The Most-Tested Topics in IGCSE Biology (CIE 0610)
Every 0610 past-paper question, tagged to its syllabus topic — ranked by how often each is tested (2020–2025).
Core tier (Papers 1 / 3)
80 papers analysed · top 15 of 60 topics
| # | Topic | % of tier's questions | Questions | Avg marks |
|---|---|---|---|---|
| 1 | Cell structure | 5.8% | 111 | 10.3 |
| 2 | Enzymes | 5.1% | 98 | 10.6 |
| 3 | Biological molecules | 4.5% | 86 | 10.7 |
| 4 | Photosynthesis | 4.1% | 79 | 10.7 |
| 5 | Sexual reproduction in humans | 3.9% | 74 | 9.1 |
| 6 | Diseases and immunity | 3.7% | 71 | 10 |
| 7 | Concept and uses of classification systems | 3.4% | 64 | 9.4 |
| 8 | Gas exchange in humans | 3.2% | 61 | 10.5 |
| 9 | Features of organisms (kingdoms, groups) | 3% | 58 | 9.9 |
| 10 | Monohybrid inheritance | 3% | 57 | 8.7 |
| 11 | Food chains and food webs | 2.8% | 53 | 11.9 |
| 12 | Anaerobic respiration | 2.7% | 52 | 10.1 |
| 13 | Characteristics of living organisms | 2.6% | 49 | 10.4 |
| 14 | Excretion in humans | 2.6% | 49 | 10.6 |
| 15 | Diet | 2.5% | 48 | 10.5 |
Extended tier (Papers 2 / 4)
80 papers analysed · top 15 of 61 topics
| # | Topic | % of tier's questions | Questions | Avg marks |
|---|---|---|---|---|
| 1 | Enzymes | 5.4% | 100 | 12.6 |
| 2 | Diseases and immunity | 5% | 92 | 14.7 |
| 3 | Chromosomes, genes and proteins | 4.7% | 86 | 12.5 |
| 4 | Cell structure | 4.5% | 83 | 12.9 |
| 5 | Monohybrid inheritance | 3.8% | 70 | 13.1 |
| 6 | Features of organisms (kingdoms, groups) | 3.7% | 68 | 13.7 |
| 7 | Photosynthesis | 3.6% | 66 | 14.6 |
| 8 | Gas exchange in humans | 3.6% | 66 | 13.3 |
| 9 | Excretion in humans | 3.1% | 58 | 12.9 |
| 10 | Genetic modification | 3% | 55 | 15.4 |
| 11 | Biological molecules | 3% | 55 | 13.7 |
| 12 | Chemical digestion | 2.9% | 53 | 13.2 |
| 13 | Osmosis | 2.7% | 50 | 12.8 |
| 14 | Nutrient cycles | 2.6% | 47 | 13.2 |
| 15 | Anaerobic respiration | 2.6% | 47 | 12.8 |
How this was measured
Based on OwlsPrep's database of official CIE 0610 past papers (2020–2025), 3927 questions each tagged to its syllabus topic. Topics are grouped by paper tier; “% of tier's questions” = the share of that tier's tagged questions testing the topic. Because one question can test several topics, shares do not sum to 100%. Figures are aggregate statistics from question metadata — no exam questions or mark schemes are reproduced.
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