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AQA A-Level Biology (7402): complete guide to the 8 topics and the exams

A complete guide to AQA A-Level Biology (specification 7402). Covers all eight topics (3.1-3.8), how the three written papers are structured and marked, the required practicals and maths skills, and how to study each topic for top grades.

Browse guides →Syllabus dot points (46)

AQA A-Level Biology (specification 7402) is a two-year linear course assessed by three written papers at the end of Year 13. There is no coursework grade; practical work is reported separately as the Practical Endorsement. This page is the index: below is a topic-by-topic map of the eight content areas, the exam structure, and how to study each one.

The eight AQA Biology topics (3.1-3.8)

The specification splits the subject content into eight numbered topics. The first four are the molecular and cellular foundation; the last four scale up to organisms, populations and gene control.

3.1 Biological molecules
The chemistry that underpins everything else: carbohydrates, lipids, proteins and enzymes, DNA and RNA, ATP, water and inorganic ions. Includes the biochemical food tests. Start here - later topics assume it.
3.2 Cells
Cell structure (eukaryotic and prokaryotic), the cell cycle and mitosis, transport across membranes (diffusion, osmosis, active transport), and the immune system including antibodies and vaccination.
3.3 Organisms exchange substances with their environment
Surface-area-to-volume ratio, gas exchange in single-celled organisms, insects, fish and plants, digestion and absorption, and mass transport in animals (the heart, haemoglobin) and plants (xylem and phloem).
3.4 Genetic information, variation and relationships between organisms
DNA, genes and protein synthesis (transcription and translation), the genetic code, meiosis and genetic diversity, classification and phylogeny, biodiversity and investigating it.
3.5 Energy transfers in and between organisms
Photosynthesis and respiration (the detailed biochemistry), energy and biomass transfer through ecosystems, and the nutrient cycles (carbon and nitrogen).
3.6 Organisms respond to changes in their environments
Receptors, nervous coordination (the nerve impulse and synapses), muscle contraction, and homeostasis (control of blood glucose, water potential and temperature).
3.7 Genetics, populations, evolution and ecosystems
Inheritance, the Hardy-Weinberg principle, natural selection and speciation, populations in ecosystems, and succession.
3.8 The control of gene expression
Gene mutation, stem cells, the control of transcription and translation (including epigenetics), and gene technologies (PCR, gene editing, DNA probes, recombinant DNA).

Exam structure

AQA A-Level Biology is assessed by three written papers, all sat at the end of the course. A calculator is allowed in every paper.

  • Paper 1 - topics 3.1-3.4 and relevant practical skills. 2 hours, 91 marks, 35% of the A-Level. A mix of short answers, longer structured questions, and one 15-mark extended-response question.
  • Paper 2 - topics 3.5-3.8 and relevant practical skills. 2 hours, 91 marks, 35%. Same style as Paper 1.
  • Paper 3 - any content from all eight topics. 2 hours, 78 marks, 30%. Structured questions, a critical-analysis section on experimental data, and one 25-mark synoptic essay (choose one of two titles).

At least 10% of marks assess maths skills, and around 15% assess practical skills drawn from the 12 required practicals.

How to study AQA Biology

Biology rewards precise factual mastery plus the ability to apply it to unfamiliar contexts.

  1. Work from the specification statements. Each numbered point (e.g. 3.1.2 carbohydrates) is a checklist; questions are written from them. Turn each statement into a flashcard.
  2. Learn definitions exactly. Mark schemes award marks for precise wording (e.g. "condensation reaction", "glycosidic bond", "complementary tertiary structure").
  3. Master the biochemical tests and required practicals. The food tests (Benedict's, iodine, emulsion, biuret) and the 12 practicals appear repeatedly across all three papers.
  4. Drill application and data questions. Paper 3 especially rewards interpreting unfamiliar graphs and experiments. Practise these weekly from the start of Year 13.
  5. Plan essays. The 25-mark Paper 3 essay is synoptic - practise linking a theme (e.g. "the importance of water" or "the importance of proteins") across several topics.

Topic 3.1 dot points

For specification-statement-level coverage of 3.1 Biological molecules, each topic has its own focused answer page with worked exam questions and cross-links:

  • Carbohydrates - monosaccharides, disaccharides, polysaccharides and the reducing-sugar and starch tests.
  • Lipids - triglycerides, phospholipids, ester bonds and the emulsion test.
  • Proteins - amino acids, the four levels of structure, the peptide bond and the biuret test.

