How to Answer 6-Mark Questions in A-Level Biology (All Boards)
An examiner explains exactly how extended response questions are marked, the mistakes that cost students marks on every paper, and a step-by-step method for planning answers that hit Level 3 every time.
Why 6-Mark Questions Matter So Much
Six-mark extended response questions are where grades are won and lost in A-Level Biology.
They typically account for 15–20% of the total marks on each paper, and they are the questions where the mark gap between students is widest. On short-answer questions, the difference between a B-grade and an A*-grade student might be one or two marks. On a 6-mark extended response, the gap is often four or five marks — on a single question.
Having marked thousands of these questions as an examiner for WJEC/Eduqas and Edexcel, I can tell you that the problem is almost never that students lack the knowledge. Most students who score 2/6 actually know enough biology to score 5/6. The problem is how they communicate that knowledge.
This article is going to show you exactly how these questions are marked, what examiners are looking for, and how to structure your answers to consistently hit the top level.
How 6-Mark Questions Are Actually Marked
This is the single most important thing to understand, and most students have never been taught it.
Unlike short-answer questions where each correct point earns a tick, 6-mark questions use levels-based marking. The examiner reads your entire answer and then decides which level it belongs in. Only then do they decide whether it sits at the top or bottom of that level.
| Level | Marks | What the examiner is looking for |
|---|---|---|
| Level 3 | 5–6 | A clear, logically structured answer with relevant scientific detail and appropriate terminology. The reasoning flows, the content is accurate and detailed, and the answer addresses the specific question asked. Written communication is strong. |
| Level 2 | 3–4 | Some relevant scientific content with partial structure. There may be gaps in the reasoning, some vague language, or the answer may drift from the question. Some appropriate terminology is used but not consistently. |
| Level 1 | 1–2 | Basic, fragmentary response. Some relevant information is present but the answer is poorly structured, lacks scientific detail, and uses imprecise language. May contain significant errors or irrelevant content. |
| 0 | 0 | No relevant scientific content or no response. |
The critical insight here is that structure and communication are part of the mark, not just the science. You could include six correct biological facts but if they are written as a disorganised jumble, the examiner may place you in Level 2. Conversely, five well-structured points with clear reasoning will reach Level 3.
The 60-Second Planning Method
Students who plan their 6-mark answers consistently outscore those who start writing immediately. Here is the method I teach every student I work with.
Circle the command word (5 seconds)
Describe = what happens, in sequence. Explain = why it happens, with mechanisms. Evaluate = weigh up evidence, reach a conclusion. Suggest = apply knowledge to an unfamiliar context. Getting this wrong means you answer a different question to the one asked.
Underline the key topic (5 seconds)
What is the question actually about? Sometimes it is obvious. Sometimes a question about “why a plant wilts in salty soil” is really a question about water potential and osmosis, not about plants.
Write a word bank (30 seconds)
In the margin, jot down 6–8 key scientific terms relevant to the question. These are the words the examiner is looking for in your answer. If the question is about enzyme inhibition, your word bank might include: active site, complementary, competitive, non-competitive, allosteric site, rate of reaction, substrate concentration, Vmax.
Number them in logical order (20 seconds)
Decide the sequence your answer should follow. For a “describe” question, this is usually chronological. For an “explain” question, it is cause-and-effect. For “compare,” alternate between the two things being compared.
This takes about 60 seconds. It feels like wasted time. It is not. Students who plan consistently gain 1–2 extra marks per 6-mark question compared to those who dive straight in. Over a full paper with three or four of these questions, that is the difference between grades.
Worked Example With Examiner Commentary
Let me show you exactly how this works with a real-style question.
1. AP arrives → depolarisation of presynaptic membrane
2. Ca2+ channels open → Ca2+ influx
3. Vesicles fuse with presynaptic membrane → exocytosis
4. ACh diffuses across cleft
5. ACh binds to receptors on postsynaptic → complementary
6. Na+ channels open → depolarisation → new AP
7. ACh broken down by AChE → recycled
“The nerve impulse reaches the synapse and chemicals are released into the gap. The chemicals go across to the other side and start another nerve impulse. Then the chemicals are broken down so the synapse can be used again.”
