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A-level
BIOLOGY
Paper 3
AQA
Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
• a ruler with millimetre measurements
• a scientific calculator.
Question Mark
Instructions 1
• Use black ink or black ball-point pen.
• Fill in the boxes at the top of this page. 2
• Answer all questions in Section A.
• Answer one question from Section B.
3
• You must answer the questions in the spaces provided. Do not write outside the
box around each page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of this 4
book. Write the question number against your answer(s).
• Show all your working. 5
• Do all rough work in this book. Cross through any work you do not want to be
marked. 6
Information
7
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 78.
TOTAL
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
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*JUN217402301* IB/H/Jun21/E14 7402/3
Section A
Answer all questions in this section.
You are advised to spend no more than 1 hour and 15 minutes on this section.
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0 1 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
.1 In a population of 34 S. carolinensis, 2 had black
fur. G G C
Grey fur
C
Use the Hardy–Weinberg G B C equation to estimate how
many squirrels in this Brown-black fur population had brown-
C
black fur. Show your B B C working.
[2 marks] Black fur
C
0 1
Answer
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*02*
0 1 .2 The actual number of squirrels in this population that had brown-black fur was 16.
G
Use all of the information to calculate the actual frequency of the C allele.
Do not use the Hardy–Weinberg equation in your calculation.
Give your answer to 2 decimal places.
[1 mark]
Answer
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A-level
BIOLOGY
Paper 3
AQA
Time allowed: 2 hours
Materials
For this paper you must have: For Examiner’s Use
• a ruler with millimetre measurements
• a scientific calculator.
Question Mark
Instructions 1
• Use black ink or black ball-point pen.
• Fill in the boxes at the top of this page. 2
• Answer all questions in Section A.
• Answer one question from Section B.
3
• You must answer the questions in the spaces provided. Do not write outside the
box around each page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of this 4
book. Write the question number against your answer(s).
• Show all your working. 5
• Do all rough work in this book. Cross through any work you do not want to be
marked. 6
Information
7
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 78.
TOTAL
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
Downloaded by: academiamaster |
Distribution of this document is illegal
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2
Do not write
outside the
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*JUN217402301* IB/H/Jun21/E14 7402/3
Section A
Answer all questions in this section.
You are advised to spend no more than 1 hour and 15 minutes on this section.
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3
Do not write
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0 1 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
.1 In a population of 34 S. carolinensis, 2 had black
fur. G G C
Grey fur
C
Use the Hardy–Weinberg G B C equation to estimate how
many squirrels in this Brown-black fur population had brown-
C
black fur. Show your B B C working.
[2 marks] Black fur
C
0 1
Answer
Turn over ►
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4
Do not write
outside the
box
*02*
0 1 .2 The actual number of squirrels in this population that had brown-black fur was 16.
G
Use all of the information to calculate the actual frequency of the C allele.
Do not use the Hardy–Weinberg equation in your calculation.
Give your answer to 2 decimal places.
[1 mark]
Answer
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