OCR A Level Biology Course Overview¶

Full-course revision notes covering OCR A Level Biology assessment structure, module links and the topic map for Modules 1 to 6.

Qualification Summary¶

Field	Detail
Qualification	OCR A Level Biology A
Code	H420
Awarding body	Cambridge OCR
Specification version	4.1 (April 2026)
Total guided learning hours	360
Assessment	Linear (all exams at the end of the course) + Practical Endorsement

Assessment Structure¶

Component	Code	Content	Duration	Marks	Weighting
Biological Processes	H420/01	Modules 1, 2, 3 and 5	2 h 15 min	100	37%
Biological Diversity	H420/02	Modules 1, 2, 4 and 6	2 h 15 min	100	37%
Unified Biology	H420/03	All modules (1–6)	1 h 30 min	70	26%
Practical Endorsement	H420/04	Assessed through practical skills (PAGs)	—	Pass/Fail	Not included in grade

All three written papers assess Module 1 skills (planning, implementing, analysis, evaluation) embedded in biological contexts drawn from the content modules.

Module Map¶

AS Level Modules (Modules 1–4, shared with H020)¶

A Level-Only Modules (Modules 5–6)¶

Topic Map: Full A Level¶

Module 5: Communication, homeostasis and energy¶

Topic code	Topic name
5.1.1	Communication and homeostasis
5.1.2	Excretion as an example of homeostatic control
5.1.3	Neuronal communication
5.1.4	Hormonal communication
5.1.5	Plant and animal responses
5.2.1	Photosynthesis
5.2.2	Respiration

Module 6: Genetics, evolution and ecosystems¶

Topic code	Topic name
6.1.1	Cellular control
6.1.2	Patterns of inheritance
6.1.3	Manipulating genomes
6.2.1	Cloning and biotechnology
6.3.1	Ecosystems
6.3.2	Populations and sustainability

Co-Teaching Notes¶

Modules 1–4 are identical between H020 (AS) and H420 (A level). Students progressing from AS to A level continue from Module 5 without repeating Modules 1–4. The specification has been designed for co-teaching, so a single class can contain both AS and A level students in years 12–13.