Chemistry and Biology sit in the same post because, structurally, Cambridge treats them as the same subject. Identical assessment objectives, identical paper weightings, identical entry statements.

Where they differ is in what the content asks of you, and that difference is the one worth choosing on.

What the two syllabuses assume

Both entry statements are broader than students expect.

Chemistry 9701 recommends learners should have completed a course in Chemistry or Co-ordinated Science equivalent to Cambridge IGCSE or Cambridge O Level. Biology 9700 uses the same wording for Biology or Co-ordinated Science.

So a double-award science background is an accepted route into either, not a compromise. Neither statement names a grade; Cambridge frames prior study as a completed course, and any grade threshold you have been given is your school’s own policy.

Both are designed around about 360 guided learning hours for the full A Level, against roughly 130 for an IGCSE. Same figure as every other Cambridge A Level.

The structure they share

This is the part that surprises people coming from IGCSE, and it applies equally to both.

Assessment objectives, identical in both syllabuses and identical at AS and A Level:

• Knowledge and understanding: 40%
• Handling, applying and evaluating information: 40%
• Experimental skills and investigations: 20%

That last fifth is separately examined in two papers:

• Paper 3, Advanced Practical Skills. 2 hours. 23% of the AS Level, 11.5% of the A Level.
• Paper 5, Planning, Analysis and Evaluation. 1 hour 15 minutes, 30 marks. 11.5% of the A Level.

Together, practical work is 23% of your final grade in both subjects.

The line that changes how you revise

Both syllabuses attach the same note to those practical papers: the context of the questions may be outside the syllabus content.

Nothing at IGCSE works this way. In Paper 5 you can be given an investigation on material you have never studied and asked to plan it, analyse the data, and evaluate the method.

There is no chapter to revise for that. What is being assessed is whether you can think experimentally: identify the variables, judge whether a method is sound, recognise a limitation, work out what the data actually supports.

The preparation is therefore different in kind from content revision. You improve by doing practical work and writing it up properly, and by practising the reasoning on any experiment you have already done.

Where the two subjects diverge

Same skeleton, different demands.

Chemistry 9701 leans on calculation and abstraction. Moles and stoichiometry underpin large parts of the course, so arithmetic and rearranging have to be automatic. Much of the reasoning is about mechanisms you cannot see, which is a genuine conceptual step from IGCSE’s more descriptive treatment. Chemistry also prints a mathematical requirements section, in common with Physics 9702.

Biology 9700 carries more to hold in memory. Its 40% knowledge weighting is the same as Chemistry’s, but the volume of terminology and detailed process is larger, and questions frequently ask you to link concepts across topics rather than recall one. The data-handling half rewards careful reading of unfamiliar graphs and tables.

Neither is harder in the abstract. Chemistry punishes weak numeracy; Biology punishes vague, unstructured writing.

What actually changes from IGCSE

	IGCSE	A Level 9701 / 9700
Practical weighting	Modest	20% of the qualification, two papers
Practical contexts	On the syllabus	May fall outside the syllabus content
Guided learning hours	About 130	About 360
Question style	Mostly structured recall and application	40% handling and evaluating information

The hours row is doing quiet work. Three times the teaching time per subject, while your subject count drops from eight or nine to three, is a change in concentration rather than in total workload.

How to prepare before Year 12

Four things, none of which is reading ahead.

Get the arithmetic automatic, especially for Chemistry. Moles calculations, ratios, standard form, rearranging. If those are slow, they will cost chemistry marks rather than maths marks.

Write up an experiment properly. Take any practical you did at IGCSE and write it as though for Paper 5: variables, method, uncertainties, what the result supports and what it does not. That is the skill, and it can be practised without a laboratory.

Practise reading unfamiliar data. Graphs and tables about things you have not studied. Both subjects put 40% on handling and evaluating information, and the material will often be new.

Read the command words table in your syllabus. Cambridge defines exactly what Describe, Explain, Suggest and Evaluate require, and those are the definitions the mark scheme uses.

