AQA AS Level Biology Paper 2, June 2025
Every question from AQA AS Level Biology Paper 2, June 2025 (7401): 9 questions, 75 marks, each with its mark scheme and topic.
- Question 1 8 marks
Identify blood vessels in mammalian circulation, explain differences in haemoglobin tertiary structure, and explain mountain goat adaptation using an oxyhaemoglobin dissociation curve.
Biology · 3.1 Biological molecules · 3.3 Organisms exchange substances with their environment
- Question 2 10 marks
Identify eukaryotic cell organelles and their roles in enzyme secretion, interpret a graph comparing glucose uptake mechanisms with and without oxygen, and calculate an uptake ratio.
Biology · Practical skills · 3.2 Cells · Data analysis
- Question 3 9 marks
Identify constituent elements of biological molecules, describe the emulsion test for lipids, identify an unsaturated fatty acid, and evaluate the effectiveness of cholestyramine in reducing blood cholesterol concentration.
Biology · Practical skills · 3.1 Biological molecules · Data analysis · Experimental design
- Question 4 7 marks
Calculate stomatal density from a microscopic field of view, suggest an improvement for reliability, explain a xerophytic adaptation to reduce water loss, and draw conclusions on transpiration rates from a graph.
Biology · Practical skills · 3.3 Organisms exchange substances with their environment · Experimental design · Data analysis
- Question 5 7 marks
Identify the components of ribosomes, compare the eukaryotic cell cycle with binary fission using provided tabular data, and explain the advantage of checking DNA replication accuracy.
Biology · 3.1 Biological molecules · 3.2 Cells · 3.4 Genetic information, variation and relationships between organisms
- Question 6 10 marks
Explain enzyme action using the induced-fit model, suggest safety precautions, calculate the surface area comparison of potato discs, and explain the resulting rate of reaction.
Biology · Practical skills · Required Practicals · 3.1 Biological molecules · Experimental design · Data analysis · AS practicals (1–6)
- Question 7 9 marks
Answer questions on the structure of Vibrio cholerae, protein toxin binding, the mechanism of diarrhoea via osmosis, and calculate cholera mortality from graphical data.
Biology · Practical skills · 3.1 Biological molecules · 3.2 Cells · Data analysis
- Question 8 5 marks
Explain why infections are more likely after HIV infection based on helper T cell data, and suggest and justify an aseptic technique during bacterial culture.
Biology · Required Practicals · 3.2 Cells · AS practicals (1–6)
- Question 9 10 marks
Describe how meiosis produces haploid cells and generates genetic variation, and explain how tissue fluid is formed and returned to the circulatory system.
Biology · 3.3 Organisms exchange substances with their environment · 3.4 Genetic information, variation and relationships between organisms