Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers 2024–2025 | Papers, Mark Schemes & Examiner Advice (Updated 2026)
- Daniel White
- Mar 6
- 23 min read
Updated: Mar 19
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers are one of the most effective ways to prepare for the real exam. Below you’ll find the latest official past papers, mark schemes and grade thresholds, organised clearly so you can practise exactly like the real test.
We’ve also added insights from experienced Physics, Chemistry and Biology teachers on what actually separates A students from the rest* — mistakes examiners repeatedly see and the strategies top students use to score higher. Click here to read the teacher advice (highly recommended before you start practising). If you’re still unsure which papers, variants or tiers you should be practising, click here for our quick guide explaining exactly which past papers apply to your course.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – November 2025 | Question Papers & Answers
2025 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/11) November 2025 Past Paper | Paper 1 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/12) November 2025 Past Paper | Paper 1 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/13) November 2025 Past Paper | Paper 1 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/21) November 2025 Past Paper | Paper 2 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) November 2025 Past Paper | Paper 2 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/23) November 2025 Past Paper | Paper 2 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/31) November 2025 Past Paper | Paper 3 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) November 2025 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/33) November 2025 Past Paper | Paper 3 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/41) November 2025 Past Paper | Paper 4 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) November 2025 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/43) November 2025 Past Paper | Paper 4 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/51) November 2025 Past Paper | Paper 5 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) November 2025 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/53) November 2025 Past Paper | Paper 5 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/61) November 2025 Past Paper | Paper 6 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) November 2025 Past Paper | Paper 6 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/63) November 2025 Past Paper | Paper 6 Variant 3 | ||
What total mark was required to achieve an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 November 2025 exam?
Based on the November 2025 grade thresholds for Cambridge IGCSE Co-ordinated Sciences (0654), students taking the standard double-award route (three papers combined, 240 total marks) needed between 169–180 marks for A* and between 141–149 marks for A, depending on the exam variant (BX, BY, BZ, CX, CY or CZ). In percentage terms, this means top students scored 70–75% for A* and 59–62% for A.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – June 2025 | Question Papers & Answers
2025 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/11) June 2025 Past Paper | Paper 1 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/12) June 2025 Past Paper | Paper 1 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/13) June 2025 Past Paper | Paper 1 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/21) June 2025 Past Paper | Paper 2 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) June 2025 Past Paper | Paper 2 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/23) June 2025 Past Paper | Paper 2 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/31) June 2025 Past Paper | Paper 3 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) June 2025 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/33) June 2025 Past Paper | Paper 3 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/41) June 2025 Past Paper | Paper 4 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) June 2025 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/43) June 2025 Past Paper | Paper 4 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/51) June 2025 Past Paper | Paper 5 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) June 2025 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/53) June 2025 Past Paper | Paper 5 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/61) June 2025 Past Paper | Paper 6 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) June 2025 Past Paper | Paper 6 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/63) June 2025 Past Paper | Paper 6 Variant 3 | ||
How many total marks were needed for an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 June 2025 exam?
In the June 2025 Cambridge IGCSE Co-ordinated Sciences (0654) exam, students taking the full double-award route (240 total marks across three papers) needed between 169 and 177 marks to achieve A* and between 143 and 148 marks to achieve A, depending on the exam variant taken (BX, BY, BZ, CX, CY or CZ). In practical terms, this means students who reached the top grades scored roughly 70–74% of the total marks for A* and about 60–62% for A.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – March 2025 | Question Papers & Answers
2025 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/12) March 2025 Past Paper | Paper 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) March 2025 Past Paper | Paper 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) March 2025 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) March 2025 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) March 2025 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) March 2025 Past Paper | Paper 6 Variant 2 | ||
How many marks were needed for an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 March 2025 exam?
In the March 2025 Cambridge IGCSE Co-ordinated Sciences (0654) exam, students taking the full double-award route (240 total marks across three papers) needed 178 marks to achieve A* and 151 marks to achieve A for the available variants (BY and CY).
