Understanding Command Words in A-Level Biology Exams
The command word tells you exactly what the examiner wants. Get it wrong and you lose marks even when your biology knowledge is correct. Here is every command word you will encounter, with real Biology examples showing the difference between a losing and a gaining answer.
Why Command Words Matter
A command word is the instruction that tells you what to do with your biological knowledge. It is the difference between a question that wants facts and a question that wants reasoning, between one that wants a simple answer and one that wants balanced evaluation.
Here is why this matters so much: describing when asked to explain earns zero additional marks. You can write a perfectly accurate biological description, but if the question said “explain,” you have not answered the question and the examiner cannot award the marks for reasoning.
After marking thousands of scripts, I can tell you that command word errors account for more lost marks than content gaps. Students who know the biology but misread the instruction consistently score lower than students who may know slightly less but answer the question asked.
High-Frequency Command Words
These appear on every paper. Master these and you will handle the majority of questions correctly.
Describe is about what, not why. If you are describing data, quote specific values with units. If you are describing a process, state the steps in order. Do not explain the reasons behind what happens.
Explain requires cause and effect. Use linking words: “because,” “therefore,” “this means that,” “resulting in,” “due to.” Every statement should connect to a reason. If your answer does not contain at least one “because” or equivalent, you have probably described rather than explained.
The most common mistake with compare is writing about each thing separately. Your statements must be directly linked using words like “whereas,” “while,” “both,” “however,” and “unlike.” If a question says compare, you need both similarities and differences unless it specifies otherwise.
Suggest questions deliberately use contexts you have not studied. The examiner is testing whether you can transfer your understanding. The answer will not be in your notes — you need to work it out using biological principles. The mark scheme is usually broader for suggest questions, accepting multiple valid answers.
Evaluate requires three things: advantages/strengths, disadvantages/limitations, and a conclusion. Simply listing pros and cons without a final judgement is not evaluation. Your conclusion must be supported by the evidence you have presented.
Losing Marks on Exam Technique?
In my sessions, we work through past paper questions together and I show you exactly where command word errors are costing you marks — and how to fix them.
Book Free ConsultationMedium-Frequency Command Words
Outline sits between “state” and “describe.” You need more than a one-word answer, but less detail than a full description. For processes, give the main stages without explaining the mechanism of each stage. Think of it as a summary.
Always show your working. Even if you get the final answer wrong, you can earn method marks for correct working. Include the correct units. Round to an appropriate number of significant figures or decimal places — if in doubt, match the data given in the question.
If a question says “Use the data,” you must quote specific numbers from the graph or table. Writing “the rate increased” without values earns no marks. Write “the rate increased from 12 to 38 cm³ min−¹ between 20°C and 40°C.” Include values, units, and the conditions they correspond to.
Justify is similar to explain, but you are specifically supporting a given conclusion rather than explaining a process. Use evidence from the data or your biological knowledge to show why the conclusion is valid. Common in practical and data analysis questions.
Deduce means the answer is not stated directly — you need to work it out from the information given. Common in genetics questions where you must deduce a genotype from a phenotype ratio, or in data analysis where you must draw a conclusion from experimental results.
Quick-Reference Command Words
These command words require shorter, more direct answers.
- State / Give / Name — A brief factual answer. Often one word, term, or short phrase. No explanation or reasoning required.
- Identify — Recognise and name a specific thing from information provided (e.g., identify the independent variable).
- Label / Annotate — Add names (label) or descriptive notes (annotate) to a diagram.
- Sketch — Draw a simple, clear diagram or graph showing the general shape/relationship. Exact values are not needed, but the shape and key features must be correct.
- Predict — State what you expect to happen based on biological principles. Must be logical and based on your knowledge.
- Design — Plan an experiment or investigation. Must include independent variable, dependent variable, controlled variables, method of data collection, and usually how to ensure reliability.
- Discuss — Present different aspects, arguments, or perspectives on a topic. Similar to evaluate but does not always require a firm conclusion.
The 10-Second Command Word Strategy
Before writing any answer, spend 10 seconds on this:
- Circle the command word in the question.
- Identify what it requires — facts only? Facts + reasons? Both sides + conclusion?
- Check the mark allocation — a 1-mark explain needs one reason; a 6-mark explain needs a structured, multi-point response.
- Plan your answer to match. For 3+ marks, jot down the key terms before writing.
This takes 10 seconds and prevents the most common exam technique error in A-Level Biology. Practise this with every past paper question until it becomes automatic.
Frequently Asked Questions
Describe = state what happens (facts, observations, trends). Explain = state what happens AND give the biological reason why. Use linking words like “because,” “therefore,” “this means.” Describing when asked to explain is one of the most common reasons students lose marks.
Suggest means apply your biological knowledge to an unfamiliar situation. The answer will not be in your notes — you need to use biological principles to work out a reasonable answer. The mark scheme tends to be broader, accepting multiple valid responses.
Use direct linked statements with “whereas,” “while,” “both,” and “however.” Do not write about each thing separately. Include both similarities and differences. Each comparison should be in the same sentence or directly linked.
Weigh up advantages and disadvantages, then reach a supported conclusion. Simply listing pros and cons without a final judgement is not evaluation. Your conclusion must be supported by the evidence you presented.
State = brief factual answer, often one word or phrase. Outline = give essential points or steps without full detail. Outline requires more than state but less than describe. Think of outline as a summary of the key stages.
The command word sets the type of answer; the mark allocation confirms the depth. State/name = minimal (1 mark). Describe = factual detail. Explain = facts + reasoning. Suggest = application. Evaluate = balanced argument + conclusion. Always check how many marks are available and aim for one clear point per mark.