Every year, thousands of GCSE Science students lose marks not because they do not know the science, but because they do not answer the question properly. The key is understanding command words — the instruction words that tell you exactly what the examiner expects.

State / Give / Name (1 mark each)

These are the simplest command words. They require a short, factual answer with no explanation needed. Example: "Name the organelle where photosynthesis occurs." Answer: "Chloroplast." Keep it brief — one word or short phrase is enough.

Describe (2-3 marks)

Describe means "say what happens" or "say what you see." You need to give an account of the main features but you do not need to explain why. Example: "Describe the trend shown in the graph." Answer: "As temperature increases from 20 to 40 degrees, the rate of reaction increases. Above 40 degrees, the rate decreases rapidly."

Explain (2-4 marks)

Explain means "give reasons why." This is where you need to show understanding, not just recall. Use the word "because" to make sure you are giving reasons. Example: "Explain why the rate of photosynthesis increases with light intensity." Answer: "As light intensity increases, more light energy is available for the light-dependent reactions, so more glucose is produced because the rate of the Calvin cycle increases."

Compare (2-3 marks)

Compare means identify both similarities AND differences. Always mention both. Use comparative language: "whereas," "but," "both," "however." Example: "Compare arteries and veins." Answer: "Both carry blood around the body. However, arteries carry blood away from the heart at high pressure and have thick muscular walls, whereas veins carry blood back to the heart at low pressure and have thinner walls with valves."

Evaluate (3-6 marks)

Evaluate means weigh up evidence for and against, then reach a supported conclusion. Structure your answer: advantages, disadvantages, then your judgement. Example: "Evaluate the use of stem cells in medicine." Cover benefits (can treat diseases), limitations (ethical concerns, risk of rejection), and conclude with your supported opinion.

Calculate / Determine (1-3 marks)

These require a mathematical answer. Always show your working — even if your final answer is wrong, you can still get marks for correct method. Write the formula, substitute the values, and give your answer with the correct unit. Circle or underline your final answer.