IGCSE Biology covers cells, plants, human biology, inheritance, ecology and biotechnology. But what you need to revise, and which exam papers you take, depends on your qualification.
This guide covers Cambridge IGCSE Biology 0610 and Pearson Edexcel International GCSE Biology, including the 4BI1 linear and 4XBI1 modular routes. You will find the main topic lists, paper requirements and practical revision tasks to turn the syllabus into a manageable study plan.
The essentials
- Edexcel 4BI1: five broad topics; Paper 1 (2 hours, 61.1%) and Paper 2 (1 hour 15 minutes, 38.9%), and Paper 2 can test everything.
- Cambridge 0610: 21 topics; Core or Extended, plus a Practical Test or Alternative to Practical worth 20%.
- Edexcel modular 4XBI1: two units of 1 hour 40 minutes each, with the content split between them.
- Revise from your own syllabus. Older topic lists can include material that is no longer examined.
Which IGCSE Biology syllabus do you need for 2027?
Before choosing revision notes or past papers, find your qualification code on your course information or statement of entry.
| Qualification | Code | Your assessment route |
|---|---|---|
| Cambridge IGCSE Biology | 0610 | Core or Extended, plus a practical assessment |
| Edexcel International GCSE Biology (linear) | 4BI1 | Paper 1B and Paper 2B |
| Edexcel International GCSE Biology (modular) | 4XBI1 | Biology Unit 1 and Unit 2 |
For Cambridge Biology exams in 2027, use the 2026–2028 syllabus. Its latest version (version 3) was published in August 2026, with no significant changes affecting teaching. The year you sit the exam decides which syllabus you need.
Note
This guide covers separate Biology qualifications. If you take combined or double-award science, follow your own qualification's content requirements.
Edexcel IGCSE Biology topics: the full main-topic list
The Edexcel 4BI1 linear specification organises Biology into five broad topics, each with smaller sections and numbered learning statements. Use this list to organise your revision, then use the numbered statements to check the precise detail required.
1. The nature and variety of living organisms
This topic introduces living organisms and the differences between major biological groups. Revise:
- characteristics shared by living organisms;
- features of plants, animals, fungi and protoctists;
- eukaryotic and prokaryotic organisms;
- characteristics of bacteria and viruses;
- pathogens and examples of the diseases they cause.
Try it
Make a comparison table for the groups of organisms, including cell structures and how they get their nutrients. Complete it without looking at your notes.
2. Structure and functions in living organisms
This is a large topic, so divide it into smaller revision sessions.
| Section | What to revise |
|---|---|
| Organisation | Organelles, cells, tissues, organs and organ systems |
| Cells | Structures, functions, differentiation and stem cells |
| Biological molecules | Carbohydrates, proteins, lipids, food tests and enzymes |
| Movement across membranes | Diffusion, osmosis and active transport |
| Plant nutrition | Photosynthesis, leaf adaptations and limiting factors |
| Human nutrition | Diet, digestion and absorption |
| Respiration | Aerobic and anaerobic respiration |
| Gas exchange | Exchange surfaces in plants and humans |
| Plant transport | Xylem, phloem, transpiration and translocation |
| Human transport | The heart, blood and blood vessels |
| Excretion | Waste removal, kidney function and water balance |
| Coordination and response | Nerves, hormones, the eye and regulation of internal conditions |
Try it
Explain how an alveolus, a villus or a root hair cell is adapted for its function.
Watch out
"It has a large surface area" needs a link to what that surface area achieves, such as faster diffusion of oxygen into the blood.
3. Reproduction and inheritance
This topic explains reproduction and how genetic information passes between generations. Revise:
- sexual and asexual reproduction;
- flowering plant reproduction and seed germination;
- human reproductive systems, hormones, pregnancy and development;
- DNA, genes, chromosomes and protein synthesis;
- genetic terminology and inheritance diagrams;
- mitosis and meiosis;
- variation, mutation, natural selection and antibiotic resistance.
Your turn
Two parents are both heterozygous (Bb) for a characteristic, where B is dominant. What is the probability that a child shows the recessive characteristic? Then explain why a 25% probability does not mean exactly one in four of their children will have it.
