GCSE Biology Revision: The Topics and Command Words That Decide Your Grade
A practical GCSE Biology revision guide — cell biology to ecology — covering the high-mark topics, required practicals, and how to answer 6-mark questions.
The shape of the course
Paper 1 covers cell biology, organisation, infection and response, and bioenergetics. Paper 2 covers homeostasis, inheritance, variation and evolution, and ecology. Biology has the most content of the three sciences, so triage matters: master the topics that anchor everything else first.
- Cell biology — cell structure, microscopy, transport (diffusion, osmosis, active transport)
- Bioenergetics — photosynthesis and respiration equations, limiting factors
- Homeostasis — blood glucose control, the nervous system, hormones
- Inheritance — Punnett squares, dominant/recessive, genetic diagrams
Command words decide your marks
Most lost marks in Biology aren't knowledge gaps — they're answers that don't match the command word. 'Describe' means say what the data shows. 'Explain' means give the reason why, usually with a mechanism. 'Compare' needs both similarities and differences, with linking words like 'whereas'.
Six-mark questions
Every paper has extended-response questions. Plan for 30 seconds before writing: list the steps of the process in order (e.g. reflex arc: stimulus → receptor → sensory neurone → relay neurone → motor neurone → effector → response). Marks come from complete, ordered chains of logic, not length.
Revision that sticks
Biology is vocabulary-heavy — active recall beats re-reading by a wide margin. Test yourself with exam-style questions, read the explanation for every answer, and keep returning to questions you failed until they stop failing you.
Practise with real exam-style questions
Reading only gets you so far — the fastest way to pass is answering questions under exam conditions. The Revise Right app has 3,800 GCSE Biology questions with full teaching explanations, free on iOS and Android.