In short
Cambridge IGCSE Combined Science (0653) is one IGCSE covering biology, chemistry and physics. Biology (0610) is a full IGCSE in biology alone. Every 0653 biology objective is also in 0610, but 0653 leaves out five whole topics, including inheritance and coordination. Both have three papers worth 30%, 50% and 20%, with Core and Extended routes.
The short answer: Cambridge IGCSE Combined Science (0653) is a single IGCSE that covers biology, chemistry and physics, and you get one grade from A* to G. Cambridge IGCSE Biology (0610) is a whole IGCSE in biology alone. Every biology learning objective in 0653 is also in 0610, so 0653 biology is a smaller part of the same course. 0653 leaves out five complete 0610 topics (excretion, coordination and response, inheritance, variation and selection, and biotechnology) plus parts of most of the others.
This guide compares the two using the official Cambridge syllabuses: the 0653 syllabus for 2025 to 2027 and the 0610 syllabus for 2026 to 2028. We have free notes, exam questions and flashcards for both: Cambridge IGCSE Combined Science (0653) and Cambridge IGCSE Biology (0610).
0653 vs 0610 at a glance
| Combined Science 0653 | Biology 0610 | |
|---|---|---|
| What it covers | Biology (B1 to B16), Chemistry (C1 to C12) and Physics (P1 to P5). You must study all three | Biology only: 21 topics plus experimental skills |
| Number of IGCSEs | One (a single grade) | One (a single grade) |
| Grades | A* to G (Core route: C to G) | A* to G (Core route: C to G) |
| Papers | Multiple choice 30%, Theory 50%, Practical 20% | Multiple choice 30%, Theory 50%, Practical 20% |
| What each paper tests | All three sciences in every paper | Biology only |
| Biology learning objectives (our count) | 122 (83 Core, 39 Supplement) | 389 |
| Guided learning hours | About 130 (for all three sciences) | About 130 (for biology) |
| Exam series | June and November (also March in India) | June and November (also March in India) |
Is 0653 one or two IGCSEs?
One. 0653 is a single award: you receive one grade on the A* to G scale, the same as for 0610. Cambridge designs both to need "about 130 guided learning hours". The difference is that 0653 fits biology, chemistry and physics into that one IGCSE, while 0610 spends all of it on biology.
The two-grade science course is a different syllabus: Cambridge IGCSE Co-ordinated Sciences (Double Award), 0654. People often mix the two up, so it is worth checking the code on your entry.
0653 vs 0654: single award or double award
| Combined Science 0653 | Co-ordinated Sciences 0654 | |
|---|---|---|
| Award | Single award: one grade, A* to G | Double award: two grades together, A*A* to GG |
| Guided learning hours | About 130 | About 260 |
| Biology topics | B1 to B16 | B1 to B19 (adds Coordination and response, Inheritance, Variation and selection) |
| Theory paper | 1 hour 15 minutes, 80 marks | 2 hours, 120 marks |
| Practical paper | Paper 5: 1 hour 15 minutes, 40 marks. Paper 6: 1 hour, 40 marks | Paper 5: 2 hours, 60 marks. Paper 6: 1 hour 30 minutes, 60 marks |
Both use the same weightings (30% multiple choice, 50% theory, 20% practical) and both have a 45-minute, 40-question multiple-choice paper. Our site covers the biology part of 0653, not 0654.
Which biology topics does 0653 cover?
The 0653 syllabus lists 16 biology topics. Each one matches a 0610 topic, and the wording of most learning objectives is the same as in 0610. The table below goes through all 21 topics of 0610 and shows what 0653 keeps. We built it by comparing every 0653 biology objective with the 0610 syllabus.