Examiner commentary: This shows basic understanding but uses no scientific terminology. “Chemicals,” “gap,” “the other side” — none of these are marking terms. The mechanism is vague. This reads like GCSE, not A-Level. Level 1: 2 marks.
“When the action potential arrives at the presynaptic knob, the depolarisation causes voltage-gated calcium ion channels to open. Calcium ions diffuse into the presynaptic knob down their concentration gradient. This causes synaptic vesicles containing acetylcholine to fuse with the presynaptic membrane and release acetylcholine into the synaptic cleft by exocytosis. Acetylcholine diffuses across the synaptic cleft and binds to specific, complementary receptors on the postsynaptic membrane. This causes sodium ion channels in the postsynaptic membrane to open, allowing sodium ions to flow in and depolarise the postsynaptic membrane, generating a new action potential. Acetylcholine is then hydrolysed by acetylcholinesterase in the synaptic cleft. The products — choline and ethanoic acid — are reabsorbed into the presynaptic knob to be resynthesised into acetylcholine.”
Examiner commentary: Logical sequence from arrival of AP through to recycling. Uses precise terminology throughout: “voltage-gated calcium ion channels,” “exocytosis,” “complementary receptors,” “acetylcholinesterase,” “hydrolysed.” The answer flows as a coherent explanation with cause-and-effect linking. Clear Level 3: 6 marks.
Notice the Level 3 answer is not dramatically longer — it is perhaps 50% more words. The difference is precision. Every sentence contains a specific marking term. The sequence is logical. There is no waffle.
The Five Mistakes I See on Every Paper
Having marked thousands of extended response questions, I see the same five errors costing students marks on every single paper.
1. Writing everything you know instead of answering the question
If the question asks you to “describe how mRNA is translated,” do not start by explaining transcription. I see this constantly. Students write everything they know about protein synthesis, hoping some of it will earn marks. It does not work. Irrelevant content pushes you down from Level 3 because the examiner sees that you have not actually answered what was asked.
2. Ignoring the command word
“Describe” and “explain” require fundamentally different answers. “Describe the role of insulin” means state what it does. “Explain the role of insulin” means state what it does and why/how — the mechanism. Getting this wrong means you answer a different question, and examiners cannot give marks for a different question no matter how good your biology is.
3. Using vague language
“The substance moves across” is not A-Level language. Which substance? By what process? Across what membrane? In which direction relative to the concentration gradient? Every vague word is a missed marking point. The examiner is looking for specific terms, and if they are not there, the mark is not awarded.
4. No logical structure
An answer that jumps randomly between points forces the examiner to search for your logic. That is a Level 2 characteristic. A Level 3 answer reads as a flowing, logical sequence where each sentence connects to the next. The plan solves this problem before you start writing.
5. Not enough distinct points
A 6-mark answer needs at least six separate pieces of scientific information. Writing beautifully about three points in great depth will earn you three marks, not six. Breadth matters. Aim for 7–8 distinct scientific points to give yourself a margin.
Want an Examiner to Review Your Answers?
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Book Free ConsultationBoard-Specific Differences
While the core skill — structured scientific writing — is the same across all boards, each exam board marks extended responses slightly differently. Knowing your board’s approach gives you a tactical advantage.
Levels-Based Extended Response
AQA uses classic levels-based marking. The mark scheme lists “indicative content” — scientific points that could appear in a good answer — but these are not a tick-list. The examiner assesses the overall quality holistically. Structure and terminology heavily influence which level you reach. AQA also has the unique 25-mark synoptic essay in Paper 3, which follows the same levels principle on a larger scale.
Levels of Response
OCR also uses levels but places particular emphasis on application to unfamiliar contexts. You may be given data or a scenario you have never seen and asked to construct an extended explanation. The quality of your reasoning — how well you connect biological principles to the new context — is what separates Level 2 from Level 3.
