CCEA Biology command words: what each one is really asking
Most dropped marks in CCEA Biology are not knowledge failures. They are answers that describe when the question said explain, or list when the question said compare. Command words tell you the shape of the answer the mark scheme is expecting.
The core command words
| Command word | What the mark scheme wants |
|---|---|
| State / Give / Name | A short factual answer. No explanation — and no marks for adding one. |
| Describe | What happens, in order. For data, quote figures with units. |
| Explain | The reason or mechanism. Every 'because' is a separate marking point. |
| Compare | Linked statements about both things in one sentence, not two lists. |
| Suggest | Apply what you know to an unfamiliar context; several answers can be valid. |
| Calculate | Show working. Give the unit and an appropriate number of significant figures. |
| Discuss / Evaluate | Weigh both sides and reach a judgement. Usually carries QWC credit. |
Describe vs explain, using one graph
Imagine a graph of enzyme activity against temperature, peaking at 40 °C.
Describe: activity increases from 0 to 40 °C, reaching a maximum of 12 cm³ min⁻¹ at 40 °C, then falls sharply to zero by 60 °C. Figures quoted, no reasons given.
Explain: as temperature rises, substrate and enzyme molecules gain kinetic energy so there are more successful collisions with the active site per second. Above the optimum, hydrogen bonds holding the tertiary structure break, so the active site changes shape, the substrate no longer fits and the enzyme is denatured.
A student who writes the second answer for a 'describe' question wastes time. A student who writes the first for an 'explain' question loses every mark.
Compare: the single most-wasted command word
'Compare arteries and veins' is not answered by a paragraph about arteries followed by a paragraph about veins. Each marking point needs both halves in the same statement.
Weak: Arteries have thick muscular walls. Veins have valves.
Strong: Arteries have a thicker muscular wall than veins, because they carry blood at higher pressure; veins have valves whereas arteries do not, because the low pressure in veins would otherwise allow backflow.
Suggest means you are not expected to have learnt it
'Suggest' signals an unfamiliar context — an organism or an experiment you have not met. That is deliberate, and it is a good sign: the examiner has given you everything you need in the stem. Read the data, name the biological principle it resembles, and apply it explicitly.
Students lose marks here by hunting for a remembered fact instead of reasoning from what is on the page.
A 10-second check before you write
- Underline the command word and the number of marks.
- Decide the shape: facts, sequence, mechanism, linked comparison, or judgement.
- Count your intended points against the marks available.
Common questions
- Do CCEA and AQA use command words the same way?
- The definitions are broadly similar across boards, but the mark schemes differ in how strictly points are split. Always practise against your own board's papers.