OCR A-Level Biology
Explore your course, one topic at a time.
Course overview
The OCR A-Level Biology specification covers 31 topics with 848 learning objectives (H420). Use the topic browser below to explore subtopics, exam tips, common mistakes, and key terminology for each area of the course.
- 31 topics
- 250 study pages
- 848 learning objectives
Verified courseQuestions and notes checked against the official specification.
- 1,228
- verified practice questions
- 282
- verified teaching notes
- 34
- topics
Your exams
- Biological processesMonday, 7 June 2027, PM
- Biological diversityMonday, 14 June 2027, PM
- Unified biologyFriday, 18 June 2027, AM
Always confirm dates and times with your exam centre.
| Paper | Time | Marks | Weight |
|---|---|---|---|
| Biological processes | 135 min | 100 | 37% |
| Biological diversity | 135 min | 100 | 37% |
| Unified biology | 90 min | 70 | 26% |
Explore your topics
31 topics
Development of practical skills in biology4 topics
- Planning3 specification points covering (a) experimental design, including to solve problems set in a practical context, (b) identification of variables that must…9 objectives · 1 study page
- Implementing3 specification points covering (a) how to use a wide range of practical apparatus and techniques correctly, (b) appropriate units for measurements, (c)…9 objectives · 3 study pages
- Analysis6 specification points covering (a) processing, analysing and interpreting qualitative and quantitative experimental results, (b) use of appropriate…18 objectives · 4 study pages
- Evaluation5 specification points covering (a) how to evaluate results and draw conclusions, (b) the identification of anomalies in experimental measurements, (c) the…15 objectives · 2 study pages
Practical Endorsement in biology2 topics
Practical skills
Practical skills - Independent thinkingThis practical-skills statement asks you to apply investigative approaches and methods during practical work, not merely to describe them.3 objectives- Practical skills - Use and application of scientific methods and practices6 specification points covering (b) safely and correctly use a range of practical equipment and materials, (c) follow written instructions, (d) make and…18 objectives · 2 study pages
- Practical skills - Research and referencing2 specification points covering (h) use online and offline research skills including websites, textbooks and other printed scientific sources of…6 objectives · 1 study page
- Practical skills - Instruments and equipmentThis practical-skills statement asks you to select and use instruments, equipment and techniques that match the biology being investigated across the whole…3 objectives
- Use of apparatus and techniques14 specification points covering (a) use of appropriate apparatus to record a range of quantitative measurements (to include mass, time, volume,…42 objectives · 14 study pages
Foundations in biology6 topics
- Cell structure11 specification points covering (a) the use of microscopy to observe and investigate different types of cell and cell structure in a range of eukaryotic…33 objectives · 10 study pages
- Biological molecules20 specification points covering (a) how hydrogen bonding occurs between water molecules, and relate this, and other properties of water, to the roles of…61 objectives · 20 study pages
- Nucleotides and nucleic acids8 specification points covering (a) the structure of a nucleotide as the monomer from which nucleic acids are made, (b) the synthesis and breakdown of…24 objectives · 8 study pages
- Enzymes7 specification points covering (a) the role of enzymes in catalysing reactions that affect metabolism at a cellular and whole organism level, (b) the role…21 objectives · 6 study pages
- Biological membranes8 specification points covering (a) the roles of membranes within cells and at the surface of cells, (b) the fluid mosaic model of membrane structure and…24 objectives · 8 study pages
- Cell division, cell diversity and cellular organisation13 specification points covering (a) the cell cycle, (b) how the cell cycle is regulated, (c) the main stages of mitosis and related ideas.39 objectives · 13 study pages
Exchange and transport3 topics
- Exchange surfaces8 specification points covering (a) the need for specialised exchange surfaces, (b) the features of an efficient exchange surface, (c) the structures and…24 objectives · 7 study pages
- Transport in animals11 specification points covering (a) the need for transport systems in multicellular animals, (b) the different types of circulatory systems, (c) the…33 objectives · 10 study pages
- Transport in plants9 specification points covering (a) the need for transport systems in multicellular plants, (b) (i) the structure and function of the vascular system in the…27 objectives · 8 study pages
