GCSE Biology Topics: Complete List by Board
GCSE Biology topics cover everything from cell structure and genetics to ecosystems and evolution. Whether your child is studying AQA, Edexcel or OCR, Biology is one of three compulsory science subjects, and knowing exactly what is on the exam is the first step toward effective revision.
This guide lists every topic for every major exam board, organised by paper, with clear markers for content that only appears in the Triple (Separate) Science specification. Use it as a revision checklist: print it out, tick off what has been covered, and focus revision time on the gaps.
Combined vs Triple Science: A Quick Recap
Before diving into the topic lists, it is worth understanding the two routes through GCSE Science. Approximately 70% of students take Combined Science (also called Double Science), which covers Biology, Chemistry and Physics in reduced depth and awards two GCSE grades. The remaining 25–30% take Triple Science (Separate Sciences), which gives a standalone GCSE in each science with more content.
The topics listed below cover the full Separate Biology specification. If your child is on Combined Science, they cover the same themes but fewer sub-topics. Items marked “Triple only” are not in Combined Science.
Biology is often considered the most approachable of the three sciences. It is content-heavy, lots of facts, diagrams and processes to learn, but less mathematical than Chemistry or Physics. Approximately 10% of Biology marks involve mathematical skills, compared to ~20% in Chemistry and ~40% in Physics. The trade-off is volume: there is simply more to memorise. For the full difficulty comparison, see our Is GCSE Science Hard? guide.
AQA Biology (8461), 7 Topics Across 2 Papers
AQA is the most popular exam board in England, used by approximately 55% of schools. The AQA biology topics are split across two papers, each lasting 1 hour 45 minutes and worth 100 marks. The specification code is 8461 for Separate Biology and 8464 for Combined Science Trilogy.
Paper 1: Topics 1–4 (1h 45m, 100 marks)
Paper 1 covers the foundational biology: cells, body systems, disease, and energy processes.
| Sub-topic | Key Content | Notes |
|---|---|---|
| Cell structure | Eukaryotic and prokaryotic cells; animal and plant cell structures (nucleus, cytoplasm, cell membrane, mitochondria, ribosomes, chloroplasts, vacuole, cell wall) | |
| Microscopy | Light microscopes, electron microscopes; magnification = image size ÷ actual size | Calculation questions common |
| Cell specialisation | Nerve cells, muscle cells, sperm cells, root hair cells, xylem, phloem | Know structure–function links |
| Cell division | Mitosis, stages of the cell cycle; growth and repair | |
| Stem cells | Embryonic vs adult stem cells; therapeutic cloning; meristems in plants | Ethical issues often examined |
| Transport in cells | Diffusion, osmosis, active transport | Required practical: osmosis |
AQA Topic 1: Cell Biology
| Sub-topic | Key Content | Notes |
|---|---|---|
| Principles of organisation | Cells → tissues → organs → organ systems → organisms | |
| Digestive system | Enzymes (amylase, protease, lipase), bile, stomach acid, small intestine | Required practical: enzymes |
| Heart and blood vessels | Heart structure, arteries, veins, capillaries | Diagram labelling common |
| Blood | Red blood cells, white blood cells, platelets, plasma | |
| Coronary heart disease | Stents, statins, artificial hearts, heart valves, transplants | |
| Health issues | Risk factors for non-communicable diseases (obesity, smoking, alcohol) | |
| Cancer | Benign vs malignant tumours, risk factors, treatment | |
| Plant organ system | Leaves, roots, stems; transpiration; translocation | Triple only (detail) |
AQA Topic 2: Organisation
| Sub-topic | Key Content | Notes |
|---|---|---|
| Communicable diseases | Pathogens: bacteria, viruses, fungi, protists | |
| Specific diseases | Measles, HIV, TMV, salmonella, gonorrhoea, rose black spot, malaria | Know pathogen type + symptoms |
| Human defence systems | Skin, nose hairs, trachea/bronchi (mucus + cilia), stomach acid | |
| Immune system | White blood cells: phagocytosis, antibodies, antitoxins | |
| Vaccination | Dead/inactive pathogen → memory cells → secondary immune response | |
| Antibiotics and painkillers | Antibiotics kill bacteria NOT viruses; antibiotic resistance (MRSA) | Very commonly examined |
| Drug discovery | Preclinical testing, clinical trials, double-blind trials, placebos | |
| Monoclonal antibodies | Production, uses in pregnancy tests, diagnosis, cancer treatment | Triple only |
| Plant disease | Identification, mineral deficiency, plant defence responses | Triple only |
AQA Topic 3: Infection and Response
| Sub-topic | Key Content | Notes |
|---|---|---|
| Photosynthesis | Word and symbol equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂; light energy, chlorophyll | Required practical |
| Rate of photosynthesis | Limiting factors: light intensity, temperature, CO₂ concentration; inverse square law (HT) | |
| Uses of glucose | Respiration, cellulose, amino acids, lipids, starch storage | |
| Aerobic respiration | Glucose + oxygen → carbon dioxide + water (+ energy) | |
| Anaerobic respiration | Animals: glucose → lactic acid; Plants/yeast: glucose → ethanol + CO₂ | Fermentation |
| Response to exercise | Increased heart rate, breathing rate; oxygen debt | |
| Metabolism | The sum of all chemical reactions in a cell |
AQA Topic 4: Bioenergetics
Paper 2: Topics 5–7 (1h 45m, 100 marks)
Paper 2 covers coordination, genetics and the environment. Many students find these topics conceptually harder, particularly genetics and hormones.
