AQA A-level Biology Paper 2 2025 | Exam & Mark Scheme

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I declare this is my own work.
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A-level
BIOLOGY
Paper 2 N




Friday 13 June 2025 N N N Morning Time allowed: 2 hours
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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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2
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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to be marked.
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TOTAL
Information
 The marks for the questions are shown in brackets.
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 The maximum mark for this paper is 91.
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Answer all questions in the spaces provided.
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0 1 . 1 N In the following passage, the numbered spaces can be filled with biological terms.
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Glycolysis is the first stage of respiration. It occurs in the
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of cells and is an anaerobic proc
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ess. Glycolysis involves the
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phosphate, using ATP. The oxidation of triose phosphate to
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the net gain of ATP and reduced
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Write the correct biological term beside each number below that matches the space in th
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e passage.
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[2 marks] N




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0 1 . 2 The equation for the aerobic respiration of glucose is:
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C6H12O6 + 6 O2 N N N N N N N 6 CO2 + 6 H2O
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Six carbon dioxide molecules are produced from each glucose molecule.
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Use your knowledge of the link reaction and Krebs cycle to explain why.
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[2 marks]
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0 1 . 3 An inhibitor of the electron transfer chain was added to aerobically respiring yeast
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cells.

As aerobic respiration was inhibited, the following changes occurred:
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 oxygen uptake decreased
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 ATP production decreased
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 ethanol was produced.
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Explain the changes in the yeast cells following the addition of the inhibitor.
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[3 marks]
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Oxygen uptake decreased
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ATP production decreased
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Ethanol was produced
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Turn over for the next question
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Turn over ►
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0 2 . 1 What term is used to describe the maintenance of a stable internal environment?
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[1 mark] N




0 2 . 2 A high blood glucose concentration can cause dehydration of body cells.
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Explain why. N




Do not refer to ADH or the role of the kidneys in your answer.
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[2 marks]
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0 2 . 3 The hormone glucagon is involved in maintaining a stable blood glucose
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concentration.

Which is not a result of the action of glucagon? Tic
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k () one box.
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[1 mark]
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Activation of a protein kinase enzyme
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Activation of cyclic AMP hydrolysis
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Gluconeogenesis


Glycogenolysis




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