A-Level Biology Specification Guide – Every Exam Board Explained
A clear guide to the structure of every A-Level Biology specification – AQA, OCR, Edexcel, Edexcel International, WJEC and Eduqas – what each paper covers, and how to use yours as a revision checklist.
Last updated: February 2026
Understanding Your A-Level Biology Specification
Your specification is the single most important document in your A-Level Biology course – and most students never read it. It tells you exactly what you will be examined on, how the papers are structured, how the marks are split, and what practical and mathematical skills you need. Knowing your specification inside out is one of the simplest ways to stop wasting revision time on content that won’t come up, and to make sure you cover everything that will.
This guide breaks down the structure of every major A-Level Biology specification – AQA, OCR A, OCR B, Edexcel A (Salters-Nuffield), Edexcel B, Edexcel International, WJEC and Eduqas – so you can see at a glance how your course is organised, how it is assessed, and how to use the spec as a revision checklist. Whichever board you’re on, the principle is the same: the specification is your map.
AQA A-Level Biology (7402)
AQA is the largest A-Level Biology specification. The content is divided into eight topics, the first four taught in Year 1 (AS) and the last four added in Year 2 (A-level only).
- 3.1 Biological molecules
- 3.2 Cells
- 3.3 Organisms exchange substances with their environment
- 3.4 Genetic information, variation and relationships between organisms
- 3.5 Energy transfers in and between organisms (A-level only)
- 3.6 Organisms respond to changes in their environments (A-level only)
- 3.7 Genetics, populations, evolution and ecosystems (A-level only)
- 3.8 The control of gene expression (A-level only)
OCR A – Biology A (H420)
OCR A organises content into six modules, with Module 1 (practical skills) running throughout.
- Module 1 – Development of practical skills in biology
- Module 2 – Foundations in biology
- Module 3 – Exchange and transport
- Module 4 – Biodiversity, evolution and disease
- Module 5 – Communication, homeostasis and energy
- Module 6 – Genetics, evolution and ecosystems
OCR B – Biology B (Advancing Biology, H422)
OCR B (“Advancing Biology”) takes a context-led, narrative approach – the same biology is taught through real-world stories and applications. Content is organised into six modules (with Module 1 as practical skills), but framed around themes such as communication, energy and biodiversity. The assessment structure mirrors OCR A: three written components, with the third being synoptic.
Edexcel A (Salters-Nuffield, 9BN0) & Edexcel B (9BI0)
Pearson Edexcel offers two A-Level Biology specifications:
Edexcel A (Salters-Nuffield / SNAB) is context-led, organised into 10 topics taught through real-life contexts (e.g. “Lifestyle, Health and Risk”, “Run for your Life”). Assessment is three papers, each 2 hours, 100 marks, 33.33%, plus the Science Practical Endorsement based on 18 core practicals.
Edexcel B (9BI0) is a more conventional, concept-led specification, also assessed by three papers of similar weighting. It uniquely requires some detail other boards don’t (for example, naming DNA ligase).
Edexcel International A-Level Biology (IAL, YBI11)
Taken by students outside the UK (and at some international centres), the Pearson Edexcel International Advanced Level in Biology is structured as six units, allowing staged assessment across International AS (IAS) and International A2 (IA2):
- Unit 1 – Molecules, Diet, Transport and Health
- Unit 2 – Cells, Development, Biodiversity and Conservation
- Unit 3 – Practical Skills in Biology I (a written practical-skills paper)
- Unit 4 – Energy, Environment, Microbiology and Immunity
- Unit 5 – Respiration, Internal Environment, Coordination and Gene Technology
- Unit 6 – Practical Skills in Biology II (a written practical-skills paper)
WJEC & Eduqas A-Level Biology
WJEC and Eduqas share almost identical content but are different qualifications: WJEC is the Welsh board (and the default in Wales), while Eduqas is WJEC’s England-facing brand, graded on the standard A*–E scale.
WJEC is divided into 5 units (2 AS units + 3 A2 units). Notably, Unit 5 includes internally assessed practical work (an Experimental Task and a Practical Analysis Task).
Eduqas is assessed by three written components, each 2 hours, 100 marks, worth 33⅓% of the qualification, plus a separate practical endorsement.
