Cambridge International AS & A Level
Your text here 1
* 8 3 5 1 3 2 7 5 6 0 *
BIOLOGY 9700/42
Paper 4 A Level Structured Questions February/March 2021
2 hours
You must answer on the question paper.
No additional materials are needed.
INSTRUCTIONS
● Section A: answer all questions.
● Section B: answer one question.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.
INFORMATION
● The total mark for this paper is 100.
● The number of marks for each question or part question is shown in brackets [ ].
This document has 28 pages. Any blank pages are indicated.
DC (NF/CGW) 198769/2
© UCLES 2021 [Turn over
, 2
Section A
Answer all questions.
1 (a) The European eel, Anguilla anguilla, is a fish. The sizes of eel populations tend to remain
relatively stable despite eels producing large numbers of offspring.
Suggest two reasons why the population sizes of eels tend to remain relatively stable.
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............................................................................................................................................. [2]
(b) Explain what is meant by the general theory of evolution.
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...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(c) The generation time of a species is the mean (average) time from one generation (parents)
to the next generation (offspring). For example, the generation time of humans is about
25 years.
Fig. 1.1 shows a graph of the relationship between the rate of evolution and the generation
time for a wide range of different species.
rate of
evolution
generation time
Fig. 1.1
© UCLES 2021 9700/42/F/M/21
, 3
Describe and explain the relationship shown in Fig. 1.1.
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...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(d) The tuatara, Sphenodon punctatus, is a reptile that is native to New Zealand. It is found
nowhere else in the wild.
Fig. 1.2 shows a tuatara.
Fig. 1.2
Tuataras have a slow growth rate and can live for over one hundred years. Fossil evidence
shows that there has been little morphological change in the tuatara over the last 200 million
years. This is a much lower rate of evolution than would be expected from the generation
time of this species.
Suggest and explain why the tuatara has remained largely unchanged over the last 200
million years.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
[Total: 10]
© UCLES 2021 9700/42/F/M/21 [Turn over
Your text here 1
* 8 3 5 1 3 2 7 5 6 0 *
BIOLOGY 9700/42
Paper 4 A Level Structured Questions February/March 2021
2 hours
You must answer on the question paper.
No additional materials are needed.
INSTRUCTIONS
● Section A: answer all questions.
● Section B: answer one question.
● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs.
● Write your name, centre number and candidate number in the boxes at the top of the page.
● Write your answer to each question in the space provided.
● Do not use an erasable pen or correction fluid.
● Do not write on any bar codes.
● You may use a calculator.
● You should show all your working and use appropriate units.
INFORMATION
● The total mark for this paper is 100.
● The number of marks for each question or part question is shown in brackets [ ].
This document has 28 pages. Any blank pages are indicated.
DC (NF/CGW) 198769/2
© UCLES 2021 [Turn over
, 2
Section A
Answer all questions.
1 (a) The European eel, Anguilla anguilla, is a fish. The sizes of eel populations tend to remain
relatively stable despite eels producing large numbers of offspring.
Suggest two reasons why the population sizes of eels tend to remain relatively stable.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(b) Explain what is meant by the general theory of evolution.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [2]
(c) The generation time of a species is the mean (average) time from one generation (parents)
to the next generation (offspring). For example, the generation time of humans is about
25 years.
Fig. 1.1 shows a graph of the relationship between the rate of evolution and the generation
time for a wide range of different species.
rate of
evolution
generation time
Fig. 1.1
© UCLES 2021 9700/42/F/M/21
, 3
Describe and explain the relationship shown in Fig. 1.1.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
(d) The tuatara, Sphenodon punctatus, is a reptile that is native to New Zealand. It is found
nowhere else in the wild.
Fig. 1.2 shows a tuatara.
Fig. 1.2
Tuataras have a slow growth rate and can live for over one hundred years. Fossil evidence
shows that there has been little morphological change in the tuatara over the last 200 million
years. This is a much lower rate of evolution than would be expected from the generation
time of this species.
Suggest and explain why the tuatara has remained largely unchanged over the last 200
million years.
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
...................................................................................................................................................
............................................................................................................................................. [3]
[Total: 10]
© UCLES 2021 9700/42/F/M/21 [Turn over