A few hours each. The summer before Year 12 is worth about twenty hours in total across all subjects, not a term’s worth of pre-reading.

The practical papers deserve a separate plan

Most students revise content and hope the practical papers look after themselves. At 23% of the A Level across Papers 3 and 5, that is a quarter of the grade left to chance.

Paper 3, Advanced Practical Skills, is 2 hours of actual laboratory work assessed under exam conditions. What it rewards is fluency with apparatus and technique, which only comes from having done things rather than read about them. If your school runs limited practical time, that is worth raising early rather than discovering in Year 13.

Paper 5, Planning, Analysis and Evaluation, needs no laboratory at all. It is 1 hour 15 minutes of written reasoning about experiments, and it can be practised anywhere. Take a published experiment, plan it yourself, then compare: which variables did you control, what would you measure, where is the largest uncertainty, what would you change.

Because both syllabuses state that question contexts may fall outside the syllabus content, this is the one part of the course where breadth of scientific reading genuinely pays. Unfamiliar contexts stop being unfamiliar if you have met a lot of them.

The mistake that costs Biology students most

One pattern is worth naming, because it is specific to 9700.

Biology rewards precision of language in a way IGCSE largely did not. With 40% of the marks on knowledge and understanding and another 40% on handling and evaluating information, an answer that gestures at the right idea in loose terms scores below one that names the process exactly.

Students arriving from IGCSE often write more and score less, because volume substituted for precision at the previous level. The fix is to write shorter answers using the syllabus’s own vocabulary, then check them against a mark scheme rather than against a textbook.

If you are taking both

Chemistry and Biology together is a common combination, and the overlap helps more than students expect.

The practical papers test the same reasoning in both subjects, so improving at Paper 5 in one improves the other. The 40/40/20 split is identical, so the way you allocate revision effort transfers directly.

The workload does not halve, though. Two sciences is about ten hours a week of taught time before independent study, and both carry heavy practical components that need doing rather than reading.

Next steps

For the third science, IGCSE to A Level Physics covers the same ground with the maths problem in front. For how the sciences compare with other subjects, which A Level subjects have the biggest jump sets them side by side using the syllabus numbers.

For the general picture, the gap between IGCSE and A Levels explains the window before term starts, and the summer before A Levels has a week-by-week plan.

Tutopiya’s A Level Preparation programme is built for that window, and you can get started with Pre-A Level Mathematics. That is a reasonable first step for a chemist in particular, given how much of 9701 rests on calculation, and more subjects are on the way. For the science-specific preparation above, the 9701 or 9700 syllabus and your own written-up practicals are the tools today.

Frequently asked questions

Is A Level Chemistry harder than IGCSE Chemistry? +

The step up is mostly in practical assessment and volume. Chemistry 9701 puts 20% of the qualification on experimental skills across two papers, and Cambridge designs each A Level around about 360 guided learning hours against roughly 130 for an IGCSE, so the subject demands close to three times the teaching time.

What does A Level Chemistry assume I already know? +

Cambridge recommends learners starting 9701 should have completed a course in Chemistry or Co-ordinated Science equivalent to Cambridge IGCSE or Cambridge O Level. Biology 9700 uses identical wording for Biology or Co-ordinated Science, so a double-award background is an accepted route into either.

Is A Level Biology or Chemistry harder? +

They share an identical mark structure: 40% knowledge and understanding, 40% handling and evaluating information, 20% experimental skills. The practical difference is in the content. Biology carries more terminology to hold, while Chemistry leans harder on calculation and abstract mechanism.

How much practical work is in A Level Biology and Chemistry? +

Twenty per cent of the qualification in both. Paper 3, Advanced Practical Skills, runs 2 hours and is worth 11.5% of the A Level. Paper 5, Planning, Analysis and Evaluation, runs 1 hour 15 for 30 marks and another 11.5%. Together they are 23% of the final grade.

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