| 0610 topic | 0653 topic | Main 0610 content that 0653 leaves out |
|---|---|---|
| 1 Characteristics and classification | B1 (characteristics only) | Classification, binomial names, dichotomous keys, kingdoms and groups (viruses move to B10) |
| 2 Organisation of the organism | B2 Cells | Little: specialised cells are limited to root hair, palisade mesophyll and red blood cells |
| 3 Movement into and out of cells | B3 | Little: for example water as a solvent and protein carriers in active transport |
| 4 Biological molecules | B4 | Structure of DNA |
| 5 Enzymes | B5 | Little |
| 6 Plant nutrition | B6 | Uses of glucose, nitrate and magnesium ions, limiting factors |
| 7 Human nutrition | B7 | Vitamins, minerals and deficiency diseases, teeth, absorption and villi |
| 8 Transport in plants | B8 | Translocation, transpiration pull and wilting |
| 9 Transport in animals | B9 | Single and double circulation, the main blood vessels, lymphocytes and phagocytes |
| 10 Diseases and immunity | B10 | Cholera, antigens and memory cells, vaccination in detail, passive immunity |
| 11 Gas exchange in humans | B11 | Ventilation, inspired and expired air, protecting the breathing system |
| 12 Respiration | B12 (aerobic only) | Anaerobic respiration and oxygen debt |
| 13 Excretion in humans | Not in 0653 | The whole topic |
| 14 Coordination and response | Not in 0653 | The whole topic: nerves, the eye, hormones, homeostasis, tropisms |
| 15 Drugs | B13 | Little |
| 16 Reproduction | B14 | Asexual reproduction, self- and cross-pollination, pregnancy and the placenta, sex hormones, STIs |
| 17 Inheritance | Not in 0653 | The whole topic: genes, mitosis and meiosis, genetic crosses |
| 18 Variation and selection | Not in 0653 | The whole topic: variation, adaptive features, natural selection and selective breeding |
| 19 Organisms and their environment | B15 | Trophic levels and pyramids, the nitrogen cycle, population growth curves |
| 20 Human influences on ecosystems | B16 | Food production, pollution, greenhouse gases, sustainable resources |
| 21 Biotechnology and genetic modification | Not in 0653 | The whole topic |
So 0653 is not easier biology. It is less biology. Where a topic is kept, the questions can be just as demanding, for example explaining enzyme action with the active site, or how temperature and pH affect enzymes. The topics with the most 0653 content are movement into and out of cells, plant nutrition, transport in animals, reproduction and human influences on ecosystems.
Revising 0610 material you will never be asked. If you take 0653, use the 0653 revision notes, which show only the biology in your syllabus, and tick off points on the 0653 specification checklist.
Core and Supplement: the same idea, different labels
Both syllabuses use the same two-column layout. The left column is Core and the right column is Supplement. Core candidates sit Papers 1 and 3 and can get grades C to G. Extended candidates are taught Core plus Supplement, sit Papers 2 and 4, and can get A* to G. Cambridge says candidates expected to get a grade D or below should be entered for Core.
The catch is that the same point can sit in a different column. By our count, 22 biology objectives that are Core in 0610 are Supplement in 0653. They include active transport, the functions of amylase, protease and lipase and where they are made, the functions of stomach acid, coronary heart disease and its risk factors, investigating factors that affect diffusion and transpiration, the role of blood clotting, and how endangered species can be conserved. Deforestation is split: 0653 Core only asks you to state its effects, and explain is Supplement. Nothing works the other way round: no Supplement point in 0610 is Core in 0653.
On our 0653 pages, these points are labelled Supplement, so a Core candidate can see what to skip. For example, how enzymes work (the active site) is Supplement in 0653.
Papers, marks and weighting
The papers have exactly the same shape in both syllabuses. Everyone takes three papers.
| Paper | Route | Time | Marks | Weighting |
|---|---|---|---|---|
| Paper 1: Multiple Choice (Core) | Core | 45 minutes | 40 | 30% |
| Paper 2: Multiple Choice (Extended) | Extended | 45 minutes | 40 | 30% |
| Paper 3: Theory (Core) | Core | 1 hour 15 minutes | 80 | 50% |
| Paper 4: Theory (Extended) | Extended | 1 hour 15 minutes | 80 | 50% |
| Paper 5: Practical Test | Both | 1 hour 15 minutes | 40 | 20% |
| Paper 6: Alternative to Practical | Both | 1 hour | 40 | 20% |
The big difference is what is on each paper. A 0610 theory paper is 80 marks of biology. A 0653 theory paper is 80 marks shared between biology, chemistry and physics. The syllabus does not set a fixed share for each science, so expect each one to appear on every paper. The assessment objectives are weighted the same in both: 50% knowledge with understanding, 30% handling information and problem-solving, and 20% experimental skills. For how the theory answers are credited, see how IGCSE Biology is marked.
