Reply 52
Original post by JAOASHAIL
Idiots, the length of the quadrat was 25 CM. So the area of the quadrat was 0.0625m*2


Yeah I got that as well so for the 10 quadrant it was 62.50??
1)Total number of plantains=202)Total area of 10 quadrats (in m^2)=6250
3)Mean number of plantains per m^2= 20/10=2
4)Total area of the field=5000
5)Estimated number of plantains in field=10,000
Original post by Blahblahblah7
The advantage of catalase was that it doesn't require fossil fuels to heat milk to 138



Disadvantage it said above question that H2O2 (hydrogen peroxide) doesn't kill all bacteria but heating will.




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.
Reply 55
Original post by spoony2799
1)Total number of plantains=202)Total area of 10 quadrats (in m^2)=6250
3)Mean number of plantains per m^2= 20/10=2
4)Total area of the field=5000
5)Estimated number of plantains in field=10,000


I'm not too sure as I'm crap at maths but I always thought that even though it added up to 20 you still had to do (3+4)/2
What was the mean per m^2?
Original post by JAOASHAIL
Idiots, the length of the quadrat was 25 CM. So the area of the quadrat was 0.0625m*2


didn't it ask for the area of all the quadrats (10)? so you'd do 25x25x10 then divide by 100 to get metres
Original post by RevisionGuide
For the 6 marker, didn't you only have to write about the use of the equipment given in the question, and not using any other equipment such as a stopwatch or test tubes like you mentioned


Yeah I know, I cocked up.
Original post by Blahblahblah7
The pictograms thing said that A is a cell then B is double its size then it spilits (C) so back to same size as A then that splits again

And D,E,F,G are sperm cells

So A = 6.6
B = 13.2
C = 6.6
And D onwards are 3.3 I think???




What was the organ where the meiosis took place? is it testes...

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