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I declare this is my own work.
AS
BIOLOGY
Paper 2
Thursday 22 May 2025 Morning Time allowed: 1 hour 30 minutes
Materials For Examiner’s Use
For this paper you must have:
Question Mark
• a ruler with millimetre measurements
• a scientific calculator. 1
2
Instructions 3
• Use black ink or black ball-point pen.
4
• Fill in the boxes at the top of this page.
• Answer all questions. 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). 8
• Show all your working. 9
• Do all rough work in this book. Cross through any work you do not want
TOTAL
to be marked.
Information
• The marks for the questions are shown in brackets.
• The maximum mark for this paper is 75.
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outside the
Answer all questions in the spaces provided. box
0 1 Figure 1 shows the arrangement of some of the blood vessels in a mammalian
circulatory system.
Figure 1
0 1 . 1 Name the blood vessels labelled B and E in Figure 1.
[2 marks]
B
E
0 1 . 2 Give the letters of all the blood vessels shown in Figure 1 that transport
deoxygenated blood.
[1 mark]
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0 1 . 3 Many animals are adapted to their environments by having different types of box
haemoglobin with different tertiary structures.
Using your knowledge of the structure of proteins, explain how different types of
haemoglobin can have different tertiary structures.
[3 marks]
Question 1 continues on the next page
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Figure 2 shows the oxyhaemoglobin dissociation curve for two species of goat. box
Figure 2
0 1 . 4 The mountain goat lives at high altitudes where the pO2 is lower than where the
domestic goat lives.
Use Figure 2 to explain how the mountain goat is adapted to living at high altitudes.
[2 marks]
8
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