How to answer "Define" questions

Define means: Give the precise meaning of a term.

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

AO1. · Also phrased as: state the meaning of, what is meant by

What the examiner is looking for

  • A concise, accurate definition using the exact wording examiners credit.
  • Learn the mark-scheme phrasing — near-misses often lose the mark.

How to structure your answer

  1. One or two precise sentences — no example needed unless asked.

Worked example

Q: Define diffusion. (1 mark)

Model answer: Diffusion is the net movement of particles from a region of higher concentration to a region of lower concentration, down a concentration gradient [1].

Common mistakes

  • Vague wording ("it spreads out") that misses the key terms.
  • Omitting "net movement" or "down a concentration gradient".

Practise it

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