AQA Biology B2 - Unofficial Mark Scheme

Scroll to see replies

It's not: remember, they're using different units. m is a unit of length while m² is a unit of area. I'll admit it seems weird with decimals, but you've just got to accept they're completely different measurements.

makes so much more sense thank you, any idea how many marks I'd get out of 3, if any, if I just did 25x25x10 divide by 100, my end answer was 1600

Reply 221

WrightKe

Original post by Certified

Process in the image was Meiosis. The zygote divides many times by mitosis to form an embryo (which is what the bottom question asked).

Silly me, Thanks!

Reply 222

jazz_xox_

Original post by poseidons

How did everyone work out question 7 where we had to work out the picograms for each cell in the division, starting with 6.6 picograms?

So it was the process of meiosis,
First, the chromosomes doubled (so 6.6 x 2 =13.2)
Then they divide once (13.2 / 2 = 6.6)
Then they divide for a second time (6.6 / 2 = 3.3)

Reply 223

AK45HSR

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

These weren't the only ones but are 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:

6.6

13.2

6.6

3.3

Rest of question is incomplete

8. Foxes

Foxes, Geographical isolation. Adapted differently. Mutation, So unable to breed. Different species.
Why were the foxes on the 3 islands varies 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 : )

I though 6 disadvantage was because hydrogen peroxide doesn't kill all the bacteria (100% certain it said that)

Reply 224

Adamtoo

Enzymes are biological catalysts that are made up of proteins right? Idk if I got 1 or 2 marks for that.

Reply 225

missn2000

for the first question I put anaerobic means without oxygen is that right ?

(edited 7 years ago)

Reply 226

m_______eg.m

Original post by RevisionGuide

Tissues
What is the function of glandular tissue in the stomach? (2 marks)
What is the function of muscular tissue in the stomach?
What is the function of epithelial tissue in the stomach?

Quadrat Question
What is the area of the field
What was the mean of plantain
What was the total area of the 10 Quadrats

6 Marker
How can you use the following apparatus (lamp, pondweed, beaker and ruler) to test light intensity?

I think the quadrat question answers where:

The area of field:5000
Mean of plantain:2
Total area of field:250m2^
I think I'm not 100% sure

Reply 227

poseidons

Okay definite answer for quadrant:

We are told the each quadrant is 25cm by 25cm
This means that the area is 0.25m x 0.25m = 0.0625m^2

The table added up to 20 plants across the 10 quadrants
20/10 = 2 plants per quadrant

2 / 0.0625 = 32 plants per square metre

100m x 50m = 5000m^2 size of field

32 plants per m^2 multiplied by 5000m^2 is 160,000 plants in total

Reply 228

m_______eg.m

Original post by missn2000

for the fifrst question I put anaerobi means without oxyden is that right ?

Yes I think so

Reply 229

jazz_xox_

Original post by louisaah

does anyone know the answers to that hair question... i literally guessed that lol i have never seen genotypes ever in my revision book bUT ITS 5 MARKS I can't believe myself

The parents both had Bb alles, as they both had brown hair, but both passed down a b allele to their daughter, who had red hair - caused by a recessive allele.

I used a punnet square to calculate the outcomes which turned out to be 3:1, brown:red.

Genotypes: BB, Bb, Bb, bb (actually think i wrote these down wrong)
Phenotypes: brown, brown, brown, red

so 25% chance of having red hair, which answers the question 'Show how this couple could produce a child with red hair)

Reply 230

Naco88

Original post by Blahblahblah7

I though 6 disadvantage was because hydrogen peroxide doesn't kill all the bacteria (100% certain it said that)

Thanks i'll add it in.

Reply 231

adamhulme_

Original post by Naco88

5. Polydactyly Question

One of the questions was explain why he is heterozygous so:
As his father didnt have polydactly, and polydactyly alleles are dominant, both of his fathers alleles are the non-polydactly ones, or (pp).
His mother must have a polydactly allele, as she has it herself.
The child has polydactly, as we are told in the question and therefore must be heterozygous as he must have recieved the polydactyly (P) allele from his mother, but can only recieve the non-polydactyly (p) allele from his father making him (Pp) or heterozygous.

Reply 232

jazz_xox_

Original post by poseidons

I read this as the number per quadrat, not per m2. :frown:

for the third mark do you think they would credit it for your answer for part B?

Reply 233

jazz_xox_

Original post by Adamtoo

Enzymes are biological catalysts that are made up of proteins right? Idk if I got 1 or 2 marks for that.

pretty sure this would be 2 marks, one for protein, one for biological catalyst

Reply 234

m_______eg.m

Gene diagram question-
Man=red hair
Sister and parents=brown hair
Brown hair is dominant allele B

Parents:
Phenotype- brown. Brown
Genotype- Bb. Bb
Alleles- B. b. B. b

Children-
Genotype- BB. Bb. Bb. bb
Phenotype-brown:red
3:1

Reply 235

poseidons

Original post by jazz_xox_

I read this as the number per quadrat, not per m2. :frown:

for the third mark do you think they would credit it for your answer for part B?

Think 3 marks would need to be absolutely everything correct, 2 for one part wrong

Reply 236

JakeHorsey

Original post by jazz_xox_

Does anyone think the athlete ran for 1 minute because the blood flow stopped increases after this, and it stayed level to repay oxygen debt? :s-smilie:

That did go through my mind but I just stuck to my guns thinking his heart rate had stayed at a point where it could maintain enough blood flow to keep him going at an appropriate speed (as a warmup would).