AQA AS BIOLOGY Paper 2 QP 2020
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
BIOLOGY
Paper 2
Friday 22 May 2020 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a ruler with millimetre measurements
• a scientific calculator. Question Mark
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do not write 5
outside the box around each page or on blank pages.
6
• 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). 7
• Show all your working. 8
• Do all rough work in this book. Cross through any work you do not want 9
to be marked.
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 75.
*JUN207401201*
IB/M/Jun20/E15 7401/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Littorina littorea is a species of snail found on rocky sea shores.
A student investigated variation in snail shell height in two populations of snails.
Give two ways in which the student could ensure his samples would provide a reliable
measure of the variation between individuals in each population.
[2 marks]
1
2
0 1 . 2 The student could determine the median, mode and range from his measurement of
shell heights in these populations.
Give two other statistical values the student could calculate from his measurement of
shell heights in these populations.
[1 mark]
1
2
0 1 . 3 Name the taxon in the hierarchy of classification represented by:
[1 mark]
1 Littorina
2 Iittorea
*02*
IB/M/Jun20/7401/2
, 3
Do not write
outside the
0 1 . 4 The student noticed there was a difference in shell height between these populations box
of snails. He wanted to investigate if the difference was significant.
Give a suitable null hypothesis to use in his investigation and name the statistical test
to use with these data.
[2 marks]
Null hypothesis
Statistical test
6
Turn over for the next question
Turn over ►
*03*
IB/M/Jun20/7401/2
, 4
Do not write
outside the
0 2 . 1 Describe how a phosphodiester bond is formed between two nucleotides within a DNA box
molecule.
[2 marks]
0 2 . 2 The two DNA strands of a particular gene contain 168 guanine bases between them.
The relationship between the numbers of guanine bases (G), adenine bases (A),
thymine bases (T) and cytosine bases (C) in these two strands of DNA is shown in the
following equation.
G = 4(A + T) – C
Use this information and your understanding of DNA structure to calculate the
maximum number of amino acids coded by this gene.
Show your working.
[2 marks]
Answer
0 2 . 3 Name the protein associated with DNA in a chromosome.
[1 mark]
*04*
IB/M/Jun20/7401/2
Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
BIOLOGY
Paper 2
Friday 22 May 2020 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a ruler with millimetre measurements
• a scientific calculator. Question Mark
1
Instructions 2
• Use black ink or black ball-point pen.
3
• Fill in the boxes at the top of this page.
• Answer all questions. 4
• You must answer the questions in the spaces provided. Do not write 5
outside the box around each page or on blank pages.
6
• 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). 7
• Show all your working. 8
• Do all rough work in this book. Cross through any work you do not want 9
to be marked.
TOTAL
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 75.
*JUN207401201*
IB/M/Jun20/E15 7401/2
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 . 1 Littorina littorea is a species of snail found on rocky sea shores.
A student investigated variation in snail shell height in two populations of snails.
Give two ways in which the student could ensure his samples would provide a reliable
measure of the variation between individuals in each population.
[2 marks]
1
2
0 1 . 2 The student could determine the median, mode and range from his measurement of
shell heights in these populations.
Give two other statistical values the student could calculate from his measurement of
shell heights in these populations.
[1 mark]
1
2
0 1 . 3 Name the taxon in the hierarchy of classification represented by:
[1 mark]
1 Littorina
2 Iittorea
*02*
IB/M/Jun20/7401/2
, 3
Do not write
outside the
0 1 . 4 The student noticed there was a difference in shell height between these populations box
of snails. He wanted to investigate if the difference was significant.
Give a suitable null hypothesis to use in his investigation and name the statistical test
to use with these data.
[2 marks]
Null hypothesis
Statistical test
6
Turn over for the next question
Turn over ►
*03*
IB/M/Jun20/7401/2
, 4
Do not write
outside the
0 2 . 1 Describe how a phosphodiester bond is formed between two nucleotides within a DNA box
molecule.
[2 marks]
0 2 . 2 The two DNA strands of a particular gene contain 168 guanine bases between them.
The relationship between the numbers of guanine bases (G), adenine bases (A),
thymine bases (T) and cytosine bases (C) in these two strands of DNA is shown in the
following equation.
G = 4(A + T) – C
Use this information and your understanding of DNA structure to calculate the
maximum number of amino acids coded by this gene.
Show your working.
[2 marks]
Answer
0 2 . 3 Name the protein associated with DNA in a chromosome.
[1 mark]
*04*
IB/M/Jun20/7401/2
