Edexcel GCSE Biology (1BI0) Past Papers 2026

Biology 1 — Foundation and Higher Tier

Duration: 1h 45m

Biology 2 — Foundation and Higher Tier

Duration: 1h 45m

Enzyme action — denaturation, active site change, substrate fit

Every report flags incomplete enzyme explanations. Candidates state 'denatured' but fail to link this to the active site changing shape or the substrate not fitting. The full chain — denature → active site change → no enzyme-substrate complexes — is required for full marks but rarely all three points appear.

Paper 1F, Paper 1H, Paper 2F

Food tests — Benedict's heating requirement and colour changes

Omitting the heating step for Benedict's was the single most common food test error across all 2023 and 2024 Paper 2 reports. Many candidates also boiled both Benedict's and Biuret (only Benedict's needs heat) or added iodine solution despite being told to use Benedict's and Biuret.

Paper 2F, Paper 2H

Osmosis — specifying water movement and direction clearly

Candidates consistently said 'particles' or 'molecules' move without specifying water, or described the solute concentration gradient instead of the water concentration gradient. Many failed to include 'partially permeable membrane' for the final mark.

Paper 2F, Paper 2H

Core practical knowledge — controls, controlled variables, and accuracy

Candidates regularly confused a 'control experiment' (same setup without the variable being tested) with 'controlling a variable' (keeping something the same). Examiners explicitly flagged this confusion in Paper 2H in both 2023 and 2024. Repeating measurements does not improve accuracy.

Paper 1H, Paper 2F, Paper 2H

Genetics — using correct allele letters and showing sex chromosomes

Candidates used different letters from those given in the question, earning no marks for the Punnett square. In sex-linked inheritance, alleles were placed on the Y chromosome or sex chromosomes were omitted entirely. Confusing genotype with phenotype was common at Foundation.

Paper 1F, Paper 1H

Urea production — made in the liver, not the kidneys

Stating that urea is made in the kidneys was the most common error in every report covering this topic. Urea is produced in the LIVER by deamination of excess amino acids; the kidneys filter it from the blood.

Paper 2F, Paper 2H

Scientific units in practical answers — 'volume' and 'mass' not 'amount'

Examiners explicitly stated they do not credit 'amount' in practical questions. This recurring issue was flagged in Paper 2H (2023), Paper 2F (2024), and Paper 2H (2024). Controlled variables must specify volume, mass, length, or concentration.

Paper 2F, Paper 2H

Higher tier only — translation, transcription, monoclonal antibodies, ADH

Higher specification points such as describing the role of codons and tRNA in translation, how mutations in the non-coding region reduce mRNA production, and the mechanism of pregnancy testing with monoclonal antibodies consistently showed wider variation in candidate performance, with lower-ability candidates unable to extend beyond one mark.

Paper 1H, Paper 2H