By Cyril KimbiBiology candidates rarely fail because they do not know the biology. They fail because they write essays where the marking scheme wanted a list of scoring points, or describe a process when the question asked them to explain it. The knowledge is usually there; the marks are lost in transmission.
How a long answer is actually marked
An examiner works down a list. Each item on that list is worth a mark, and they scan your answer for it. They are not forming an overall impression of your essay.
This single fact should change how you write. A beautifully constructed paragraph containing three scoring points earns three marks. Five terse lines containing five scoring points earn five. On a six-mark question, the candidate who writes less structured prose and more distinct points wins.
Practically: one idea per line. It is easier for you to check you have made enough points, and easier for the examiner to find them — and an examiner who cannot find a point does not award it.
Let the marks tell you how much to write
The mark allocation is an instruction about quantity, and it is far more reliable than the size of the space provided.
| Marks | What is expected |
|---|---|
| 1-2 | A term, or a term plus its function |
| 3-4 | Three or four distinct points, briefly |
| 5-6 | Five or six points, often a sequence in order |
| 7+ | A structured account, usually with a named example |
Before writing, glance at the marks and decide how many separate points you owe. It takes three seconds and it prevents the most common failure: writing at length about one point on a question wanting six.
The command words, and what each demands
- State / Name — the term alone. Adding explanation wastes time you need elsewhere.
- Describe — what happens, in sequence. No reasons required.
- Explain — why it happens. This is where most marks in biology are lost.
- Compare — both things in the same sentence. Two separate descriptions is not a comparison.
- Suggest — apply what you know to an unfamiliar case; several answers may be accepted.
- Outline the role of — function, plus what fails without it.
The describe/explain distinction deserves its own attention because it is worth so many marks across a paper. “The stomata close” is a description. “The stomata close, which reduces water loss by transpiration when the plant is losing water faster than it can absorb it” is an explanation. The clause after the comma is the mark.
A reliable habit: whenever you write a biological change, ask so what? and write the answer. That question converts descriptions into explanations mechanically.
Use the exact term
Biology mark schemes frequently require specific vocabulary. Describing around a term you cannot recall usually earns nothing, even when the description is correct.
“The tube that carries water up the plant” does not score where “xylem” does. “When water moves from where there is more to where there is less” does not score where “osmosis” does, and “down a water potential gradient” scores again.
This is worth deliberate revision. Go through each topic and list the terms the syllabus names, then test yourself on the term from the definition rather than the other way round — that is the direction the exam asks for.
Diagrams
Marks in biology diagrams sit in the labels, not the drawing. An unlabelled diagram, however accurate, usually earns nothing.
- Label everything the question could plausibly want.
- Use a ruler and a pencil — label lines must touch the structure without ambiguity.
- Add a title and, for a specimen, a magnification if you have one.
- Draw large. A small diagram cannot be labelled clearly, and unclear labels are not awarded.
Where a question offers the choice, a labelled diagram is often faster than prose and scores the same. Use that when time is short.
Practising this properly
Reading model answers teaches you what a good answer looks like and does not teach you to produce one. The sequence that works:
- Answer the question under time, closed book.
- Mark it yourself against the marking scheme, strictly. If the scheme required a term and you described it, you did not earn the mark.
- Log what you lost. After ten questions you will have a short list — almost always the same three or four failures repeating.
- Work only that list.
Marking yourself generously is the most expensive habit in revision, because it trains you to keep writing answers that do not score. The past papers library supplies the questions and schemes.
In the exam
Read the whole paper first and start with the questions you can definitely do — marks count the same in any order, and early success steadies you. Watch the clock against the marks rather than the questions: a 15-mark question deserves roughly three times the time of a 5-mark one, regardless of which you prefer.
If you cannot start a question, write anything relevant — a definition, a labelled diagram, a term. Partial credit is real, and a blank space is the only guaranteed zero.
Frequently asked questions
Should I write in paragraphs or bullet points?
Clear separate points, one per line, unless the question explicitly asks for continuous prose. Examiners scan for scoring points.
How long should a 6-mark answer be?
About six distinct points. Length matters far less than the number of separate scoring points.
Do I lose marks for extra information?
Usually not directly, but it costs time and can bury the points that do score. A contradiction can cancel a mark.
Why do I lose marks when my answer is right?
Most often because the required term was missing, the command word wanted an explanation rather than a description, or fewer distinct points were made than the allocation demanded.
Are diagrams worth drawing if not asked for?
Yes, where they add clarity — but only labelled. An unlabelled diagram rarely earns anything.
