Edexcel A Level Biology (9BI0) Past Papers 2026

Advanced Biochemistry, Microbiology and Genetics

Duration: 1h 45m

Advanced Physiology, Evolution and Ecology

Duration: 1h 45m

General and Practical Principles in Biology

Duration: 2h 30m

Photosynthesis — light-dependent reactions and Calvin cycle

'A number of candidates did not link their answer to the thylakoid membranes as required, not gaining the marks. Other common errors were to not use the term "absorb" so missing out on mark point 1, referring to reduced NAD and not reduced NADP so missing out on mark point 2.' Calvin cycle questions in 2024 saw candidates 'simply describe' rather than explain its purpose.

Paper 1

Hardy-Weinberg and population genetics

Candidates confuse q with q² and miss the underlying assumptions. 'A few candidates did not know how to carry out the calculation. Candidates should practise all the steps in a Hardy-Weinberg calculation: find q2, find q, find p (from p+q=1), and then find 2pq.'

Paper 2, Paper 3

Immune response — humoral vs cell-mediated, primary vs secondary

'The responses highlighted just how much confusion there is between the two types of immune responses. Some of the more frequently seen misconceptions were that the HIR had two stages and the CMI only one, T helper cells were only involved in the HIR and not the CMI, that macrophages presented the antigen in the HIR and infected host cells in the CMI, the HIR was faster than the CMI and that antibodies killed the pathogens in the HIR.'

Paper 1

Resting potential, depolarisation and the sodium-potassium pump

'A few candidates incorrectly stated that the potassium ions would enter the neurone. Candidates should always be careful to refer to the movement of ions rather than simply referring to the movement of potassium or sodium.' Many failed to link ouabain inhibition of the pump to lack of sodium gradient and prevented depolarisation.

Paper 2

Plant reproduction and embryo sac formation

'Common errors included: confusing meiosis and mitosis, referring to haploid cells rather than haploid nuclei, referring to polar bodies rather than polar nuclei, and describing the double fertilisation rather than the production of the embryo sac.'

Paper 2

Core practical methodology — dilutions, controls, aseptic technique

'Many candidates found this extremely challenging and were unable to gain any credit. The most common errors were adding a mass of gibberellin to a volume of water (instead of using the 1g per dm3 stock solution) or being out by a factor of 10.' Aseptic technique was widely listed without reasons.

Paper 3

Statistical analysis — t-tests, null hypotheses, biodiversity index

'Around a third of candidates wrote an appropriate null hypothesis that could be tested, while two thirds did not. This is an area that centres could usefully work on.' Many candidates calculated t but failed to compare it to the critical value or use the word 'significant' in the conclusion.

Paper 3

Atherosclerosis, coronary heart disease and cardiac terminology

'A lot of candidates missed out on marks they came close to achieving, due to lack of detail. Examples of this included: referring to a blood vessel rather than an artery, referring to an artery rather than a coronary artery, saying less blood reached the heart rather than reached the heart muscle or cells, not considering what happens if the heart stops contracting.'

Paper 3