| Sub-topic | Key Content | Notes |
|---|---|---|
| Homeostasis | Maintaining constant internal environment: body temperature, blood glucose, water levels | |
| Nervous system | Stimulus → receptor → coordinator → effector → response; reflex arcs; synapses | Required practical: reaction time |
| The brain | Cerebral cortex, cerebellum, medulla; investigating brain function | Triple only |
| The eye | Structure, focusing, accommodation, long/short sight | Triple only |
| Thermoregulation | Vasodilation, vasoconstriction, sweating, shivering | |
| Endocrine system | Hormonal vs nervous control; pituitary gland (master gland), key glands | |
| Blood glucose control | Insulin, glucagon, pancreas; Type 1 vs Type 2 diabetes | |
| Hormones in reproduction | Puberty, menstrual cycle: FSH, LH, oestrogen, progesterone | Higher Tier detail |
| Contraception | Hormonal and non-hormonal methods | |
| Fertility treatments | IVF, FSH and LH injections | Higher Tier |
| Plant hormones | Auxins, phototropism, gravitropism; commercial uses | Triple only |
AQA Topic 5: Homeostasis and Response
| Sub-topic | Key Content | Notes |
|---|---|---|
| Reproduction | Sexual vs asexual reproduction, advantages and disadvantages | |
| Meiosis | Producing gametes, genetic variation, halving chromosome number | |
| DNA and the genome | Double helix, base pairs (A-T, C-G), genes, chromosomes | |
| Genetic inheritance | Dominant/recessive alleles, homozygous, heterozygous, genotype, phenotype | |
| Punnett squares | Predicting genetic crosses; polydactyly, cystic fibrosis | Very commonly examined |
| Sex determination | XX and XY chromosomes | |
| Variation | Genetic causes, environmental causes, or a combination | |
| Evolution | Darwin's natural selection; evidence from fossils and antibiotic resistance | |
| Selective breeding | Advantages and risks (reduced gene pool) | |
| Genetic engineering | Modifying DNA, GM crops, insulin production, ethical concerns | Higher Tier |
| Cloning | Tissue culture, cuttings, embryo transplants, adult cell cloning (Dolly the sheep) | Triple only |
| Classification | Linnaean system, three-domain system (Carl Woese) | |
| Extinction and speciation | Causes of extinction; how new species form |
AQA Topic 6: Inheritance, Variation and Evolution
| Sub-topic | Key Content | Notes |
|---|---|---|
| Ecosystems | Habitats, populations, communities; abiotic and biotic factors | |
| Adaptations | Structural, behavioural, functional; extremophiles | |
| Food chains and webs | Producers, consumers, predators, prey | |
| Levels of organisation | Individual → population → community → ecosystem | |
| Material cycles | Water cycle, carbon cycle | |
| Decomposition | Role of microorganisms; factors affecting decay | Required practical: decay (Triple) |
| Biodiversity | Importance, threats: habitat loss, pollution, deforestation, global warming | |
| Maintaining biodiversity | Breeding programmes, seed banks, reforestation | |
| Trophic levels | Pyramids of biomass | Higher Tier |
| Food production | Farming techniques, biological control | |
| Sustainable fisheries | Managing fish stocks sustainably | Triple only |
| Biotechnology | Role of biotechnology in food production | Triple only |
AQA Topic 7: Ecology
Edexcel Biology (1BI0), 9 Topics Across 2 Papers
Edexcel organises its Edexcel biology GCSE topics differently from AQA. The specification has 9 topics, and there is one important quirk: Topic 1 (Key Concepts in Biology) can appear on both papers. This means the fundamental concepts, cell structure, enzymes, transport, cell division, are always fair game regardless of which paper your child is sitting.
