Home›Guides›A Level biology
A Level biology explained
Five specifications, three boards, one A Level. This page walks through what's on each paper, what's allowed in the exam, how the marks are split, and the specification codes if you need to check anything with the school.
One of these qualifications is being withdrawn
- OCR B — Biology B (Advancing Biology) (H422) — OCR is withdrawing this qualification. The final first teach date was September 2026 and the final assessment opportunity is summer 2028. There is no resit opportunity
If your child is taking it, this matters: there is no resit after the final series. A student who misses or fails the exam cannot retake the same qualification.
The other 4 specifications on this page continue as normal. If you are unsure which one your child is entered for, the school office will tell you.
The exam boards compared
There are 5 A Level biology specifications in England. The boards do not teach different biology, what changes is how the course is organised. Your child’s school chooses which one to enter, and it may not be the same board it uses for other subjects. If you do not know which one, the school office will tell you.
At a glance
| AQA | Edexcel A — Biology A (Salters-Nuffield) | Edexcel B — Biology B | |
|---|---|---|---|
| Specification code | 7402 | 9BN0 | 9BI0 |
| Papers | 3 | 3 | 3 |
| Length of each | 2 hr / 2 hr / 2 hr | 2 hr / 2 hr / 2 hr | 1 hr 45 min / 1 hr 45 min / 2 hr 30 min |
| Marks per paper | 91 / 91 / 78 | 100 / 100 / 100 | 90 / 90 / 120 |
| Total marks | 260 | 300 | 300 |
| Weighting | 35% / 35% / 30% | 33.33% / 33.33% / 33.33% | 30% / 30% / 40% |
| OCR A — Biology A | OCR B — Biology B (Advancing Biology) | |
|---|---|---|
| Specification code | H420 | H422 |
| Papers | 3 | 3 |
| Length of each | 2 hr 15 min / 2 hr 15 min / 1 hr 30 min | 2 hr 15 min / 2 hr 15 min / 1 hr 30 min |
| Marks per paper | 100 / 100 / 70 | 110 / 100 / 60 |
| Total marks | 270 | 270 |
| Weighting | 37% / 37% / 26% | 41% / 37% / 22% |
What is on each paper
| AQA | Edexcel A — Biology A (Salters-Nuffield) | Edexcel B — Biology B | |
|---|---|---|---|
| Paper 1 | Topics 1 to 4 | The Natural Environment and Species Survival | Advanced Biochemistry, Microbiology and Genetics |
| Paper 2 | Topics 5 to 8 | Energy, Exercise and Co-ordination | Advanced Physiology, Evolution and Ecology |
| Paper 3 | Topics 1 to 8, plus the essay | General and Practical Applications in Biology | General and Practical Principles in Biology |
| OCR A — Biology A | OCR B — Biology B (Advancing Biology) | |
|---|---|---|
| Paper 1 | Biological processes | Fundamentals of biology |
| Paper 2 | Biological diversity | Scientific literacy in biology |
| Paper 3 | Unified biology | Practical skills in biology |
AQA does not give its papers names. What each paper covers is shown instead.
In the exam
| AQA | Edexcel A — Biology A (Salters-Nuffield) | Edexcel B — Biology B | |
|---|---|---|---|
| Data or formulae sheet | Not stated in the specification | Not stated in the specification | Not stated in the specification |
| Required practicals | 12 | 18 | 16 |
| Practical endorsement | Separate, does not affect the grade | Separate, does not affect the grade | Separate, does not affect the grade |
| OCR A — Biology A | OCR B — Biology B (Advancing Biology) | |
|---|---|---|
| Data or formulae sheet | Not stated in the specification | Not stated in the specification |
| Required practicals | 12 | 12 |
| Practical endorsement | Separate, does not affect the grade | Separate, does not affect the grade |
Every board sets a number of compulsory practicals, but they do not count them the same way, so the figures are not directly comparable: AQA lists required practicals, Edexcel core practicals, and OCR groups its into Practical Activity Groups. The practical endorsement is reported separately and does not contribute to the A level grade, but a student must complete it to be awarded the qualification.
How the marks are awarded
Whichever board your child sits, the exam rewards the same kinds of thinking in almost the same proportions. About a third of the marks are for straightforward recall (knowing the facts). A little over 40% are for applying that knowledge to a new question. The remaining quarter or so is for analysing, interpreting and evaluating (the harder skills).
Every board also sets a minimum for mathematical content: 10% of the marks in A Level biology are for maths at GCSE higher tier standard or above.
Codes, if you need to check with the school
| AQA | Edexcel A — Biology A (Salters-Nuffield) | Edexcel B — Biology B | |
|---|---|---|---|
| Specification code | 7402 | 9BN0 | 9BI0 |
| Ofqual number | 601/4625/4 | 601/5299/0 | 601/5301/5 |
| Checked against | version 1.6, July 2026 | Issue 4, November 2018 | Issue 4, November 2018 |
| OCR A — Biology A | OCR B — Biology B (Advancing Biology) | |
|---|---|---|
| Specification code | H420 | H422 |
| Ofqual number | 601/4260/1 | 601/4720/9 |
| Checked against | version 4.1, April 2026 | version 3.2, April 2026 |
Every figure above was read from the board’s own specification on the date shown. Specifications change; if you are making a decision on one of these, confirm it with the school.