AnswerShow answerHide answer
Each parent produces B and b gametes, giving offspring BB, Bb, Bb and bb. Only bb shows the recessive characteristic, so the probability is 1 in 4 (25%). Each fertilisation is an independent random event, so the ratio is an expected proportion; in a small family the actual numbers can easily differ.
4. Ecology and the environment
This topic explores relationships between organisms and their surroundings. Revise:
- habitats, populations, communities and ecosystems;
- sampling using quadrats;
- food chains, food webs and ecological pyramids;
- energy transfer between trophic levels;
- the carbon and nitrogen cycles;
- pollution and eutrophication;
- greenhouse gases and deforestation.
Try it
Explain eutrophication as a chain of causes and effects: nutrient enrichment → algal growth → light blocked → plants die → decomposers multiply → dissolved oxygen falls → fish and other animals die.
5. Use of biological resources
This topic explores how biological knowledge supports food production and other applications. Revise:
- crop production, improving yields and controlling pests;
- yeast in bread-making and bacteria in yoghurt production;
- industrial fermenters;
- fish farming;
- selective breeding;
- genetic modification;
- micropropagation and cloning mammals.
Try it
Compare selective breeding with genetic modification. Explain how each changes the characteristics of organisms before discussing advantages and disadvantages.
Edexcel Biology Paper 1 vs Paper 2: what is assessed?
For Edexcel 4BI1 linear Biology, both papers can assess content from all five main topics.
| Paper | Duration | Marks | Weighting | Content assessed |
|---|---|---|---|---|
| Paper 1B (4BI1/1B) | 2 hours | 110 | 61.1% | Content that is not in bold with a "B" reference |
| Paper 2B (4BI1/2B) | 1 hour 15 minutes | 70 | 38.9% | All content, including bold "B" statements |
Important
Paper 2 is not restricted to the extra Biology content. You also need to revise the content shared with Paper 1.
The "B" references mark extra content for separate Biology beyond Science (Double Award). Edexcel 4BI1 is untiered: its use of "core content" does not mean a Cambridge-style Core entry. Practical skills are assessed within the written exams, and the specification includes required practicals as numbered statements (for example, food tests and the effect of temperature on enzyme activity).
Edexcel modular Biology: which topics are in each unit?
Students taking 4XBI1 modular Biology follow a different structure, set out in the modular specification.
| Unit | Main content | Duration | Marks | Weighting |
|---|---|---|---|---|
| Unit 1 (4WBI1/1B) | Living organisms; organisation; cells; biological molecules; movement across membranes; nutrition; respiration; gas exchange | 1 hour 40 minutes | 90 | 50% |
| Unit 2 (4WBI2/1B) | Transport; excretion; coordination; reproduction; inheritance; ecology; biological resources | 1 hour 40 minutes | 90 | 50% |
Both units assess their relevant bold "B" content, and both are available in June and November.
Watch out
Do not apply the linear Paper 1/Paper 2 split to modular exams. The modular route is only available to schools outside the UK; see Edexcel IGCSE modular vs linear for how units, UMS and cash-in work.
Tip
Label your resources "Unit 1" or "Unit 2" so you can focus on the content for your next assessment.
Cambridge IGCSE Biology 0610 topics for 2027
Cambridge organises Biology into 21 main topics. Core and Extended students use the same topic framework, but Extended students also study the Supplement learning objectives.
