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AQA Biology B2 - Unofficial Mark Scheme

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Reply 260
Original post by Azarhuntttt
For the 5 mark question in b2 for the genotype and stuff what did everyone put for each one. The questions were like

Parents genotype
Parents phenotype
Gametes

Offspring genotypes
Offspring phenotypes

Think I got it all wrong 😂


I honestly had no idea either. I just wrote B or b randomly...
Reply 261
Original post by Naco88
↑↑↑ In the poll above, an answer like '> 30%' would mean between '30%' and '40%' ↑↑↑


Remember a question? Post your answers below.
Follow me and I will try and post the answers for the Chemistry and Physics exams on Wednesday and Friday.
This mark scheme is not official and was made purely from what we saw in the exam.

AQA B2 Higher - Unofficial Mark Scheme (Updated Regularly) (Should have the last few questions of foundation)

1. Athlete Question
a)
i) Anaerobic means respiration without oxygen
ii) The athlete was running for 1.5 minutes.
b) How do you know it was anaerobic respiration?
The athlete produced lactic acid
2. Pond Weed Question

•

Put the pond weed in the beaker,

•

Fill the beaker with water.

•

Move the light close to the pond weed,

•

Count bubbles in one minute, / Measure oxygen produced

•

Note down your results,

•

Repeat experiment but move the light closer/further away from the pond weed each time.

•

To make it a fair test, use same amount of water, use same length/volume of pond weed, time it for the same length.

Question 2 notes: The answer could be any experiment to test how the amount of light intensity affects photosynthesis. The question stated that you did not have to write about the equipment pictured and it was just an example.
(6 marks)
3. Enzymes question
Circle Cytoplasm. (1 mark)
Rest of question is incomplete
4. Plantains in the field
To improve their investigation: Use random sampling, take more samples.
With the mean average question, people seemed to be getting either 10,100 or 160,000. Different answers I know but we are not sure which is right.

Rest of question is incomplete
5. Polydactyly Question
Stem cells are undifferentiated stem cells that can potentially become any cell.
Rest of question is incomplete
This question had a lot of parts to do with alleles but it was so long no one can really remember it.
6. Removing bacteria from milk with catalase.

•

Advantages: Catalysts can be reused

•

Disadvantages: Enzymes can denature, Hydrogen Peroxide doesn't kill all the bacteria

These weren't the only ones but they're the ones I have seen posted the most.

Rest of question is incomplete
7. Meiosis & Mitosis
The sperm cells were produced in the testes by Meiosis. The embryo divided by Mitosis.
For the question about the size of each cell:

1.

6.6

2.

13.2

3.

6.6

4.

3.3

Rest of question is incomplete
8. Foxes
How can scientists prove the foxes originated from the same species?
The scientists could breed 2 of the foxes and see if they produce fertile offspring. (Offspring which can reproduce)
How are the foxes different species?
Foxes, Geographical isolation. Adapted differently. Mutation, So unable to breed. Different species.
Why were the foxes on the 3 islands varied but still the same species?
The islands have similar conditions so the two species adapted similarly and were so similar they could still interbreed so were still of the same species.
I am not sure what question these answers were for)

•

Muscular tissue contracts and churns food in the stomach

•

Epithelial tissue covers the stomach

•

Glandular tissue secretes hormones and enzymes

Note: The questions may not be in the right order.

This is a mix of my answers and those of the community but they are not guaranteed to be correct.


Grade Boundary Predictions

These are completely my predictions, we have decided that it was a fairly
easy paper so our boundaries are fairly high.

A* - 46 marks

A - 37 marks

B - 31 marks

C - 24 marks




Thanks for using my mark scheme : )

Thanks this looks pretty accurate would you be able to make one for B3?x
Could you put for the disadvantage of the enzyme-cause allergies
Reply 263
There was a question, on the enzyme page ,that was like ' what is an enzyme ? '
I put that it was a biological catalyst that speeds up the rate of the reaction without being used up itself - but im not sure if that is correct!
Also , there was a question that was ' explain why the man must have heterozygous alleles for polydactyly' which was because his mother haf it and his father didnt, and it is a dominant allele so is expressed even if its just present in one pair , therefore he could only be heterozygous as he could have only obtained 1 allele of polydactyly. you could have also explained what heterozygous was but i don't know if this was needed
Reply 264
Original post by ozziess
1) 20 in total
2) 62.5m^2 in 10 quadrats
3) 20/62.5=0.32 per metre
4) 0.32*5000=1600
1600 was the actual answer

For the allele question I got:
Brown hair, brown hair
Bb, Bb
XX, XY


So if you drew a punnet square for Bb and Bb, there'd be a 25% chance that the child would have red hair, right?
What about the phenotypes and genotypes?
Original post by Adamtoo
Was there a question after the speciation one (the 5 marker)? I think I missed it -_-


Yes, it was a sole question on the back page. The question was asking why might all the islands share the same species and not all have their own species. I put something about them having roughly the same conditions/environment so the mutations that would be passed on for the ones who survived would be the same.
Reply 266
Original post by Leyak
Thanks this looks pretty accurate would you be able to make one for B3?x


I would love to but sadly I didn't do the B3 exam. I believe there are some discussions going on about it though

http://www.thestudentroom.co.uk/search-beta/?tsr-search-query=AQA+Biology+B3
Original post by Naco88
I honestly had no idea either. I just wrote B or b randomly...


