How to Revise GCSE Science Required Practicals

A required practical question rewards understanding, not recall. For each experiment on your exam board's list, you should know what was changed, what was held constant, and what was measured. You should also be able to say how good the result actually was. GCSE science papers rarely ask you to write out a method from memory. Instead they give you a version of the practical you have not seen before. The numbers are different. The context is different. Sometimes even the equipment looks different. You are asked to name the variables, read the data, spot what went wrong, or suggest a fix. Prepare for that skill, and the required practicals stop being a weak spot. They become some of the most predictable marks on the paper.

Start by finding your board's exact list

Every exam board publishes a fixed set of practicals. The exam is guaranteed to draw questions from that list — nothing else can come up. The terms differ by board. AQA calls them "required practicals." Edexcel calls them "core practicals." OCR groups them into Practical Activity Groups, or PAGs. The names differ, but the rule is the same: the list is public and closed, so there is no real guesswork.

That makes your first task administrative, not scientific. Work out which board you sit. Check whether you are doing Combined Science, where all three sciences are assessed together, or the separate sciences, where Biology, Chemistry and Physics are graded on their own. Then pull that board's practical list and its mark schemes. Combined Science tests a smaller set of practicals than the separate GCSEs. Revising from the wrong list wastes hours on experiments you will never sit. Getting this right early is what separates focused revision from revision that only feels productive.

The mark share is bigger than most students think

Practical skills are not a minor extra in GCSE science. Ofqual's rules for GCSE sciences require that at least 15% of the marks in each science qualification test practical knowledge and skills. None of that is assessed in a lab session. It is built into the written papers, as data questions, method questions and evaluation questions across both papers.

That matters because these marks are so often half-revised. Many students learn the theory well, treat the practical work as something already covered in class, and then lose easy marks on variables, units, or reading a graph. The practical list never changes, and the question styles repeat every year. That makes this content train more like a skill than a set of facts to memorise. It is good news, because skills improve fast with focused, repeated practice.

A five-part method for revising any practical

Instead of memorising a script, run every practical through the same five questions. Write the answers down properly:

• The aim. What relationship was the experiment testing? State it as one variable affecting another, not just "to find out about X."
• The variables. Name the independent variable, which is what you changed. Name the dependent variable, which is what you measured. Name the control variables, which are what you kept fixed to make it a fair test. This one skill earns marks in almost every practical question, whatever the topic.
• The method, briefly. Show that you understand the sequence and why each step matters. You do not need to reproduce the method word for word. Ask why you filter at that point, or why a reading gets repeated.
• The results. What was measured, in what unit, and how was it processed afterwards? Think of a table, an average, or a correctly labelled graph.
• The evaluation. How reliable was the result? What would improve it next time? This is where the hardest marks sit, and it is the step students skip most.

Write those five parts from memory for one practical. Then check your answers against the specification and a real mark scheme. Whatever is missing is your real revision list. That is far more targeted than reading back through a textbook chapter.

What comes up in biology

Biology practicals reward tight control of variables and careful technique. Microscopy comes up often — preparing a slide, using a light microscope correctly, and calculating magnification and real size from an image. Food tests depend on knowing which reagent gives which colour change. Benedict's solution tests for reducing sugars. Iodine tests for starch. Biuret reagent tests for protein. The ethanol emulsion test checks for lipids. The osmosis practical, using plant tissue across a range of sugar or salt concentrations, often appears in percentage-change calculations and in questions about anomalous results. Investigating light intensity and the rate of photosynthesis brings in the inverse-square relationship. The enzyme practicals — pH or temperature against reaction rate — test how well you control every other variable. Students sitting separate Biology should also revise microbiology, including culturing microorganisms and measuring zones of inhibition around antiseptics, plus field techniques such as quadrats and transects.

What comes up in chemistry

In chemistry, marks tend to follow precision of method. Preparing a pure, dry sample of a soluble salt tests whether you understand each step. Why is the acid or base added in excess? Why is the mixture filtered? Why is it crystallised rather than simply evaporated dry? Titration is graded on the language of accuracy — reading a burette to the right precision, choosing a suitable indicator, repeating until results are concordant, and averaging only the concordant readings. Rates of reaction appear in two familiar forms: timing the volume of gas produced, and the disappearing-cross method with sodium thiosulfate. Both lead into reading a graph. Electrolysis, telling exothermic from endothermic energy changes, and paper or thin-layer chromatography with Rf value calculations complete the core content. Separate Chemistry students should also revise ion identification tests, including flame tests and the colours produced by precipitation reactions.

What comes up in physics

Physics practicals lean heavily on measurement, units and graphs. The resistance experiments — how wire length affects resistance, and how components behave in series versus parallel circuits — sit underneath most of the electricity topic. Know your circuit diagrams. Know why an ammeter is wired in series and a voltmeter in parallel. Force and extension, which is Hooke's law in practice, tests whether you can find the limit of proportionality and read the straight-line part of a graph. Investigating acceleration with light gates, or a trolley and ramp, links directly to the equations of motion. Specific heat capacity, the density of regular and irregular solids, and wave practicals — finding frequency and wavelength with a ripple tank or a vibrating string — complete the usual set. The skill being tested stays the same throughout: take repeat readings, use units correctly, plot data properly, and read a gradient or intercept off a line.

Evaluation questions decide the grade boundary

Evaluation is the part most students skip, and it is exactly where the higher-mark questions sit. These questions test a small, precise set of vocabulary applied to data and method. It is worth learning it properly:

• Accurate versus precise. Accurate means close to the true value. Precise means repeated readings are close to each other. The two are not the same, and questions are written to catch students who mix them up.
• Repeatable versus reproducible. Repeatable means the same person gets consistent results using the same method again. Reproducible means a different person, or a different method, gets a similar result.
• Anomalies. You should be able to spot a result that clearly breaks the pattern. Explain that it is normally left out of a mean, and that repeating it is the ideal fix.
• Random versus systematic error. Random error is reduced by repeating readings and averaging. Systematic error is a consistent offset, usually from the equipment or its setup, and averaging will not remove it.

When a question shows an unfamiliar table or graph and asks you to evaluate the method or suggest an improvement, this vocabulary is what it is testing — nothing more obscure. Working through real past-paper mark schemes to practise this language is one of the highest-return activities on the practicals. It turns knowledge students already have into marks they were previously losing.

Building a revision routine that sticks

Spread practical revision across the year instead of leaving it for the final weeks. Take one practical at a time. Write the five-part breakdown from memory, then check it against the specification and a mark scheme. Bring in past-paper practical questions early, because the exam version of a practical is always a variation on the one you did in class. Spotting that variation is the real skill being tested. Reconstructing the variables and method from a blank page is more useful than re-reading notes, since the exam asks you to produce an answer, not recognise a familiar one. A little of this, done consistently and started early, beats one long cramming session before the exam.

Choosing a tutor who actually knows your board

If you want extra help, the required practicals are a good test of whether a tutor knows the subject in real depth. Ask which board they know and which practicals it assesses. A tutor who knows the content will answer at once and specifically. On Tutorwise, that judgement does not have to rest on a self-written profile. Every tutor's credibility score is computed from verified signals: confirmed identity and a DBS check, verified qualifications, and a real history of teaching and reviews. You can compare tutors on evidence before you ever book a session. Use a first session, and a board-specific question of your own, to confirm the fit before committing further.

More on GCSE science and revision

• GCSE Biology Exam Preparation
• GCSE Chemistry Exam Preparation
• GCSE Physics Exam Preparation
• How to Use Past Papers Without Wasting Them