Paper 1, 2, 3 or 4: how O Level and IGCSE science exams are built

The three Cambridge O Level sciences, Physics 5054, Chemistry 5070 and Biology 5090, share one structure. Every student sits Paper 1 and Paper 2. Then the school enters them for one of two practical papers: Paper 3 in a laboratory, or Paper 4 in writing. That makes three papers per student.

Edexcel International GCSE Biology 4BI1 and Chemistry 4CH1 are built differently. There are two papers, both sat by every student, and no laboratory exam at all. Practical skills are tested in writing inside both papers.

Not sure which of these applies? Read the code on the statement of entry first. Our guide to O Level and International GCSE explains how.

These figures are the same for 5054, 5070 and 5090 in the syllabuses for 2026, 2027 and 2028.

Paper 1 rewards speed and careful reading: forty questions in an hour is about ninety seconds each. Paper 2 holds half the marks, and it is where written explanations, calculations and diagrams score. Paper 3 and Paper 4 test practical skills in two different ways: taking and recording readings, drawing graphs, drawing conclusions and suggesting improvements.

The school decides, not the student. Both papers carry the same 20%, so neither is a shortcut.

Find out early from the school which one it has chosen, because the preparation is different:

• Paper 3 means doing experiments under time pressure: setting up apparatus, taking real readings and recording them as you go.
• Paper 4 means answering questions about experiments you are not doing: reading scales from diagrams, completing tables, plotting graphs from given data and suggesting improvements.

Even so, the skills the two papers test overlap a great deal. Our Alternative to Practical guide goes through Paper 4 section by section.

Biology 4BI1 and Chemistry 4CH1 have the same two-paper structure, and every student sits both.

Both papers mix multiple-choice, short-answer, calculation and extended open-response questions. There is no laboratory exam. Questions about practical work appear inside both papers instead, and our guide to Edexcel practicals explains how to prepare for them.

Paper 2 is shorter, but it can ask about anything in the specification, including the bold content that Paper 1 leaves out. So the bold statements need learning as well as the core.

Past papers go back many years, and the papers have not always looked the same.

• Physics 5054 and Biology 5090 changed syllabus for first examination in 2023. Papers from before 2023 were set on the earlier syllabus. They are still useful practice, but check each question's topic against the current syllabus before relying on it.
• Biology 5090 used a different number for its written practical paper. Before 2023 the Alternative to Practical was Paper 6. From 2023 it is Paper 4. If you see a 5090 Paper 6, treat it as Alternative to Practical practice.

Syllabuses for other subjects change over time too, so check the syllabus years printed on the front of any older paper.

When a topic has left the syllabus, skip its questions. When a topic is new, there will be fewer past questions on it, so give it extra attention in your own notes.

Practise the papers you will actually sit, on their real time limits.

• For Paper 1, sit whole papers against a one-hour clock. Speed is part of the test.
• For Paper 2 and the Edexcel papers, mark every written answer against the official mark scheme, point by point. Our guide on how to practise past papers sets out a method.
• For the practical paper, find out first whether it is Paper 3 or Paper 4, then practise that one.

On Eudika Learn, the past papers for Physics, Biology and Chemistry, and for Edexcel Biology and Chemistry, are arranged by paper and by year. The 5054 and 5090 question banks include real Paper 4 questions, and the 4BI1 and 4CH1 banks include Paper 1 and Paper 2. Multiple choice is marked the moment you answer. Written answers come with the mark scheme to tick against. For practical skills, the virtual labs let you take readings, fill in a table and plot the graph, though they do not replace a school laboratory.