This means the top grades were awarded within a very tight range, with students needing about 74% of the total marks for A* and about 63% for A, showing consistently strong performance across all three science papers.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – November 2024 | Question Papers & Answers
2024 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/11) November 2024 Past Paper | Paper 1 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/12) November 2024 Past Paper | Paper 1 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/13) November 2024 Past Paper | Paper 1 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/21) November 2024 Past Paper | Paper 2 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) November 2024 Past Paper | Paper 2 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/23) November 2024 Past Paper | Paper 2 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/31) November 2024 Past Paper | Paper 3 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) November 2024 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/33) November 2024 Past Paper | Paper 3 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/41) November 2024 Past Paper | Paper 4 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) November 2024 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/43) November 2024 Past Paper | Paper 4 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/51) November 2024 Past Paper | Paper 5 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) November 2024 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/53) November 2024 Past Paper | Paper 5 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/61) November 2024 Past Paper | Paper 6 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) November 2024 Past Paper | Paper 6 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/63) November 2024 Past Paper | Paper 6 Variant 3 | ||
How many marks were needed for an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 November 2024 exam?
In the November 2024 Cambridge IGCSE Co-ordinated Sciences (0654) exam, students taking the full double-award route (240 total marks across three papers) needed between 168 and 177 marks to achieve A* and between 140 and 148 marks to achieve A, depending on the exam variant (BX, BY, BZ, CX, CY or CZ). This means the top grades were awarded within a very narrow range, with students typically needing about 70–74% of the total marks for A* and about 58–62% for A, demonstrating strong and consistent performance across all three science papers.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – June 2024 | Question Papers & Answers
2024 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/11) June 2024 Past Paper | Paper 1 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/12) June 2024 Past Paper | Paper 1 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/13) June 2024 Past Paper | Paper 1 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/21) June 2024 Past Paper | Paper 2 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) June 2024 Past Paper | Paper 2 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/23) June 2024 Past Paper | Paper 2 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/31) June 2024 Past Paper | Paper 3 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) June 2024 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/33) June 2024 Past Paper | Paper 3 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/41) June 2024 Past Paper | Paper 4 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) June 2024 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/43) June 2024 Past Paper | Paper 4 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/51) June 2024 Past Paper | Paper 5 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) June 2024 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/53) June 2024 Past Paper | Paper 5 Variant 3 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/61) June 2024 Past Paper | Paper 6 Variant 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) June 2024 Past Paper | Paper 6 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/63) June 2024 Past Paper | Paper 6 Variant 3 | ||
How many marks were needed for an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 June 2024 exam?
In the June 2024 Cambridge IGCSE Co-ordinated Sciences (0654) exam, students taking the full double-award route (240 total marks across three papers) needed between 176 and 189 marks to achieve A* and between 147 and 160 marks to achieve A, depending on the exam variant (BX, BY, BZ, CX, CY or CZ). This shows the top grades fell within a clear but narrow range, meaning students needed about 73–79% of the total marks for A* and about 61–67% for A.
Cambridge IGCSE Co-ordinated Sciences (0654) Past Papers – March 2025 | Question Papers & Answers
2024 Cambridge IGCSE Co-ordinated Sciences | Downloads | |
Cambridge IGCSE Co-ordinated Sciences (0654/12) March 2024 Past Paper | Paper 1 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/22) March 2024 Past Paper | Paper 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/32) March 2024 Past Paper | Paper 3 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/42) March 2024 Past Paper | Paper 4 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/52) March 2024 Past Paper | Paper 5 Variant 2 | ||
Cambridge IGCSE Co-ordinated Sciences (0654/62) March 2024 Past Paper | Paper 6 Variant 2 | ||
How many marks were needed for an A or A* in the Cambridge IGCSE Co-ordinated Sciences (Double Award) 0654 March 2024 exam?
IIn the March 2024 Cambridge IGCSE Co-ordinated Sciences (0654) exam, students taking the full double-award route (240 total marks across three papers) needed 172 marks to achieve A* and 146 marks to achieve A for the available variants (BY and CY).
This means the top grades were awarded within a very narrow range, with students needing about 72% of the total marks for A* and about 61% for A, demonstrating consistently strong performance across all three science papers.
Why Some Students Achieve A* in Cambridge IGCSE Co-ordinated Sciences (0654) — The Physics Mistakes That Hold Most Students Back!
