The specification (H420) is divided into six modules, assessed across three terminal papers:
Unlike some other boards, OCR tends to be consistent, with most topics appearing annually—partly due to the inclusion of a 15-mark multiple-choice section in Papers 1 and 2. A Level Biology for OCR A
Topics are structured to build foundational knowledge first (Module 2) before moving into complex systems, making it easier for students to see the "big picture" of biological concepts. The specification (H420) is divided into six modules,
Foundations in biology (cells, biological molecules, enzymes). Module 3: Exchange and transport. Module 4: Biodiversity, evolution, and disease. Module 5: Communication, homeostasis, and energy. Module 6: Genetics, evolution, and ecosystems. Content Covered Paper 1 Biological Processes Modules 1, 2, 3, & 5 Paper 2 Biological Diversity Modules 1, 2, 4, & 6 Paper 3 Unified Biology All Modules (1–6) Key Strengths Module 3: Exchange and transport