AQA Biology B2 - Unofficial Mark Scheme

I hope they made the mark scheme that simple.

I believe you would get marks.

Increasing the blood flow rate happens because the blood contains haemoglobin's which carry oxygen. The muscles needs the oxygen for respiration to release energy to allow the muscles to work and contract more efficenetly, thats why the blood flow rate increases because it tries to match the demand for oxgen required by the muscles.

Thats what I wrote anyway and mentionoing lactic acid for this question is actually quite irrelevant.

↑↑↑ 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.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
c) How does the flow of the blood help the athlete's muscles?
Removes lactic acid, build up. Causes less fatigue. Supplies oxygen.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.Circle Cytoplasm. (1 mark)
What is an enzyme? (2 marks)
An enzyme is a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.Rest of question is incompleteTo 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 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.

I am not sure if the following answer was on the polydactyly question but here are our redicted answers:
Parents genotype: Genotype: mother: Bb father :Bb
Parents phenotype: Both have brown hair
Gametes: Mother: XY Father: XX
Offspring genotype: Brother: bb Sister: Bb
Offspring phenotype: Brother - red hair sister - brown hair

How do you know the man is heterogeneous?
He has B & b alleles.These weren't the only ones but they're the ones I have seen posted the most.

Rest of question is incompleteThe sperm cells were produced in the testes by Meiosis. The embryo divided by Mitosis.
For the question about the size of each cell:Rest of question is incompleteHow 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.Know more answers? Please message me on twitter @NacoRBLX, thanks!


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.

In my opinion the rate of blood flow is wrong. It increases which helps the athletes muscles because more oxygenated blood is getting to the working muscles. Therefore more oxygen is available for respiration which releases energy to be used for muscles to contract

I believe you would get marks.

Increasing the blood flow rate happens because the blood contains haemoglobin's which carry oxygen. The muscles needs the oxygen for respiration to release energy to allow the muscles to work and contract more efficenetly, thats why the blood flow rate increases because it tries to match the demand for oxgen required by the muscles.

Thats what I wrote anyway and mentionoing lactic acid for this question is actually quite irrelevant.

I wrote the exact same thing for this question, would it get full marks?

1. Athlete Question - UPDATEDa)i) Anaerobic means respiration without oxygen [1 mark]ii) The athlete was running for 1.5 minutes. [1 mark]b) How do you know it was anaerobic respiration? The athlete produced lactic acid [1 mark]c) How does the flow of the blood help the athlete's muscles? ***How does a faster rate of blood flow help him to run?***Removes lactic acid, build up. Causes less fatigue. Supplies oxygen. [4 marks]2. Pond Weed QuestionPut 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 producedNote 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 questionCircle Cytoplasm. [1 mark]What is an enzyme? [1 mark]An enzyme is a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.Muscular tissue contracts and churns food in the stomach [2 marks]Epithelial tissue covers the stomach [1 mark]Glandular tissue secretes hormones and enzymes [3 marks]Rest of question is incomplete4. Plantains in the fieldTo improve their investigation: Use random sampling, take more samples. [3 marks]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. [3 marks]Rest of question is incomplete5. Polydactyly Question - UPDATEDStem cells are undifferentiated stem cells that can potentially become any cell. [2 marks]6. Removing bacteria from milk with catalase.Advantages: Catalysts can be reused [1 mark]Disadvantages: Enzymes can denature, Hydrogen Peroxide doesn't kill all the bacteria, It could mix with/stay in the milk which could be harmful to humans.These weren't the only ones but they're the ones I have seen posted the most. [1 mark]Rest of question is incomplete7. Meiosis & MitosisThe sperm cells were produced in the testes [1 mark] by Meiosis [1 mark]. The embryo divided by Mitosis. [1 mark]For the question about the size of each cell:6.6 13.2 6.63.3 [3 marks]Rest of question is incomplete8. FoxesHow 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) [2 marks]How are the foxes different species?Foxes, Geographical isolation. Adapted differently. Mutation, So unable to breed. Different species. [5 marks]Why were the foxes on the 3 islands varied but still the same species? [1 mark]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.

That's what I wrote too- the question was quite ambiguously worded

How many marks was it worth?

4:/

Would they still give you the mark if you spelt testes wrong?