AQA A LEVEL BIOLOGY PAPER 2
LATEST 2026/2027 EXAM UPDATE
QUESTIONS AND ANSWERS
AQA A Level Biology | Key Domains: Energy Transfers, Organisms Respond to Changes,
Genetics, Populations, Evolution and Ecosystems, Gene Expression, Control of Gene Expression
80 Questions/Items | Expert-Aligned Structure | A-Level Exam Format
April 2026
,Abstract
This AQA A Level Biology Paper 2 practice examination for 2026/2027 presents eighty exam-style
questions with correct answers and detailed rationales. The examination covers the advanced biological
concepts specified in the AQA A Level Biology specification for Paper 2, including energy transfer
mechanisms in respiration and photosynthesis, nervous coordination and muscle function, homeostasis,
genetics and inheritance, populations and evolution, gene expression and DNA technology, epigenetics,
and control of gene expression. Each question is accompanied by a rationale explaining the underlying
biological principle, the appropriate experimental methodology, and the reasoning for eliminating
incorrect options. This resource is designed to support students in applying knowledge to complex
scenarios, interpreting experimental data, and developing the analytical skills essential for success on the
AQA A Level Biology examination.
Keywords: AQA A Level Biology, Paper 2, respiration, photosynthesis, nervous system, homeostasis,
genetics, evolution, gene expression, epigenetics, DNA technology, Hardy-Weinberg, ATP synthesis,
muscle contraction, osmoregulation
1. Exam Structure Overview
The following table outlines the distribution of the 80 questions across the seven key sections covered in this AQA A
Level Biology Paper 2 practice examination. Questions are designed to reflect the relative emphasis of each topic
area in the AQA specification and include multiple-choice, short-answer, and synoptic extended-response formats.
Section Topic Area Questions
1 Energy Transfers (Respiration and Photosynthesis) 1-15
2 Organisms Respond to Changes (Nervous, Muscles, Homeostasis) 16-30
3 Genetics, Populations, Evolution and Ecosystems 31-45
4 Gene Expression and DNA Technology 46-60
5 Control of Gene Expression 61-70
6 Data Analysis and Experimental Skills 71-76
7 Synoptic and Extended Response 77-80
Total 80
Table 1. Question Distribution Across Examination Sections
2. Practice Examination: Questions, Answers, and Rationales
The following section presents all eighty questions organised by topic section. Correct answers are displayed in bold
cyan text. Each question includes a detailed rationale explaining the biological principle, experimental basis, and
reasoning for eliminating incorrect alternatives.
, 2.1 Section 1: Energy Transfers in Organisms (Respiration and Photosynthesis)
1. During oxidative phosphorylation, the final electron acceptor is:
A. A. Oxygen
B. B. NAD+
C. C. Water
D. D. Carbon dioxide
Rationale: Oxygen (O2) is the terminal electron acceptor in the mitochondrial electron transport chain (ETC). Electrons from
NADH and FADH2 pass through complexes I-IV and are ultimately transferred to molecular oxygen, which combines with
protons to form water. Without oxygen, the ETC cannot operate, leading to a backlog of NADH/FADH2 and cessation of
ATP synthesis via chemiosmosis.
2. Which stage of aerobic respiration produces the most ATP molecules per glucose molecule?
A. A. Glycolysis
B. B. Link reaction
C. C. Krebs cycle
D. D. Oxidative phosphorylation
Rationale: Oxidative phosphorylation produces approximately 28-34 ATP per glucose molecule (depending on shuttle
efficiency), compared to a net 2 ATP from glycolysis and 2 GTP (equivalent to ATP) directly from the Krebs cycle. The
proton gradient established by the ETC drives ATP synthase, making oxidative phosphorylation by far the most productive
stage.
3. The chemiosmotic theory explains ATP synthesis during respiration. Which component is essential for establishing
the proton gradient?
A. A. ATP synthase activity alone
B. B. The inner mitochondrial membrane impermeability to protons
C. C. Glycolytic enzymes in the cytoplasm
D. D. Oxygen binding to haemoglobin
Rationale: The inner mitochondrial membrane's impermeability to protons (H+ ions) is fundamental to the chemiosmotic
theory. As electrons flow through ETC complexes I, III, and IV, protons are pumped from the mitochondrial matrix into the
intermembrane space, creating an electrochemical gradient (proton motive force). This gradient drives protons back through
ATP synthase, coupling the flow to ATP production.
4. In the light-dependent stage of photosynthesis, water is split. What are the products of this photolysis?
A. A. Oxygen and ATP
B. B. Oxygen, protons, and electrons
C. C. Carbon dioxide and hydrogen
D. D. Glucose and water
Rationale: Photolysis of water occurs at photosystem II (PSII), where light energy splits water molecules into oxygen (waste
product released as gas), protons (contributing to the proton gradient across the thylakoid membrane), and electrons (which
replace those lost by the oxidised P680 chlorophyll). The equation: 2H2O -> 4H+ + 4e- + O2.