| No. | Topic | Main areas to revise |
|---|---|---|
| 1 | Characteristics and classification of living organisms | Life processes, species, naming, classification and dichotomous keys |
| 2 | Organisation of the organism | Cell structures, specialised cells, levels of organisation and magnification |
| 3 | Movement into and out of cells | Diffusion, osmosis and active transport |
| 4 | Biological molecules | Carbohydrates, fats, proteins, food tests and DNA structure |
| 5 | Enzymes | Enzyme action, temperature, pH and denaturation |
| 6 | Plant nutrition | Photosynthesis, leaves, mineral requirements and limiting factors |
| 7 | Human nutrition | Diet, digestion, teeth, digestive enzymes and absorption |
| 8 | Transport in plants | Xylem, phloem, water uptake, transpiration and translocation |
| 9 | Transport in animals | Circulation, heart, blood vessels, blood and coronary heart disease |
| 10 | Diseases and immunity | Pathogens, transmission, body defences, antibodies and vaccination |
| 11 | Gas exchange in humans | Breathing structures, ventilation, gas exchange and exercise |
| 12 | Respiration | Aerobic and anaerobic respiration, energy release and oxygen debt |
| 13 | Excretion in humans | Urinary system, kidneys, nephrons, urea and deamination |
| 14 | Coordination and response | Nervous system, reflexes, synapses, eyes, hormones, homeostasis and tropisms |
| 15 | Drugs | Antibiotics, bacterial resistance and appropriate antibiotic use |
| 16 | Reproduction | Asexual and sexual reproduction, plants, humans, hormones and sexually transmitted infections |
| 17 | Inheritance | Genes, chromosomes, protein synthesis, cell division and genetic crosses |
| 18 | Variation and selection | Variation, mutations, adaptation, natural selection and selective breeding |
| 19 | Organisms and their environment | Energy flow, feeding relationships, nutrient cycles and populations |
| 20 | Human influences on ecosystems | Food supply, habitat destruction, pollution and conservation |
| 21 | Biotechnology and genetic modification | Microorganisms, industrial enzymes, fermenters and gene transfer |
Core vs Extended: what do you need to learn?
| Route | What you study | Grades available |
|---|---|---|
| Core | Core objectives only | C–G |
| Extended | Core and Supplement objectives | A*–G |
Key point
Supplement adds detail within topics. It is not a separate set of chapters you can revise apart from Core.
Important corrections to older Cambridge topic lists
Some older summaries include material beyond the current syllabus. In the 2026–2028 syllabus:
- Drugs (Topic 15) focuses on antibiotics and antibiotic resistance, not alcohol and heroin.
- Excretion (Topic 13) does not name ADH as a requirement.
- Biotechnology (Topic 21) does not prescribe micropropagation or cloning mammals; those belong to the Edexcel specification.
Check
Use the individual learning objectives to judge the depth required. A topic appearing in your textbook does not automatically mean every detail is examinable.
Which Cambridge Biology papers do you take?
You take three papers, depending on your route:
- Core: Paper 1 + Paper 3 + either Paper 5 or Paper 6.
- Extended: Paper 2 + Paper 4 + either Paper 5 or Paper 6.
| Paper | Assessment | Duration | Marks | Weighting |
|---|---|---|---|---|
| 1 | Core multiple choice | 45 minutes | 40 | 30% |
| 2 | Extended multiple choice | 45 minutes | 40 | 30% |
| 3 | Core theory | 1 hour 15 minutes | 80 | 50% |
| 4 | Extended theory | 1 hour 15 minutes | 80 | 50% |
| 5 | Practical Test | 1 hour 15 minutes | 40 | 20% |
| 6 | Alternative to Practical | 1 hour | 40 | 20% |
The multiple-choice and theory papers draw on all the content for your route; Cambridge does not assign one set of chapters to multiple choice and another to theory.
Watch out
Paper 6 is a written test of practical skills. You still need to understand experiments, measurements, graphs and evaluation.
What did the boundaries look like in June 2026?
- Edexcel 4BI1: grade 9 needed 142 out of 180, grade 7 needed 112 and grade 4 needed 67.
- Cambridge 0610 (Extended): A* needed between 165 and 171 out of 200, depending on the paper variant and practical option taken.
See every grade and route on Starley's pages for Cambridge 0610, Edexcel 4BI1 and Edexcel modular Biology. Boundaries change every series, so use them to interpret past-paper practice, not as targets.
Practical skills to revise alongside every topic
When revising an investigation, work through these questions:
- What do I change? Identify the independent variable.
- What do I measure? Identify the dependent variable and its units.
- What do I keep constant? Name specific control variables and how to control them.
- How do I collect useful results? Describe apparatus, measurements and repeats.
- How do I present the data? Choose an appropriate table or graph.
- What conclusion is supported? Refer to the results.
- What could be improved? Identify a limitation and a specific improvement.
Example
In a potato osmosis investigation, think about solution concentration (independent variable), percentage change in mass (dependent variable), initial potato size, immersion time, temperature, and blotting the potato pieces dry before weighing.
Do more than memorise the method: explain why each step matters.
Rather than
"Make the experiment more accurate."
Try
"Blot each potato piece the same way before weighing, so surface water does not add to the mass." State what you would change and how it improves the measurement.
