GCSE Science Required Practicals: The Complete Exam Guide

GCSE science required practicals are one of the most misunderstood parts of the science curriculum. Many parents and students assume there is a separate practical exam where lab skills are tested under timed conditions. There is not. Every required practical is assessed through written questions in the final exam papers, and those questions account for a significant chunk of the total marks.

This guide lists every AQA required practical for Biology, Chemistry and Physics, explains exactly how practicals are assessed in the GCSE, marks which ones are Combined-only and which are Triple-only, and gives your child practical strategies for answering these questions confidently. If your child takes Edexcel or OCR, the core skills are the same, and we cover the differences at the end.

How Are GCSE Science Required Practicals Assessed?

There is no practical exam. There is no separate component. There are no marks for what your child does in the laboratory. This is the single most important thing to understand about how practicals are assessed at GCSE.

Instead, the knowledge and skills from required practicals are tested through written questions scattered across the final exam papers. Your child performs the practicals in class during Years 10 and 11 to learn the methods, understand the underlying science, and develop practical skills. The exam then checks whether they understood what they did and, critically, why they did it.

When I worked in tutoring, this was a consistent blind spot. Students would tell me they “did the practical in class” and assumed that was enough. But doing the practical and being able to write about it under exam conditions are two very different things. The students who scored highest on practical questions were the ones who revised the methods as if they were learning theory, not just relying on memory of a single classroom session months earlier.

What Practical Questions Look Like

Practical questions in the exam take several forms, and they can appear in any topic area, not just the one where the practical sits:

• “Describe a method to investigate...” (6 marks, extended response)
• “Identify the independent variable” (1 mark)
• “Explain why the student repeated the experiment three times” (2 marks)
• “Plot a graph of the results shown in the table” (3–4 marks)
• “Evaluate the method and suggest improvements” (4–6 marks)
• “Calculate the rate of reaction from the graph” (2–3 marks)

The 6-mark “describe a method” question is the highest-value practical question and appears on almost every science paper. We cover how to answer it in detail below.

The 15% Rule

AQA's specification states that at least 15% of the total marks across all exam papers will be drawn from practical knowledge. For a Combined Science student sitting six papers worth a total of around 400 marks, that means at least 60 marks will test practical skills. For Triple Science students, the proportion is similar across their six higher-level papers.

These are not niche questions your child can afford to skip. They are woven throughout the papers, appearing in almost every topic. A student who ignores practical revision is leaving a significant number of marks on the table.

How Many Required Practicals Are There?

The number of GCSE science required practicals depends on whether your child takes Combined Science or Triple Science. Here is the breakdown for AQA, the most widely used exam board for science in England:

Combined vs Triple Counts

Every practical in the Combined list also appears in Triple. Triple Science simply adds extra practicals on top. If your child is on Combined, they only need to know 21; if they are on Triple, they need all 28 from the full GCSE science practicals list.

AQA Biology Required Practicals (10)

AQA Biology has 10 required practicals. Seven are shared between Combined and Triple Science; three are Triple only. These are the practicals from the full GCSE Biology topics list that your child must know for the exam.

Paper 1 Biology Practicals

Paper 1 covers Cell Biology, Organisation, Infection and Response, and Bioenergetics. Six required practicals fall in this half of the course:

Paper 2 Biology Practicals

Paper 2 covers Homeostasis, Inheritance, Variation, Evolution, and Ecology. Four required practicals sit in this half:

AQA Chemistry Required Practicals (8)

AQA Chemistry has 8 required practicals. Seven are in Combined Science; one has elements that are Triple only. Together with the Biology and Physics lists above and below, these form the complete set of required practicals for Biology, Chemistry and Physics. Chemistry practicals tend to involve precise measurement techniques, hazard awareness and careful recording of observations.

Paper 1 Chemistry Practicals

Paper 1 covers Atomic Structure, Bonding, Quantitative Chemistry, Chemical Changes and Energy Changes. Four required practicals fall here:

Paper 2 Chemistry Practicals

Paper 2 covers Rate and Extent of Chemical Change, Organic Chemistry, Chemical Analysis, Chemistry of the Atmosphere and Using Resources:

AQA Physics Required Practicals (10)

AQA Physics has 10 required practicals. Seven are shared with Combined Science; three have Triple-only elements. Physics practicals typically involve measurements, calculations and graph plotting, so they lean heavily on maths skills.

Paper 1 Physics Practicals

Paper 1 covers Energy, Electricity, Particle Model of Matter and Atomic Structure. Five required practicals sit here:

Paper 2 Physics Practicals

Paper 2 covers Forces, Waves, Magnetism and Space. Five required practicals fall here:

Key Practical Skills Tested in the Exam

The exam does not just check whether your child remembers the method. It tests a broader set of practical skills that apply across all experiments. Understanding these skills is as important as knowing the individual practicals.

Maths Skills in Practical Questions

Practical questions frequently require mathematical calculations. These come up across all three sciences and are worth learning alongside the practical methods:

• Percentage change (osmosis, growth experiments): ((new value - original value) \u00F7 original value) \u00D7 100
• Rate of reaction: amount of product \u00F7 time, or 1 \u00F7 time
• Magnification (microscopy): image size \u00F7 actual size
• Rf values (chromatography): distance moved by substance \u00F7 distance moved by solvent
• Spring constant (Hooke\u2019s law): force \u00F7 extension
• Density: mass \u00F7 volume
• Resistance: voltage \u00F7 current
• Calculating means: add values, divide by number of readings, ignoring anomalies

A student who can do the maths confidently will find practical questions much more straightforward. If your child finds these calculations tricky, it is worth practising them as standalone exercises before combining them with full practical questions.

How to Answer Practical Questions

Having worked with students preparing for science GCSEs, the pattern I noticed is that most students know what the practical involves but lose marks because they do not know how to write about it under exam conditions. Here are the two highest-value question types and exactly how to answer them.

The 6-Mark “Describe a Method” Question

This question appears on almost every science paper and is worth 6 marks. A strong method answer follows a consistent structure:

Variable Identification

Variable questions appear constantly. Your child needs to identify three types of variable for any experiment:

A quick trick: read the title of the investigation. “Investigate the effect of temperature on the rate of enzyme activity” tells you immediately that temperature is the independent variable (what you change) and enzyme activity (or time taken) is the dependent variable (what you measure). Everything else (pH, concentration, volume) must be controlled.

For graph questions, remember: the independent variable goes on the x-axis and the dependent variable goes on the y-axis. Use more than half the graph paper, choose sensible scales, and draw a line of best fit (not dot-to-dot unless told otherwise). These are among the most commonly dropped marks in science.

Edexcel and OCR: What Changes?

If your child's school uses Edexcel or OCR rather than AQA, the core practical skills are identical. The difference is in which specific experiments are listed and how they are labelled.

The critical point is this: the skills are the same across every exam board. If your child can describe a method, identify variables, plot a graph, evaluate results and suggest improvements, they can answer practical questions regardless of whether they follow AQA, Edexcel or OCR. The specific experiments are the vehicle; the practical skills are what the exam actually tests.

How Parents Can Help

You do not need a science background to support your child with required practicals. Here are specific, practical things you can do:

One pattern I saw repeatedly in tutoring: students who could talk through a practical confidently almost always scored well on practical questions in exams. The ones who struggled were those who remembered vague fragments but could not reconstruct the method logically. Encouraging your child to explain practicals out loud, to you or to themselves, is one of the simplest and most effective revision techniques.