Quality of Extended Response (QER)
WJEC and Eduqas explicitly assess the Quality of Extended Response. This means the quality of your scientific argument — logical flow, coherence, and use of evidence — is formally part of the mark. Having examined for WJEC/Eduqas, I can tell you that students who write “everything they know” are the ones who score lowest on QER questions. Focus and structure are rewarded above volume.
Indicative Content Marking
Edexcel tends to use a blend of levels marking and indicative content where specific biological points are expected. The mark scheme lists the key points, and while it is still assessed holistically, hitting those specific points matters more than on some other boards. The pre-released article questions in Paper 3 require you to apply this structured writing to unfamiliar biological contexts.
For a detailed comparison of all exam boards, including paper structures, grade boundaries, and marking styles, see my AQA vs Edexcel vs OCR comparison guide.
How to Practise Effectively
Reading about 6-mark technique is useful. Practising it is what makes the difference. Here is how to build this skill.
Start with mark schemes, not questions
Before you attempt a 6-mark question, read the mark scheme for a similar past question. Study the indicative content. Notice the terminology used. Notice how the Level 3 descriptor is written. This teaches you what the examiner expects before you try to produce it.
Write one answer per day
You do not need to do entire past papers. One 6-mark question per day, properly planned and written, with mark scheme analysis afterwards, is worth more than rushing through ten. Quality over quantity.
Mark yourself ruthlessly
Compare your answer to the Level descriptors, not just the indicative content. Ask: Is my answer structured? Does it flow logically? Have I used precise terminology? Am I in Level 2 or Level 3? Be honest — the examiner will be.
Keep a mistake log
After each practice answer, write down what you dropped marks for. After two weeks, patterns will emerge. Maybe you consistently forget to address both parts of two-part questions. Maybe your terminology is weak on one topic. The log tells you exactly what to fix.
You can find links to official past papers and mark schemes for all exam boards on my resources page.
The Bottom Line
Six-mark questions are not a mystery. They are a skill — and like any skill, they can be taught, practised, and mastered. The students who score consistently high on these questions are not the ones who know the most biology. They are the ones who communicate biology most precisely, in a logical structure, using examiner-friendly terminology.
If you are consistently scoring 2–3 on extended response questions and want to move to 5–6, the strategies in this article will get you there. If you want expert feedback on your answers from someone who has actually sat on the other side of the mark scheme, I offer one-to-one online tuition and small group sessions covering all major exam boards.
Frequently Asked Questions
Most use levels-based marking rather than point-based. Examiners assess your answer holistically against three levels: Level 1 (1–2 marks) for basic responses, Level 2 (3–4 marks) for answers with understanding but gaps, and Level 3 (5–6 marks) for clear, logically structured answers with relevant scientific detail. The quality of written communication determines whether you sit at the top or bottom of each level.
For levels-based questions, continuous prose is strongly recommended. Part of the assessment is how you construct a logical, flowing argument. Bullet points make it harder for the examiner to assess your reasoning and can limit you to the lower end of a level. Connected sentences show understanding rather than just recall.
Approximately 6–7 minutes including planning. Spend 1–2 minutes planning — identifying key points, ordering them, checking the command word. Then write for 4–5 minutes. Students who plan first almost always outscore those who start immediately.
AQA uses levels-based extended response marking assessed holistically. OCR emphasises application to unfamiliar contexts. WJEC/Eduqas explicitly assesses Quality of Extended Response (QER). Edexcel uses a blend of levels and indicative content marking. The fundamental skill — structured scientific writing — is the same, but the emphasis differs.
The five most common: writing everything you know rather than answering the specific question; ignoring the command word; using vague language instead of precise terminology; failing to structure the answer logically; and not including enough distinct biological points. A 6-mark answer needs at least six separate pieces of scientific information.
Use a 60-second method: circle the command word, underline the key topic, jot down 6–8 key terms in the margin as a word bank, then number them in logical order. This takes a minute but typically gains 1–2 extra marks. If you run out of time, the plan itself can earn marks.