Biodiversity, evolution and disease3 topics
- Communicable diseases, disease prevention and the immune system15 specification points covering (a) the different types of pathogen that can cause communicable diseases in plants and animals, (b) the means of…45 objectives · 14 study pages
- Biodiversity10 specification points covering (a) how biodiversity may be considered at different levels, (b) (i) how sampling is used in measuring the biodiversity of a…30 objectives · 10 study pages
- Classification and evolution10 specification points covering (a) the biological classification of species, (b) the binomial system of naming species and the advantage of such a system,…30 objectives · 10 study pages
Communication, homeostasis and energy7 topics
- Communication and homeostasis4 specification points covering (a) the need for communication systems in multicellular organisms, (b) the communication between cells by cell signalling,…12 objectives · 4 study pages
- Excretion as an example of homeostatic control9 specification points covering (a) the term excretion and its importance in maintaining metabolism and homeostasis, (b) (i) the structure and functions of…27 objectives · 6 study pages
- Neuronal communication4 specification points covering (a) the roles of mammalian sensory receptors in converting different types of stimuli into nerve impulses, (b) the structure…12 objectives · 4 study pages
- Hormonal communication7 specification points covering (a) endocrine communication by hormones, (b) the structure and functions of the adrenal glands, (c) (i) the histology of the…21 objectives · 6 study pages
- Plant and animal responses14 specification points covering (a) (i) the types of plant responses, (ii) practical investigations into phototropism and geotropism, (b) the roles of…42 objectives · 12 study pages
- Photosynthesis9 specification points covering (a) the interrelationship between the process of photosynthesis and respiration, (b) the structure of a chloroplast and the…27 objectives · 9 study pages
- Respiration13 specification points covering (a) the need for cellular respiration, (b) the structure of the mitochondrion, (c) the process and site of glycolysis and…39 objectives · 13 study pages
Genetics, evolution and ecosystems6 topics
- Cellular control4 specification points covering (a) types of gene mutations and their possible effects on protein production and function, (b) the regulatory mechanisms…12 objectives · 4 study pages
- Patterns of inheritance11 specification points covering (a) (i) the contribution of both environmental and genetic factors to phenotypic variation, (ii) how sexual reproduction…33 objectives · 10 study pages
- Manipulating genomes11 specification points covering (a) the principles of DNA sequencing and new DNA sequencing techniques, (b) (i) how gene sequencing has allowed for…33 objectives · 10 study pages
- Cloning and biotechnology14 specification points covering (a) (i) natural clones in plants and the production of natural clones for use in horticulture, (ii) how to take plant…42 objectives · 10 study pages
- Ecosystems6 specification points covering (a) ecosystems, which range in size, are dynamic and are influenced by both biotic and abiotic factors, (b) biomass…19 objectives · 6 study pages
- Populations and sustainability5 specification points covering (a) the factors that determine size of a population, (b) interactions between populations, (c) the reasons for, and…15 objectives · 5 study pages
About this course
About OCR A-Level Biology
OCR A-Level Biology offers an in-depth exploration of the living world, from fundamental biochemical processes to entire ecosystems. The specification (H420) is designed to develop your scientific knowledge, practical skills, and critical thinking. Over two years, you will study topics ranging from cell structure and biological molecules to genetics, evolution, and homeostasis. The course emphasises how biology applies to real-world contexts, such as disease, conservation, and biotechnology, helping you see the subject’s relevance beyond the classroom.
A central theme of OCR Biology is the integration of practical work. You will carry out a minimum of 12 required practical activities, building skills in planning, implementing, analysing, and evaluating experiments. These are assessed through a separate Practical Endorsement, reported alongside your final grade. The curriculum also encourages mathematical and problem-solving abilities, with at least 10% of marks testing mathematical skills. This combination of theoretical depth and hands-on experience prepares you well for university study or careers in science and medicine.