Same 😂 Had no idea what it was asking me for I think I put

Parent phenotype- both brown hair
Parent genotype- homozygous and heterozygous
Gametes- Bd. Bd

Offspring genotypes- homozygous and heterozygous in some order
Pheotype- brown and red hair

Probably all wrong
Reply 268
Original post by Miz9
So if you drew a punnet square for Bb and Bb, there'd be a 25% chance that the child would have red hair, right?
What about the phenotypes and genotypes?


genotypes is what actual gene it is and phenotype is what the physical characteristic is , so isnt it something like :
Genotypes- Bb and Bb
Phenotypes- Bb Bb, bb , BB
tbh im not sure , that 5 marker was so confusing


Posted from TSR Mobile
Original post by absn7
genotypes is what actual gene it is and phenotype is what the physical characteristic is , so isnt it something like :
Genotypes- Bb and Bb
Phenotypes- Bb Bb, bb , BB
tbh im not sure , that 5 marker was so confusing


Posted from TSR Mobile


Genotype is the genetic makeup: Bb, BB, bb.
Phenotype is the expressed characteristic (what the person's hair colour is): Brown or Red, in this case.
the gametes in the questions are just B and b.

Horribly written question though...
Reply 270
Original post by absn7
genotypes is what actual gene it is and phenotype is what the physical characteristic is , so isnt it something like :
Genotypes- Bb and Bb
Phenotypes- Bb Bb, bb , BB
tbh im not sure , that 5 marker was so confusing


Posted from TSR Mobile


Yeah, that 5 marker should lower the grade boundaries seeing it's 12% of the marks.
Reply 271
Original post by Naco88
I would love to but sadly I didn't do the B3 exam. I believe there are some discussions going on about it though

http://www.thestudentroom.co.uk/search-beta/?tsr-search-query=AQA+Biology+B3


No worries thank you for the link x hope your b2 exam went well
I'm a little worried now after seeing what everyone wrote for the 6 mark question. I struggled a little on that question too, so left it till the end, and unfortunately, ran out of time too. So can anyone tell me approximately how many marks they think my answer will get me:

a) Plant the pondweed in some soil in a tub and leave it in a dark room. This is to make sure that no other factor affect (such as light shining from elsewhere) affects the rate of photosynthesis. (I know, pondweed in soil?? Makes no sense but idk why I wrote that)
b) Place the lamp in the room at a low intensity for one week.
c) Using the beaker measure, water the pondweed, however, make sure that you water the plant the same amount each time to ensure that different levels of water does not affect the rate of photosynthesis.

And that's as far as I got tbh :frown: feeling kinda down now, it was that simple and I over-complicated!
Original post by absn7
genotypes is what actual gene it is and phenotype is what the physical characteristic is , so isnt it something like :
Genotypes- Bb and Bb
Phenotypes- Bb Bb, bb , BB
tbh im not sure , that 5 marker was so confusing


Posted from TSR Mobile


no pheno type would be red hair brown hair etc. and the genotype would be Bb etc., very easy question, freee marks essentiallyt
Original post by humayra.a
I'm a little worried now after seeing what everyone wrote for the 6 mark question. I struggled a little on that question too, so left it till the end, and unfortunately, ran out of time too. So can anyone tell me approximately how many marks they think my answer will get me:

a) Plant the pondweed in some soil in a tub and leave it in a dark room. This is to make sure that no other factor affect (such as light shining from elsewhere) affects the rate of photosynthesis. (I know, pondweed in soil?? Makes no sense but idk why I wrote that)
b) Place the lamp in the room at a low intensity for one week.
c) Using the beaker measure, water the pondweed, however, make sure that you water the plant the same amount each time to ensure that different levels of water does not affect the rate of photosynthesis.

And that's as far as I got tbh :frown: feeling kinda down now, it was that simple and I over-complicated!


yeah thats wrong its to do with placing pondweed in water and measuring the amount of bubbles produced
For the 6 marker I rushed it and wrote about an iodine test for starch, which I'm guessing won't get me any marks? I realised as soon as I left the exam hall that I had screwed up
Reply 276
Original post by Adamtoo
Was there a question after the speciation one (the 5 marker)? I think I missed it -_-


Yes there was one on the page after but I believe it was only a one or two marker so I wouldn't worry too much about it
Athetle only ran for 1 minute... because the heart rate stays high after exercise
u man r gassing the athlete ran for 1.5 minutes
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???


I am an actual idiot. I thought A was a cell that had split to form B and another cell. So I thought A and B should both have 6.6 and that they were trying to trick me with the larger size *facepalm*

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