5. Which pigment absorbs light primarily in the red and blue wavelengths of the visible spectrum?
A. A. Carotenoids
B. B. Xanthophyll
LATEST 2026/2027 EXAM UPDATE
QUESTIONS AND ANSWERS
AQA A Level Biology | Key Domains: Energy Transfers, Organisms Respond to Changes,
Genetics, Populations, Evolution and Ecosystems, Gene Expression, Control of Gene Expression
80 Questions/Items | Expert-Aligned Structure | A-Level Exam Format
April 2026
,Abstract
This AQA A Level Biology Paper 2 practice examination for 2026/2027 presents eighty exam-style
questions with correct answers and detailed rationales. The examination covers the advanced biological
concepts specified in the AQA A Level Biology specification for Paper 2, including energy transfer
mechanisms in respiration and photosynthesis, nervous coordination and muscle function, homeostasis,
genetics and inheritance, populations and evolution, gene expression and DNA technology, epigenetics,
and control of gene expression. Each question is accompanied by a rationale explaining the underlying
biological principle, the appropriate experimental methodology, and the reasoning for eliminating
incorrect options. This resource is designed to support students in applying knowledge to complex
scenarios, interpreting experimental data, and developing the analytical skills essential for success on the
AQA A Level Biology examination.
Keywords: AQA A Level Biology, Paper 2, respiration, photosynthesis, nervous system, homeostasis,
genetics, evolution, gene expression, epigenetics, DNA technology, Hardy-Weinberg, ATP synthesis,
muscle contraction, osmoregulation
1. Exam Structure Overview
The following table outlines the distribution of the 80 questions across the seven key sections covered in this AQA A
Level Biology Paper 2 practice examination. Questions are designed to reflect the relative emphasis of each topic
area in the AQA specification and include multiple-choice, short-answer, and synoptic extended-response formats.
Section Topic Area Questions
1 Energy Transfers (Respiration and Photosynthesis) 1-15
2 Organisms Respond to Changes (Nervous, Muscles, Homeostasis) 16-30
3 Genetics, Populations, Evolution and Ecosystems 31-45
4 Gene Expression and DNA Technology 46-60
5 Control of Gene Expression 61-70
6 Data Analysis and Experimental Skills 71-76
7 Synoptic and Extended Response 77-80
Total 80
Table 1. Question Distribution Across Examination Sections
2. Practice Examination: Questions, Answers, and Rationales
The following section presents all eighty questions organised by topic section. Correct answers are displayed in bold
cyan text. Each question includes a detailed rationale explaining the biological principle, experimental basis, and
reasoning for eliminating incorrect alternatives.
, 2.1 Section 1: Energy Transfers in Organisms (Respiration and Photosynthesis)
1. During oxidative phosphorylation, the final electron acceptor is:
A. A. Oxygen
B. B. NAD+
C. C. Water
D. D. Carbon dioxide
Rationale: Oxygen (O2) is the terminal electron acceptor in the mitochondrial electron transport chain (ETC). Electrons from
NADH and FADH2 pass through complexes I-IV and are ultimately transferred to molecular oxygen, which combines with
protons to form water. Without oxygen, the ETC cannot operate, leading to a backlog of NADH/FADH2 and cessation of
ATP synthesis via chemiosmosis.
2. Which stage of aerobic respiration produces the most ATP molecules per glucose molecule?
A. A. Glycolysis
B. B. Link reaction
C. C. Krebs cycle
D. D. Oxidative phosphorylation
Rationale: Oxidative phosphorylation produces approximately 28-34 ATP per glucose molecule (depending on shuttle
efficiency), compared to a net 2 ATP from glycolysis and 2 GTP (equivalent to ATP) directly from the Krebs cycle. The
proton gradient established by the ETC drives ATP synthase, making oxidative phosphorylation by far the most productive
stage.
3. The chemiosmotic theory explains ATP synthesis during respiration. Which component is essential for establishing
the proton gradient?
A. A. ATP synthase activity alone
B. B. The inner mitochondrial membrane impermeability to protons
C. C. Glycolytic enzymes in the cytoplasm
D. D. Oxygen binding to haemoglobin
Rationale: The inner mitochondrial membrane's impermeability to protons (H+ ions) is fundamental to the chemiosmotic
theory. As electrons flow through ETC complexes I, III, and IV, protons are pumped from the mitochondrial matrix into the
intermembrane space, creating an electrochemical gradient (proton motive force). This gradient drives protons back through
ATP synthase, coupling the flow to ATP production.
4. In the light-dependent stage of photosynthesis, water is split. What are the products of this photolysis?
A. A. Oxygen and ATP
B. B. Oxygen, protons, and electrons
C. C. Carbon dioxide and hydrogen
D. D. Glucose and water
Rationale: Photolysis of water occurs at photosystem II (PSII), where light energy splits water molecules into oxygen (waste
product released as gas), protons (contributing to the proton gradient across the thylakoid membrane), and electrons (which
replace those lost by the oxidised P680 chlorophyll). The equation: 2H2O -> 4H+ + 4e- + O2.
5. Which pigment absorbs light primarily in the red and blue wavelengths of the visible spectrum?
A. A. Carotenoids
B. B. Xanthophyll
