AQA A Level Biology (7402) Past Papers 2026

7402/1 — Biological Processes

Duration: 2h

7402/2 — Biological Diversity

Duration: 2h

7402/3 — Practical and Synoptic

Duration: 2h

Virus structure and replication

In 2023, fewer than 10% of students identified three structural features found in all viruses; only 15% correctly defined 'acellular'. Common errors: naming structures found only in some viruses (reverse transcriptase, lipid envelope), confusing virus structures with bacterial structures, stating all viruses have DNA or all have RNA. Replication steps consistently omitted viral assembly before release.

Paper 1

Sucrose co-transport and phloem loading

In 2022 Q09.1, only a third of students used 'mass flow' correctly; many described diffusion 'along a pressure gradient' instead. Precise details of H⁺ co-transport into phloem tubes were poorly known. Students often failed to name the sink as 'cells' rather than a vague 'sink', and confused facilitated diffusion with simple diffusion at the sink.

Paper 1

Calvin cycle intermediates — triose phosphate (not 'TP') and RuBP regeneration

In Paper 2 (2022 Q01.2) fewer than 1 in 10 students obtained maximum marks on the light-independent reaction. TP as an abbreviation for triose phosphate is not in the specification and was penalised. Students confused GP with glucose phosphate, wrote 'reduced NAD' instead of 'reduced NADP', and described triose phosphate as oxidised rather than reduced.

Paper 2, Paper 3

ADH action — receptor location and blood pressure baroreceptors

In 2023 Q06.4, only 10% achieved maximum marks. Very few students correctly named the location of blood pressure receptors (carotid sinus / aortic arch baroreceptors). Hypothalamus and pituitary gland were the most common wrong answers. Many students provided excessive details of aquaporins without naming the correct baroreceptor location.

Paper 2

Control of gene expression — epigenetics, methylation, and transcription factors

In 2022 Q10.5, only 5% gained maximum marks; 37% gained at least one mark. Methylation and acetylation were known but students did not give sufficient mechanistic detail. Students incorrectly described 'genes being switched on' rather than using the terms 'transcription' or 'expression'. Confusion between oncogenes and proto-oncogenes also cost marks.

Paper 2

Hardy-Weinberg principle — conditions required and applying p² + 2pq + q² = 1

In 2023 Q06.6, 69% scored zero marks. Students confused Hardy-Weinberg conditions with mark-release-recapture requirements; some stated 'there cannot be any births or deaths'. The correct condition most often missed was 'random mating'. In Paper 2 Q04.4, approximately 70% of students did not gain a mark, most commonly because they assumed p or p² = 0.36 rather than correctly deriving p from q.

Paper 3

Respirometer design — measuring RQ and interpreting volume/pressure changes

In 2022 Q04.4, only 2% obtained maximum marks; the most common error was suggesting a syringe addition rather than changing the contents of the apparatus. Many students incorrectly predicted the liquid would move to the right when measuring CO₂, not recognising that without KOH the net gas change (CO₂ produced minus O₂ consumed) must be calculated to find RQ.

Paper 2

Meiosis and genetic variation — crossing over, independent assortment, and homologous pairing

In 2023 Q10.3, few students achieved 4 marks. Homologous pairing was frequently omitted from crossing-over descriptions, preventing the mark. Students described random fertilisation without specifying 'of gametes'. Many described how natural selection changes allele frequencies rather than how meiosis and fertilisation produce new allele combinations — missing the key distinction.

Paper 1