The specification is structured into six teaching modules. Module 1 introduces practical skills, while Modules 2–6 cover the core content. The assessment is linear, meaning you sit all exams at the end of the two-year course. This structure allows you to build knowledge cumulatively, linking topics such as cell division, genetics, and evolution. OCR’s clear layout and detailed specification points make it easier to track your progress and focus revision. Many students appreciate the logical progression from molecules to ecosystems, which mirrors the hierarchy of biological organisation.
Assessment Structure
The qualification is assessed through three written exams at the end of the two-year linear course. Paper 1 (Biological processes, 2 hours 15 minutes, 100 marks, 37% of A-level) covers content from Modules 1, 2, 3, and 5. Paper 2 (Biological diversity, 2 hours 15 minutes, 100 marks, 37%) covers Modules 1, 2, 4, and 6. Paper 3 (Unified biology, 1 hour 30 minutes, 70 marks, 26%) draws on all modules and includes synoptic questions. There is no coursework for the final grade, but a separate Practical Endorsement is awarded based on teacher assessment of practical competencies, reported as either Pass or Not Classified alongside the A-level grade.
Why Choose OCR?
- OCR provides a highly structured specification with clear learning outcomes, making it easier to plan study and revision. The content is broken down into logical modules, and the exam papers are predictable in style, allowing for focused preparation.
- The practical endorsement is integrated meaningfully into the course, with no controlled assessment pressure. This lets you develop essential laboratory skills without the stress of examined practical work, while still gaining a certification that universities and employers value.
- OCR has a reputation for high-quality support materials, including textbooks endorsed by the board, past papers, and online resources. The assessment style rewards understanding and application rather than just recall, encouraging deeper learning and critical thinking.
Frequently Asked Questions
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Assessment and exam guidance
Assessment Objectives
Demonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures.
Apply knowledge and understanding of scientific ideas, processes, techniques and procedures in a theoretical context, in a practical context, when handling qualitative data and when handling quantitative data.
Analyse, interpret and evaluate scientific information, ideas and evidence, including in relation to issues, to make judgements and reach conclusions and to develop and refine practical design and procedures.
Exam Structure
Biological processes
2h 15m
Duration
100
Marks
37%
Weighting
Biological diversity
2h 15m
Duration
100
Marks
37%
Weighting
Unified biology
1h 30m
Duration
70
Marks
26%
Weighting
Tips and common mistakes
Common Exam Mistakes
Pitfalls to avoid in your exams
- •Confusing the independent and dependent variable: the correction is to state clearly which variable the experimenter changes and which is measured as the outcome.
- •Listing variables to control without saying how: the correction is to give a specific method of holding each one constant.
- •Treating repetition alone as improving validity: the correction is to explain that repetition improves reliability, while validity depends on measuring the right thing and controlling confounders.
- •Naming the independent variable as the one to control: the correction is to recognise that the independent variable is deliberately changed, not held constant.
- •Assuming every conceivable variable must be controlled: the correction is to control those that could realistically affect the dependent variable and justify the choice.
- •Ignoring a confounder that clearly affects the outcome: the correction is to check each option against what could influence the measured result.
- •Describing the method step by step instead of judging whether it can meet the expected outcome; correction: frame each point as a judgement about fitness for purpose.
- •Treating any safety precaution as evidence of appropriateness; correction: distinguish safety and ethics from validity and reliability of the outcome.
Top Examiner Tips
Expert advice for exam success
- •Read the practical context carefully and apply the design sequence to that specific scenario rather than giving a generic plan.
- •Name apparatus and units for the dependent variable so the measurement is clearly valid.
- •For each controlled variable, state the method of control, not just the variable name.
- •Label each variable in the scenario as independent, dependent or controlled before choosing an option.
- •Ask whether each option could affect the dependent variable; if it could and is not being changed, it needs controlling.
- •Reject distractors that are the variable being measured or deliberately changed.
- •Open by naming the expected outcome so every later judgement has a reference point.
- •Use comparative judgement language such as 'sufficient', 'adequate' or 'too coarse', each tied to a specific feature of the method.
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