Writing the 25-mark synoptic essay in A Level Biology can feel daunting, but with the right approach you can turn it into a chance to showcase knowledge, links between topics, and exam technique that secures top marks.

What is the synoptic essay in A Level Biology?

The synoptic essay appears in Paper 3 of AQA A Level Biology (7402) and is worth 25 marks.

It requires you to write a structured essay that draws on knowledge from across the two years of the course.

You are given a choice of two titles, usually broad themes such as “The importance of cycles in biology” or “The importance of proteins in living organisms.”

See AQA past essay questions and mark schemes.

What examiners look for

Examiners reward breadth, relevance, and scientific accuracy.

A high-scoring essay includes examples from different topics across the course, not just one unit.

Links between concepts—for example, connecting enzymes, respiration, and ecosystems—are particularly valued.

Clear organisation and use of key terminology are also essential for top-level marks.

How to plan your essay

• Spend at least 5–10 minutes planning before writing.
• Brainstorm as many relevant points from different topics as possible.
• Group ideas into 3–5 main themes that give your essay structure.
• Decide the order you will present them, ensuring logical flow.

How to structure your essay

Start with an introduction that defines key terms and outlines your themes.

Each paragraph should begin with a clear point, followed by explanation, biological detail, and examples.

Link paragraphs together with connecting phrases such as “Similarly,” “In contrast,” or “Another example.”

Finish with a conclusion that summarises your main points and emphasises the significance of the theme to biology.

Tips for gaining higher marks

• Cover a wide range of topics to show breadth of knowledge.
• Always link examples back to the essay title to maintain relevance.
• Use specific scientific terms such as “phosphorylation,” “genetic drift,” or “osmotic potential.”
• Include both molecular-level and ecosystem-level examples where possible.
• Practise writing under timed conditions to build confidence and speed.

Frequently Asked Questions

How many marks is the essay worth?

It is worth 25 marks, which is a significant proportion of Paper 3 in AQA A Level Biology.

Do all exam boards have the essay?

No. The 25-mark essay is specific to AQA Biology (7402). Other boards, like OCR and Edexcel, assess synoptic knowledge in different ways.

How long should I spend on the essay?

Examiners suggest around 35–40 minutes. Plan briefly at the start and leave a few minutes to check your work at the end.

Can I use diagrams?

Yes. Diagrams are allowed and can support your points, but they must be labelled and explained in writing to earn credit.

Ready to practise essay writing?