What Each Exam Paper Actually Covers
Knowing which paper tests which content is one of the most useful things the specification tells you – it stops you walking into Paper 2 having only revised the Year 1 topics. Here is how the content is split across the papers for the main boards.
| Board | Paper 1 | Paper 2 | Paper 3 |
|---|---|---|---|
| AQA (7402) | Topics 1–4 (+ practical skills) | Topics 5–8 (+ practical skills) | All topics 1–8 + a 25-mark synoptic essay |
| OCR A (H420) | Biological processes (Modules 1,2,3,5) | Biological diversity (Modules 1,2,4,6) | Unified biology – synoptic, all modules |
| Edexcel A (SNAB) | The Natural Environment & Species Survival (Topics 1–4,6) | Energy, Exercise & Co-ordination (Topics 1–4,7,8) | General & Practical Applications – synoptic + practicals |
| Eduqas | Energy for Life (Component 1) | Continuity of Life (Component 2) | Requirements for Life – synoptic (Component 3) |
What Each Topic Covers – AQA Worked Example
Specifications are written as a long list of statements, which can feel overwhelming. It helps to see the big shape first. Here is what each AQA topic actually contains – the other boards cover very similar biology under different headings.
| Topic | What it covers | Year |
|---|---|---|
| 3.1 Biological molecules | Carbohydrates, lipids, proteins, enzymes, nucleic acids, ATP, water and inorganic ions | 1 (AS) |
| 3.2 Cells | Cell structure, the cell cycle and mitosis, transport across membranes, the immune system | 1 (AS) |
| 3.3 Exchange | Surface area to volume, gas exchange, digestion and absorption, mass transport in animals and plants | 1 (AS) |
| 3.4 Genetic information | DNA and RNA, DNA replication, protein synthesis, genetic diversity, biodiversity and classification | 1 (AS) |
| 3.5 Energy transfers | Photosynthesis, respiration, energy and ecosystems, nutrient cycles | 2 (A-level) |
| 3.6 Responding to change | Stimuli and responses, nervous coordination, muscles, homeostasis (blood glucose, kidney) | 2 (A-level) |
| 3.7 Genetics & populations | Inheritance, populations and evolution (Hardy–Weinberg, natural selection, speciation), ecosystems | 2 (A-level) |
| 3.8 Control of gene expression | Gene mutations, stem cells, regulation of transcription/translation, epigenetics, cancer, gene technology | 2 (A-level) |
Turning a Spec Statement Into Revision – A Worked Example
This is the technique that turns the specification from a wall of text into a working revision system. Take a single specification statement and break it down.
The statement (AQA 3.1.4.2): “The induced-fit model of enzyme action. The mechanism of enzyme action… the lowering of activation energy.”
How to Use Your Specification as a Revision Tool
Whatever your board, here is how to turn the specification into a working revision system:
Not Sure What Your Specification Actually Requires?
As a former examiner for WJEC/Eduqas and Edexcel, I know these specifications inside out – what each one demands, where they differ, and exactly what examiners look for. If you’re unsure what to revise, tutoring will turn your specification into a clear, manageable plan.
Tyrone John • CBiol MRSB • Former WJEC/Eduqas & Edexcel Examiner • 25+ Years Teaching A-Level Biology
Book a Free ConsultationFrequently Asked Questions
How many topics or modules are in A-Level Biology?
It depends on your board. AQA has eight topics (3.1 to 3.8). OCR A and OCR B have six modules each. Edexcel A (Salters-Nuffield) has ten context-led topics. WJEC is divided into five units (two AS and three A2). Eduqas is assessed across three components. Although the structure differs, the underlying biology is very similar across all boards.
How is A-Level Biology assessed?
Almost all UK A-Level Biology specifications are assessed by three written papers taken at the end of Year 2, plus a separate Practical Endorsement (a pass/fail assessment of laboratory skills based on a set of required or core practicals). For AQA each paper is 2 hours and 91 marks; for OCR A the papers are 100, 100 and 70 marks; for Edexcel A and Eduqas each paper is 100 marks. The exact weightings vary slightly, but the third paper is usually synoptic, drawing on the whole course.
What is the difference between WJEC and Eduqas?
WJEC and Eduqas are run by the same awarding body and share almost identical content. WJEC is the qualification used mainly in Wales, with papers available in English and Welsh and a unitised structure of five units. Eduqas is WJEC’s England-facing brand, assessed by three written components and graded on the standard A* to E scale. If you are in Wales you are most likely on WJEC; if you are in England you are most likely on Eduqas.
Should I revise from the specification or a textbook?
Both, but the specification should lead. The textbook explains the content, but the specification tells you exactly what you will be examined on and to what depth. Examiners write questions directly from the specification statements, so the best approach is to use the spec as a checklist and the textbook (and revision resources) to fill in each point. This stops you over-revising content your board does not require and under-revising content it does.
Where can I download my A-Level Biology specification?
Every exam board publishes its current specification free on its website: search for “AQA A-Level Biology specification”, “OCR Biology A specification”, “Edexcel Biology A specification”, “WJEC Biology specification” or “Eduqas Biology specification”. Always check you have the current version and the correct qualification code (for example AQA 7402, OCR H420, Edexcel A 9BN0 or Edexcel B 9BI0), as older or wrong specifications can list different content.