Topic 1 (Key Concepts in Biology) is examined on both Paper 1 and Paper 2. This is unique to Edexcel. Students must revise Topic 1 for every exam, not just Paper 1. It covers cell structure, microscopy, enzymes, transport in cells, and cell division, foundational content that underpins everything else.
Paper 1: Topics 1–5 (1h 45m, 100 marks)
| Topic | Key Content | Notes |
|---|---|---|
| 1: Key Concepts in Biology | Cell structure, microscopy, enzymes, diffusion, osmosis, active transport, cell division (mitosis and meiosis) | Tested on BOTH papers |
| 2: Cells and Control | Mitosis, growth in plants and animals, stem cells, nervous system, synapses, reflex arcs, the eye (Triple only) | |
| 3: Genetics | DNA structure, protein synthesis (HT), Mendel's work, genetic crosses, Punnett squares, sex determination, genetic disorders | |
| 4: Natural Selection and Genetic Modification | Darwin and Wallace, natural selection, evidence for evolution, selective breeding, genetic engineering, classification, extinction | |
| 5: Health, Disease and the Development of Medicines | Communicable diseases, pathogens, STIs, physical and chemical barriers, immune system, vaccination, antibiotics, drug development, non-communicable diseases, cardiovascular disease, cancer |
Edexcel Topics 1–5 (Paper 1)
Paper 2: Topics 1, 6–9 (1h 45m, 100 marks)
| Topic | Key Content | Notes |
|---|---|---|
| 1: Key Concepts in Biology | Same as above, tested on BOTH papers | Also on Paper 1 |
| 6: Plant Structures and Their Functions | Photosynthesis, factors affecting rate, leaf structure, transpiration, translocation, plant hormones (Triple only) | |
| 7: Animal Coordination, Control and Homeostasis | Hormones, menstrual cycle, contraception, blood glucose, diabetes, thermoregulation, the kidney (Triple only), ADH (Triple only) | |
| 8: Exchange and Transport in Animals | Respiration (aerobic and anaerobic), surface area to volume ratio, gas exchange in lungs, circulatory system, blood components, heart structure | |
| 9: Ecosystems and Material Cycles | Communities, food chains, abiotic and biotic factors, parasitism, mutualism, carbon and water cycles, decomposition, biodiversity, human impact, trophic levels, food security |
Edexcel Topics 6–9 (Paper 2)
Edexcel requires 8 core practicals for Separate Biology and 7 for Combined Science. These cover microscopy, osmosis, enzymes, photosynthesis, reaction time, respiration, field investigations, and microbiology.
OCR Gateway Biology (J247), 6 Topics Across 2 Papers
OCR Gateway has the fewest topics (6) and the lowest total marks (180 vs 200 for AQA and Edexcel). The specification code is J247 for Separate Biology and J250 for Combined Science A.
Paper 1: B1–B3 (1h 45m, 90 marks)
| Topic | Key Content | Notes |
|---|---|---|
| B1: Cell Level Systems | Cell structure, enzymes, respiration, photosynthesis, microscopy, cell division | Combines cell biology with bioenergetics |
| B2: Scaling Up | Principles of organisation, diffusion/osmosis/active transport, circulatory system, plant transport | |
| B3: Organism Level Systems | Coordination and control, nervous system, endocrine system, hormones, menstrual cycle, homeostasis, blood glucose |
OCR Gateway Topics B1–B3 (Paper 1)
Paper 2: B4–B6 (1h 45m, 90 marks)
| Topic | Key Content | Notes |
|---|---|---|
| B4: Community Level Systems | Ecosystems, biodiversity, food webs, recycling materials, human impact | |
| B5: Genes, Inheritance and Selection | DNA, protein synthesis (HT), genetic crosses, sex determination, variation, evolution, natural selection, selective breeding, genetic engineering | |
| B6: Global Challenges | Communicable diseases, human defence, vaccination, antibiotics, non-communicable diseases, plant diseases (Triple only), maintaining biodiversity, food production |
OCR Gateway Topics B4–B6 (Paper 2)
One notable difference: OCR combines topics that AQA separates. For example, OCR's B1 covers both cell biology and bioenergetics (photosynthesis, respiration), which are separate topics in AQA. This means fewer topic headings but the same amount of actual content to learn.