Browse the full set at /a-level-aqa/biology/syllabus.

For the official specification

AQA publishes the full specification (7402), past papers, mark schemes and the required-practical handbook at aqa.org.uk. Always revise from the current specification and AQA's own past papers, because the question style and the Paper 3 essay format are board-specific.

Biology guides

In-depth written guides with paired practice quizzes.

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Biology practice quizzes

Multiple-choice drills with worked answer explanations. Your scores stay on this device.

The A-LEVEL-AQA system, explained

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Common questions about Biology

How is AQA A-Level Biology (7402) structured?
AQA A-Level Biology is a two-year linear course assessed entirely by three written exams at the end of Year 13. The subject content is organised into eight topics (3.1 to 3.8) plus 12 required practicals and a set of mathematical skills. Topics 3.1 to 3.4 are broadly molecular and cellular biology; 3.5 to 3.8 build to whole-organism, ecology and gene-level biology. There is no coursework grade, but practical competence is separately reported as a Practical Endorsement (pass or not classified).
What are the three AQA A-Level Biology exam papers?
Paper 1 covers topics 3.1 to 3.4 plus relevant practical skills (2 hours, 91 marks, 35% of the A-Level). Paper 2 covers topics 3.5 to 3.8 plus relevant practical skills (2 hours, 91 marks, 35%). Paper 3 covers any content across all eight topics, with structured questions, a critical-analysis section and a 25-mark extended essay (2 hours, 78 marks, 30%). Each paper includes short answers, longer calculation and data questions, and extended prose.
What maths skills does AQA A-Level Biology require?
At least 10% of the marks across the papers assess mathematical skills at Level 2 (roughly GCSE higher tier and above). Expect ratios and percentages, standard form, logarithms (for pH and population growth), magnification and scale calculations, surface-area-to-volume ratios, statistical tests (standard deviation, the chi-squared test, the Student t-test and correlation coefficients), and reading and plotting graphs. A calculator is allowed in every paper.
What are the required practicals and the Practical Endorsement?
There are 12 required practicals (for example enzyme rates, water potential of plant tissue, dissection, chromatography, and field-sampling techniques). They are not directly examined in a lab, but around 15% of written-exam marks test practical skills and the methods of these specific practicals. Separately, your teacher assesses your hands-on competence against five Common Practical Assessment Criteria; passing earns the Practical Endorsement reported alongside your grade.
How should I structure my AQA A-Level Biology revision?
Work topic by topic against the specification statements (3.1.1, 3.1.2, and so on), because exam questions are written directly from them. For each statement, learn the definitions precisely, then practise applying them to unfamiliar data and contexts, since Paper 3 in particular rewards application over recall. Memorise the biochemical tests, the named structures, and the required-practical methods, and drill past-paper extended-response and essay questions from the start of Year 13.
How does AQA A-Level Biology compare to other exam boards?
All A-Level Biology specifications (AQA, OCR, Edexcel, Eduqas) cover the same core regulated content, so a topic such as biological molecules is broadly the same everywhere. AQA's distinctive features are the topic numbering (3.1-3.8), the synoptic 25-mark essay in Paper 3, and its specific list of 12 required practicals. Always revise from the AQA specification and AQA past papers, because question style and the essay format are board-specific.
What's the difference between mitosis and meiosis?
Mitosis produces two identical diploid cells (for growth and repair). Meiosis produces four genetically distinct haploid cells (for sexual reproduction).
How does protein synthesis work?
Transcription (DNA → mRNA in the nucleus) then translation (mRNA → polypeptide at the ribosome). tRNA brings amino acids that the ribosome links into the protein sequence the mRNA codes for.
What's homeostasis?
The maintenance of a stable internal environment (temperature, blood glucose, pH) despite external change — usually via negative feedback loops involving receptors, control centres, and effectors.
How does evolution by natural selection work?
Variation exists in a population → some variants survive and reproduce better in a given environment → those traits become more common over generations. Requires heritable variation, differential reproductive success, and time.
What's the difference between an antibody and an antigen?
Antigen: a molecule (often on a pathogen) that triggers an immune response. Antibody: a Y-shaped protein the immune system makes to bind specifically to that antigen.