Most Tested IGCSE Biology Topics

The Most Commonly Tested Topics in IGCSE Biology

Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.

Key point

High-frequency topics: enzymes, transport in humans, coordination, cell transport, photosynthesis. These appear almost every year. Prioritise them first, then move to medium-frequency topics. Never skip a topic entirely.

Not all topics carry equal weight in IGCSE Biology exams. Analysis of past papers reveals consistent patterns in which topics appear most frequently and carry the most marks. Use this to prioritise your revision: not to skip topics, but to allocate time wisely.

High-frequency topics (appear almost every paper)

Topic 5: Enzymes: lock-and-key, temperature/pH effects, rate graphs
Topic 9: Transport in humans: heart structure, blood vessels, blood components
Topic 14: Coordination and homeostasis: reflex arc, blood glucose regulation
Topic 3: Movement in and out of cells: diffusion, osmosis, active transport
Topic 6: Photosynthesis: limiting factors, leaf adaptations

Medium-frequency topics

Topic 17: Inheritance: genetic crosses, Punnett squares
Topic 7: Human nutrition: digestion, enzymes, villi
Topic 10: Diseases and immunity: immune response, vaccination
Topic 19: Ecology: food webs, energy flow, sampling
Topic 12: Respiration: aerobic vs anaerobic

Lower-frequency topics (but still tested)

Topics like classification (Topic 1), drugs (Topic 15), and biotechnology (Topic 21) appear less frequently but still carry marks when they do. Do not skip them: but allocate proportionally less revision time compared to the high-frequency topics.

How to use this information

Ensure you are strongest in the high-frequency topics. These are the ones most likely to appear, so weaknesses here cost the most marks. Once the high-frequency topics are secure, strengthen medium-frequency topics. Only then polish lower-frequency topics.

Frequently asked questions

Can I predict exactly what will be on the exam?

No. Cambridge designs papers to cover the whole syllabus over time, and any topic can appear in any session. Use frequency data to prioritise, not to gamble.