Required Practicals (AQA)
At least 15% of exam marks are based on practical knowledge. Students do not sit a separate practical exam, but questions about experimental method, variables, accuracy, and results interpretation appear throughout both papers. Here are AQA's 10 required practicals for Triple Biology (7 for Combined):
Exam Technique for Biology
Biology exams are not just about knowing the content, how you answer matters. Here are the key exam skills:
Extended Writing (6-Mark Questions)
- •Use Point–Evidence–Explain (PEE) structure
- •Write in full sentences with correct scientific terminology
- •Include at least 3 developed points for full marks
- •Quality of written communication is assessed
Command Words
- •Describe = state what happens (observations, trends)
- •Explain = say WHY something happens (mechanisms, reasons)
- •Evaluate = weigh up pros and cons, then give a conclusion
- •Suggest = apply knowledge to an unfamiliar context
Mathematical skills in Biology (~10% of marks):
Magnification calculations
Magnification = image size ÷ actual size. Rearrange to find any of the three values.
Percentage change
Used in osmosis practicals: (change ÷ original) × 100. Remember negative values for decrease.
Mean and range
Calculate the mean of repeated measurements. State the range to indicate reliability.
Rate calculations
Rate = 1 ÷ time. Used in enzyme and photosynthesis experiments.
Interpret graphs and tables
Describe trends, identify anomalies, and draw conclusions from data presented in unfamiliar contexts.
2025 Results in Context
Understanding where Biology sits in the results landscape helps put revision pressure in perspective.
| Measure | Separate Biology | Combined Science |
|---|---|---|
| Grade 4+ pass rate | 89.4% | 57.6% |
| Grades 7–9 | 43.4% | 9.1% |
| Entries | 183,539 | ~470,000 |
| Trend | Down 6% from 2024 | Up ~1-2% |
GCSE Biology Results : 2025
Triple Science is taken by a self-selected cohort of typically higher-ability students. Schools usually enter their strongest science students for Triple and move the rest to Combined. The pass rate difference reflects who sits the exam, not a difference in exam difficulty. If your child is on Combined Science, do not compare their grade to Triple Science statistics. For more context, see our Combined vs Triple Science guide.
These statistics provide useful context for understanding where your child sits relative to the national picture. There is also a broader trend in science entries worth knowing about.
Triple Science entries fell 6% in 2025, from 194,925 to 183,539 for Biology. Combined Science entries increased by approximately 1–2%. This trend is driven by timetabling pressure and staffing constraints, not by the exam getting harder. Ofqual described 2025 as a year of “stability” in grading standards.
How to Use This List for Revision
A topic list is only useful if you actually use it. Here is how to turn this checklist into a revision plan:
Identify your exam board
Check with your school which specification you are studying. AQA (8461), Edexcel (1BI0), or OCR (J247). Your school may also tell you if you are on Combined or Triple.
Print or copy the topic list
Go through each topic and use a traffic light system: green = confident, amber = needs more work, red = not yet learned. Be honest; this is for you, not for anyone else.
Prioritise red and amber topics
Do not spend revision time re-reading content you already know well. Focus on the gaps. If you are unsure where you stand, try a past paper question on the topic.
Check Combined vs Triple content
If you are on Combined Science, ignore the Triple-only content. Do not waste time revising topics that will not appear on your exam.
Build a timetable around the papers
Know which topics are on Paper 1 and which are on Paper 2. Revise Paper 1 topics first (earlier exam date). See our revision timetable guide for a free template.
Test yourself regularly
Reading notes is passive. Testing yourself, flashcards, past papers, practice questions, is far more effective. Aim for retrieval practice, not just re-reading.
For more detailed revision strategies, see our Revision Techniques That Actually Work guide. For a free printable timetable template, see our GCSE Revision Timetable guide. And if your child finds science particularly challenging, our Is GCSE Science Hard? guide puts the difficulty in context with practical advice.
