WJEC GCSE Biology (Wales): complete guide to Unit 1, Unit 2, the practical assessment and the exams

WJEC GCSE Biology is a single GCSE for learners in Wales, graded A* to G. It is a linear course assessed by two written units at the end of the course plus a centre-based practical assessment. This page is the index: below is a map of the two units, the exam structure, the tiers, and how to study each topic.

The two written units

The content is organised into Unit 1 (sections 1.1 to 1.6) and Unit 2 (sections 2.1 to 2.8). On this site the content is grouped into six study modules, each with an overview guide that links to a focused answer page for every examinable topic.

Cells and exchange (Unit 1.1 and 1.3)

Animal and plant cell structure, specialised cells and microscopy, diffusion, osmosis and active transport, the human digestive system, digestive enzymes and food tests, and absorption. Start with the Cells and exchange overview.

Respiration and circulation (Unit 1.2 and 1.4)

Aerobic and anaerobic respiration, the respiratory system and gas exchange, the heart and blood vessels, blood and cardiovascular disease. Start with the Respiration and circulation overview.

Plants and ecosystems (Unit 1.5 and 1.6)

Photosynthesis and limiting factors, leaf structure and transport in plants, transpiration, food chains, webs and pyramids, the carbon and nitrogen cycles, and human impact and biodiversity. Start with the Plants and ecosystems overview.

Cells, genetics and evolution (Unit 2.1 to 2.4)

Classification and biodiversity, cell division and stem cells, DNA and inheritance, genetic engineering and profiling, and variation and evolution. Start with the Cells, genetics and evolution overview.

Response and regulation (Unit 2.5 and 2.6)

The nervous system and reflexes, the eye, hormones and blood glucose, plant responses and tropisms, and kidneys and homeostasis. Start with the Response and regulation overview.

Micro-organisms and disease (Unit 2.7 and 2.8)

Culturing micro-organisms and their applications, pathogens and disease, defence and the immune system, and vaccines, antibiotics and monoclonal antibodies. Start with the Micro-organisms and disease overview.

Exam structure

WJEC GCSE Biology is assessed by two written units plus a practical assessment.

• Unit 1: Cells, organ systems and ecosystems. Written exam, 1 hour 45 minutes, 80 marks, 45% of the qualification, tiered.
• Unit 2: Variation, homeostasis and micro-organisms. Written exam, 1 hour 45 minutes, 80 marks, 45% of the qualification, tiered.
• Unit 3: Practical assessment. Centre-based and marked by WJEC, 10% of the qualification, untiered, usually sat in the spring of the final year.

The written papers use a mix of short answer, structured, data response and extended writing questions, some set in a practical context. A calculator is allowed in both written papers, and mathematical and practical skills are assessed throughout.

Foundation and Higher tiers

The two written units are tiered, and you normally sit both at one tier.

• Foundation tier targets grades C to G and covers the core content of every section.
• Higher tier targets grades A to D* and adds the more demanding content, harder calculations and the most challenging extended questions.

The tier you enter sets the maximum grade you can be awarded, so choose with your teacher based on your target grade.

The practical assessment

There is no separate practical exam paper, but Unit 3 is a practical assessment worth 10% of the qualification. It is untiered and marked by WJEC. You complete a scientific enquiry with a practical task and a written task, drawing on the standard methods used through the course: investigating osmosis in plant tissue, food tests, testing a leaf for starch and the rate of photosynthesis, enzyme experiments, and culturing micro-organisms with aseptic technique. Learn the methods, the control variables and how to record and analyse data.

How to study WJEC Biology

WJEC Biology rewards precise recall, links between structure and function, and confident data handling.

1. Work from the specification statements. Each numbered point is a checklist; questions are written from them.
2. Learn definitions precisely. Mark schemes reward exact wording for terms like diffusion, osmosis, homeostasis, allele and biodiversity.
3. Drill the maths. Magnification, percentage change, rates from graphs and genetic ratios all appear.
4. Master the practical methods. Osmosis, food tests, photosynthesis, enzymes and microbiology recur in the practical assessment and in data response questions.
5. Practise extended writing questions. The longer questions reward a logical, well-linked argument and the right WJEC command word response.

For the official specification

WJEC publishes the full specification, past papers and mark schemes at wjec.co.uk. Always revise from the current specification and WJEC's own past papers, because question style is board-specific.