Edexcel B3 unofficial markscheme 19th June 2017

50% is the correct answer, as we are assuming that the sex was male, the chance of inheritence is 50% rather than 25%.

what was the 3 mark calculation?

Everyone in my school got 24 but to be honest, they didn't make it clear as to whether the 0.925% and 0.625% was of the entire 16,000 or out of the two 8,000 groups

I wouldn't be surprised if both 48 and 24 are accepted, the question was not the best worded.

What did people get for the punnett square question?

I got 48 people

I used the total to work out the percentage of the total and got 100 or one and 148 for the other. 148-100= 48

Did anyone else do this?

Here is the long awaited markscheme. I think the grade boundaries will be pretty low but overall I think personally I did okay – Please remember you can bring up your grade with the other exams and don’t worry if you get wrong answers! Feel free to add to the markscheme below as I can’t remember all the questions. Good luck!

1a. Species 1 because the nectar is at the top

1b. Option D

1c. Co-evolution: As one species evolves the other devolves so moth becomes deformed so its proboscis shrinks so co-evolution benefits the orchid, not the moth

2a. Dominant allele = Male Recessive allele = Female OR Isotope monitor

Classical conditioning

Put a flag in front of horse to habituate it

38 HIV

Vegetarian cheese à use restriction enzyme to combine milk together to make it yellow and clot to form cheese and then put it into a fermenter

Lactose free-milk à Normal milk + sieve + barium nitrate, so lactose is extracted. Include conditions of pH, temperature and contamination

are you sure because I put 25%, others are saying 50%

Here is the long awaited markscheme. I think the grade boundaries will be pretty low but overall I think personally I did okay – Please remember you can bring up your grade with the other exams and don’t worry if you get wrong answers! Feel free to add to the markscheme below as I can’t remember all the questions. Good luck!

1a. Species 1 because the nectar is at the top

1b. Option D

1c. Co-evolution: As one species evolves the other devolves so moth becomes deformed so its proboscis shrinks so co-evolution benefits the orchid, not the moth

2a. Dominant allele = Male Recessive allele = Female OR Isotope monitor

Classical conditioning

Put a flag in front of horse to habituate it

38 HIV

Vegetarian cheese à use restriction enzyme to combine milk together to make it yellow and clot to form cheese and then put it into a fermenter

Lactose free-milk à Normal milk + sieve + barium nitrate, so lactose is extracted. Include conditions of pH, temperature and contamination

its 50% because it was only to do with the male not male and female
i put 25% though :/

I originally got 25% but it said the chance of having a 'boy with haemophilia' which was 50%. One boy with no traces of it and one boy with it.

mate, it says the expirement is split in half between 16000 people; so its 8000 each.

What did you guys say about the butterflies laying eggs under the leaves???