AQA AS Biology Paper 2 2025 | Exam & Mark Scheme

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I declare this is my own work.
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AS
BIOLOGY
Paper 2 N




Thursday 22 May 2025 N N N Morning Time allowed: 1 hour 30 minutes
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Materials ForNExaminer’sNUse
For this paper you must have:
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Question Mark
 a ruler with millimetre measurements
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 a scientific calculator.
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Instructions 3
 Use black ink or black ball-point pen.
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 Fill in the boxes at the top of this page.
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 Answer all questions. N N
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 You must answer the questions in the spaces provided. Do not write
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outside the box around each page or on blank pages.
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 If you need extra space for your answer(s), use the lined pages at the end of
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this book. Write the question number against your answer(s).
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 Show all your working.N N N 9
 Do all rough work in this book. Cross through any work you do not want
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TOTAL
to be marked.
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Information
 The marks for the questions are shown in brackets.
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 The maximum mark for this paper is 75.
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Answer all questions in the spaces provided.
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0 1 NFigure 1 shows the arrangement of some of the blood vessels in a mammalian circula
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tory system.
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Figure 1 N




0 1 . 1 Name the blood vessels labelled B and E in Figure 1.
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[2 marks]
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B N




E
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0 1 . 2 Give the letters of all the blood vessels shown in Figure 1 that transport
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deoxygenated blood. N


[1 mark]
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0 1 . 3 Many animals are adapted to their environments by having different types of hae
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moglobin with different tertiary structures.
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Using your knowledge of the structure of proteins, explain how different types of
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haemoglobin can have different tertiary structures.
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Question 1 continues on the next page
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Figure 2 shows the oxyhaemoglobin dissociation curve for two species of goat.
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Figure 2 N




0 1 . 4 The mountain goat lives at high altitudes where the pO2 is lower than where the domes
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tic goat lives.
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Use Figure 2 to explain how the mountain goat is adapted to living at high altitudes.
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