Practical papers: what changes in 0653
Your school chooses Paper 5 (a lab test) or Paper 6 (a written alternative to practical), and both test the same skills. Neither syllabus has a list of required practicals. Instead, each lists experimental contexts. The 0653 biology list is the same as the 0610 list except that it drops three contexts: tropic responses, continuous and discontinuous variation and sampling methods. So the 0610 practicals on tropisms in seedlings and continuous and discontinuous variation are not needed for 0653.
0653 adds some skills shared with chemistry and physics, such as correcting for zero errors, identifying random and systematic errors, and judging whether results are equal within about ±10%. It also lists DCPIP and Visking (dialysis) tubing as apparatus for the practical papers, even though they are not in its learning objectives. Our 0653 practicals and experimental skills notes cover the biology side, and our guide to IGCSE Biology Paper 6 explains the question types.
A 0653 practical paper tests skills from all three sciences, but the core habits are the same: control variables, record results in a table with units in the headings, plot clear graphs and suggest specific improvements.
Which should you take?
In most schools the school decides, often by setting students into Combined or separate sciences. If you have a choice, these points come from the syllabuses themselves:
- You want to study biology further. 0610 states that candidates with A* to C are "well prepared to follow a wide range of courses including Cambridge International AS & A Level Biology". 0653 says A* to C candidates are well prepared for "a wide range of Cambridge International AS & A Level courses", without naming biology. 0653 also leaves out inheritance, coordination and response and biotechnology, which A-level courses build on.
- You want a broad science background in one IGCSE. 0653 gives you all three sciences in about the same teaching time as one separate science.
- You want three science grades. 0610 is one of three separate sciences (with Chemistry 0620 and Physics 0625). Co-ordinated Sciences 0654 gives two grades.
- Entry rules. Cambridge does not let you take 0653 and 0610 in the same exam series. 0653 also cannot be combined with 0620, 0625 or 0654.
Neither syllabus says how a particular sixth form or university will treat 0653 compared with 0610. Both say Cambridge IGCSEs are accepted by universities, and that UK ENIC found Cambridge IGCSE comparable to the GCSE standard. Entry requirements are set by each institution, so if you plan to take biology at A-level or IB, ask the sixth form directly whether Combined Science meets its requirement.
Moving between 0653 and 0610
From 0653 to 0610: everything you have learned in 0653 biology counts, because it is all in 0610. You need to add the five missing topics: excretion in humans, coordination and response, inheritance, variation and selection and biotechnology and genetic modification. Then fill the gaps inside topics you know, such as anaerobic respiration, villi, ventilation and the nitrogen cycle. Remember that the 22 Supplement points listed above are Core in 0610.
From 0610 to 0653: your biology is already covered, so you can drop the extra topics and focus on chemistry and physics. Check the Core and Supplement labels again, because some points you learned as Core are Supplement in 0653.
Either way, the 0610 specification checklist and the 0653 specification checklist are the quickest way to find gaps. Then practise with the 0653 exam questions or 0610 exam questions, and the official papers linked from our 0653 past papers and 0610 past papers pages. If you are also weighing up boards, read Cambridge vs Edexcel IGCSE Biology.
If you want help moving between the two courses or with either one, we offer 1-to-1 biology tutoring online and in Dubai.
Sources: Cambridge IGCSE Combined Science 0653 syllabus 2025 to 2027, Cambridge IGCSE Combined Science 0653 syllabus 2028 and 2029 (same biology content), Cambridge IGCSE Biology 0610 syllabus 2026 to 2028 and Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 syllabus 2025 to 2027.