How to turn the Biology topic list into a revision plan
1. Test each topic before rating it
Answer a short question set without notes, then rate the topic:
| Rating | What it means | Next action |
|---|---|---|
| Red | You cannot explain the main ideas | Learn a small section, then test it |
| Amber | You know the content but struggle to apply it | Practise unfamiliar exam questions |
| Green | You can answer and explain accurately | Revisit through mixed questions |
Remember
Recognising a page of notes is not the same as being able to answer a question.
2. Choose a specific learning objective
"Revise human biology" is too broad. A better task is "Explain how alveoli are adapted for gas exchange": you can finish it, test it and see what still needs work.
3. Use a focused revision session
| Time | Task |
|---|---|
| 5 minutes | Recall what you know without notes |
| 10 minutes | Learn or repair one specific gap |
| 15 minutes | Answer relevant exam questions |
| 10 minutes | Mark, explain mistakes and rewrite weak answers |
Return to the same objective a few days later. Can you still explain it without help? Starley's flashcards and practice questions are handy for quick recall checks.
4. Keep an error log
Record the cause of each mistake, not just the correct answer.
| Problem | Useful follow-up |
|---|---|
| Missing knowledge | Create a short recall question |
| Confused concepts | Compare the ideas side by side |
| Incomplete explanation | Link cause, process and outcome |
| Misread data | Practise axes, units, trends and figures |
| Calculation error | Show formula, substitution and units |
| Weak practical answer | Practise variables and specific improvements |
5. Progress to timed papers
Topic questions repair individual weaknesses; full papers test whether you can manage time, switch between topics and interpret unfamiliar information. Starley's past papers are organised by board and code.
After marking a paper, choose three precise revision targets. "Improve Biology" gives you little direction; "Explain the differences between arteries and veins using structure and function" gives you a clear next task. For a broader plan, see how to start revision.
Common mistakes that cost Biology marks
| Mistake | The fix |
|---|---|
| Confusing respiration with breathing | Respiration is chemical reactions in cells that release energy; breathing ventilates the lungs |
| Confusing excretion with egestion | Excretion removes metabolic waste; egestion removes undigested food |
| Naming an adaptation without its function | Connect the feature to the process it supports |
| Describing when asked to explain | Give the biological reason behind the observation |
| Ignoring data | Support your answer with figures and units where relevant |
| Mixing units in magnification calculations | Convert image size and actual size to the same unit first |
| Memorising answers without understanding | Practise applying the idea to a different organism or situation |
Your turn
A cell is 0.05 mm long, and its image in a diagram is 25 mm long. What is the magnification?
AnswerShow answerHide answer
Magnification = image size ÷ actual size = 25 mm ÷ 0.05 mm = ×500. Both measurements are already in millimetres, so no conversion is needed.
Frequently asked questions
Does Cambridge have more Biology content than Edexcel?
You cannot compare workload by counting headings. Cambridge uses 21 sections, while Edexcel linear uses five broad topics. Compare the detailed learning objectives and the depth required for your route. For a wider comparison, see Cambridge vs Edexcel vs OxfordAQA IGCSE.
Can I use another exam board's Biology notes?
They can help explain shared scientific ideas. Use your own specification to decide what to learn and your own board's questions to practise the assessment style, and keep track of material that is missing from, or extra to, your course.
Can I skip a topic because it appeared last year?
No. Do not leave out a topic just because it appeared on a previous paper. If time is short, prioritise your weaknesses while still reviewing the whole syllabus for your route.
What should I revise first if I am behind?
Start with a short diagnostic question set. Repair foundations such as cells, movement across membranes, biological molecules and enzymes where needed, then tackle your weakest areas. Include practical and data questions throughout.
Is learning the topic list enough for a top grade?
The list helps organise your work. Strong exam performance also needs precise explanations, calculations, practical reasoning and applying knowledge to unfamiliar examples. Use exam questions to test those skills rather than relying on rereading.
When are the 2027 IGCSE Biology exams?
Edexcel 4BI1 Paper 1 is on Tuesday 11 May 2027 and Paper 2 on Thursday 10 June 2027. See our IGCSE resit dates 2027 guide for Edexcel and OxfordAQA dates, and Starley's Edexcel International GCSE exam timetable. For Cambridge dates, check with your exam centre.