AQA A-level BIOLOGY Paper 3
QUESTION PAPER 2021
Your text here 1
,
, 2
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 3
Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
a ruler with millimetre measurements
Question Mark
a scientific calculator.
1
Instructions 2
Use black ink or black ball-point pen. 3
Fill in the boxes at the top of this page.
4
Answer all questions in Section A.
Answer one question from Section B. 5
You must answer the questions in the spaces provided. Do not write 6
outside the box around each page or on blank pages.
7
If you need extra space for your answer(s), use the lined pages at the end of
this book. Write the question number against your answer(s). TOTAL
Show all your working.
Do all rough work in this book. Cross through any work you do not want
to be marked.
Information
The marks for the questions are shown in brackets.
The maximum mark for this paper is 78.
*02*
IB/H/Jun21/7402/3
, 3
*JUN21740230 IB/H/Jun21/E14 7402/3
Do not write
outside the
Section A box
Answer all questions in this section.
You are advised to spend no more than 1 hour and 15 minutes on this section.
In one species of squirrel, Sciurus carolinensis, fur colour is controlled by one gene,
G B
with two codominant alleles. C represents the allele for grey fur colour, and C
represents the allele for black fur colour.
Table 1 shows the three possible phenotypes.
Table 1
Genotype Phenotype
G G
C C Grey fur
G B
C C Brown-black fur
B B
C C Black fur
. 1 In a population of 34 S. carolinensis, 2 had black fur.
Use the Hardy–Weinberg equation to estimate how many squirrels in this population
had brown-black fur. Show your working.
[2 marks]
Answer
*02*
IB/H/Jun21/7402/3
QUESTION PAPER 2021
Your text here 1
,
, 2
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
A-level
BIOLOGY
Paper 3
Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
a ruler with millimetre measurements
Question Mark
a scientific calculator.
1
Instructions 2
Use black ink or black ball-point pen. 3
Fill in the boxes at the top of this page.
4
Answer all questions in Section A.
Answer one question from Section B. 5
You must answer the questions in the spaces provided. Do not write 6
outside the box around each page or on blank pages.
7
If you need extra space for your answer(s), use the lined pages at the end of
this book. Write the question number against your answer(s). TOTAL
Show all your working.
Do all rough work in this book. Cross through any work you do not want
to be marked.
Information
The marks for the questions are shown in brackets.
The maximum mark for this paper is 78.
*02*
IB/H/Jun21/7402/3
, 3
*JUN21740230 IB/H/Jun21/E14 7402/3
Do not write
outside the
Section A box
Answer all questions in this section.
You are advised to spend no more than 1 hour and 15 minutes on this section.
In one species of squirrel, Sciurus carolinensis, fur colour is controlled by one gene,
G B
with two codominant alleles. C represents the allele for grey fur colour, and C
represents the allele for black fur colour.
Table 1 shows the three possible phenotypes.
Table 1
Genotype Phenotype
G G
C C Grey fur
G B
C C Brown-black fur
B B
C C Black fur
. 1 In a population of 34 S. carolinensis, 2 had black fur.
Use the Hardy–Weinberg equation to estimate how many squirrels in this population
had brown-black fur. Show your working.
[2 marks]
Answer
*02*
IB/H/Jun21/7402/3
