OCR GCSE Combined Science A: Gateway Science (J250): complete guide to biology, chemistry, physics and the exams

OCR GCSE Combined Science A: Gateway Science (specification J250) is a double award worth two GCSE grades, covering biology, chemistry and physics. It is a linear course assessed by six written papers at the end of the course, with no coursework. This page is the index: below is a map of the three sciences, the exam structure, the tiers, and how to study each one.

The three sciences

The content is split across the three sciences. Each science has two overview pages here (one per exam paper pairing), and each overview links to a focused answer page for every topic.

Biology (six topics, B1 to B6)

Cell level systems, Scaling up, Organism level systems, Community level systems, Genes, inheritance and selection, and Global challenges. Start with the Biology cells and transport overview and the Biology organisms and ecosystems overview.

Chemistry (six topics, C1 to C6)

Particles, Elements, compounds and mixtures, Chemical reactions, Predicting and identifying reactions and products, Monitoring and controlling chemical reactions, and Global challenges. Start with the Chemistry particles and bonding overview and the Chemistry reactions and analysis overview.

Physics (six topics, P1 to P6)

Matter, Forces, Electricity and magnetism, Waves and radioactivity, Energy, and Global challenges. Start with the Physics matter, forces and energy overview and the Physics electricity, waves and radiation overview.

Exam structure

Combined Science A is assessed by six written papers, two for each science, all sat at the end of the course. Each paper is 1 hour 10 minutes, worth 60 marks, and is one sixth (about 16.7%) of the total grade.

• Biology Paper 1 covers topics B1 to B3 (Cell level systems, Scaling up, Organism level systems).
• Biology Paper 2 covers topics B4 to B6 (Community level systems, Genes inheritance and selection, Global challenges), assuming knowledge of B1 to B3.
• Chemistry Paper 3 covers topics C1 to C3 (Particles, Elements compounds and mixtures, Chemical reactions).
• Chemistry Paper 4 covers topics C4 to C6 (Predicting and identifying reactions and products, Monitoring and controlling chemical reactions, Global challenges).
• Physics Paper 5 covers topics P1 to P3 (Matter, Forces, Electricity and magnetism).
• Physics Paper 6 covers topics P4 to P6 (Waves and radioactivity, Energy, Global challenges).

Every paper also assesses the CS7 practical skills. At least 20% of marks assess maths skills, and around 15% assess the practical activities and practical skills.

Foundation and Higher tiers

The qualification is tiered. You sit all six papers at one tier.

• Foundation tier targets grades 1-1 to 5-5 and covers the core content of all three sciences.
• Higher tier targets grades 4-4 to 9-9 and adds harder calculations and more demanding content.

Because Combined Science A is a double award, grades are reported as two numbers (for example 6-6 or 5-4) based on the total marks across all six papers.

Practical activity groups (PAGs)

There is no separate practical exam, but you must complete at least 16 practical activities organised into Practical Activity Groups (PAGs): PAGs B1 to B5 for biology, C1 to C5 for chemistry, and P1 to P6 for physics. These are listed in topic CS7, and questions across all six papers test the methods, the apparatus and techniques, and how to handle data and uncertainties.

How to study Combined Science A

Combined Science A rewards precise recall, confident calculation and clear explanation.

1. Work from the specification statements. Each numbered point is a checklist; questions are written from them.
2. Learn definitions and equations. Mark schemes reward precise wording and the recall equations in physics and chemistry.
3. Drill the maths. Moles, rates, energy and electricity calculations must be automatic.
4. Master the PAG methods. Standard practical methods and data analysis recur across all six papers.
5. Practise six-mark questions. Extended responses reward a logical, well-linked argument and the right OCR command word response.

For the official specification

OCR publishes the full specification (J250), past papers and mark schemes at ocr.org.uk. Always revise from the current specification and OCR's own past papers, because question style is board-specific.