OCR A-Level Biology A Past Papers & Mark Schemes

OCR A-Level Biology A (H420) structures its content around six modules, examined across three papers that each take a different approach to assessing biological knowledge. Rather than simply splitting content by topic, the papers are designed to test different cognitive skills — from detailed knowledge recall to synoptic reasoning. Paper 1: Biological Processes (H420/01, 2 hours 15 minutes, 100 marks, 37%) draws from Modules 2, 3, and 5. Module 2 covers foundations of biology: biological molecules, nucleic acids, enzymes, and cell structure. Module 3 covers exchange and transport: gas exchange surfaces, transport in animals (the heart and circulatory system), and transport in plants (xylem and phloem). Module 5 covers communication, homeostasis, and energy: neuronal communication, hormonal control, excretion (the kidney), photosynthesis, and respiration. Paper 2: Biological Diversity (H420/02, 2 hours 15 minutes, 100 marks, 37%) draws from Modules 2, 4, and 6. Module 4 covers biodiversity, evolution, and disease: classification, biodiversity indices, evolution by natural selection, communicable diseases, and the immune response. Module 6 covers genetics, evolution, and ecosystems: cellular control (gene expression, mutations), patterns of inheritance, manipulating genomes (genetic engineering, PCR, gel electrophoresis), cloning, and ecosystems (energy flow, nutrient cycling, succession). Paper 3: Unified Biology (H420/03, 1 hour 30 minutes, 70 marks, 26%) is a synoptic paper drawing on content from all six modules. It includes structured questions, extended-response questions, and a comprehension passage requiring students to interpret unfamiliar scientific information and connect it to their specification knowledge. The Practical Endorsement (assessed separately, pass/fail) covers a minimum of 12 practical activities. It does not contribute to the grade but is reported alongside it on the certificate.