After years of teaching the syllabus, our Physics teachers have identified the patterns that repeatedly appear in student answers. Many of these errors are not due to a lack of effort, but small misunderstandings in concepts, definitions, or exam technique that quickly add up during the exam. In the sections below, we first break down the most common physics mistakes seen in IGCSE Co-ordinated Sciences (0654).
Unit Conversions
This comes up again and again across the paper, and it's entirely avoidable. When a question gives you time in minutes or days, you must convert to seconds before touching a formula. When distances are in millimetres or centimetres, convert to metres first. The mark scheme is written in SI units, so if your working uses the wrong units, you'll lose the method mark even if your arithmetic is otherwise correct.
Get into the habit of scanning the stimulus before you write anything. Ask yourself: are all my values in metres, seconds, and kilograms? If not, convert them first. Writing out the formula before substituting values is also genuinely useful here — it forces you to think about what each quantity should look like, and you'll spot unit mismatches before they cost you.
Reading Speed-Time and Extension-Load Graphs
Two specific misunderstandings crop up regularly with graphical questions.
On speed-time graphs, many candidates try to read off a single value and use it directly, when the question is actually asking for distance. Distance is the area under the line — not a point on the graph. Break the shape into triangles and rectangles, calculate each area separately, then add them together. This is a technique worth practising until it's automatic.
On spring questions, watch out for the difference between length and extension. The graph may show total length on one axis, but Hooke's Law requires the extension — that is, how much the spring has stretched from its natural length. Always identify the original (unloaded) length from the graph first, then subtract it from the loaded length. Using the total length in your calculation is one of the most common errors on this type of question, and it will give you a completely wrong answer even if your substitution into F = ke is otherwise perfect.
Echo and Wave Calculations
The echo calculation catches candidates out more often than it should. If you're finding the speed of sound from an echo, remember that the sound makes a return journey — it travels to the wall and back again. The distance you measure or are given is only half the total path. Drawing a quick sketch of the situation, with an arrow going out and another coming back, takes ten seconds and will stop you from making this error.
On wave diagrams, amplitude causes consistent confusion. Some candidates measure it as the full height from trough to crest — that's the wrong approach. Amplitude is the distance from the equilibrium position (the undisturbed centre line) to either the crest or the trough. When you're working with wave diagrams, mark the equilibrium line explicitly before you take any measurement. Don't confuse this with wavelength, which is the horizontal distance for one complete cycle.
Parallel Circuits
This topic requires you to hold a counterintuitive idea firmly in your mind: adding more resistors in parallel reduces the total resistance of the circuit. Many candidates assume the opposite, reasoning that more components must mean more resistance. That logic applies to series circuits, not parallel ones. Each additional parallel branch gives current another path to flow through, so the overall opposition to current decreases.
On circuit diagram questions, take care with voltmeter placement. Before you answer, trace the leads of the voltmeter back to the circuit and identify precisely which component they sit across. In questions involving both a thermistor and a fixed resistor, the voltmeter is often measuring the fixed resistor — and candidates regularly assume it's measuring the variable component instead. Trace first, then answer.
Nuclear Decay and Half-Life
Beta decay is consistently misremembered. During β⁻ emission, a neutron inside the nucleus converts into a proton. This means the proton number goes up by one, not down — the nucleon number stays the same because you've simply changed the type of nucleon, not the total count. Write this out as a transformation (n → p + β⁻) until it sticks.
For half-life calculations, resist the temptation to divide the final activity by the elapsed time. That gives you a meaningless number. Instead, work through the problem step by step: start with the initial activity, halve it, note the time, halve again, note the time, and continue until you reach the value given in the question. A simple two-column table — time in one column, activity in the other — makes this mechanical and error-free.
A Note on Graph Drawing
When plotting graphs, your scale must be linear and, where appropriate, should start at the origin. A line of best fit is a single smooth line drawn through the general trend of the data — it is emphatically not a dot-to-dot connection between plotted points. If you're asked to find a gradient, draw a large triangle directly on the graph and show the rise and run values clearly. Examiners need to see your working, and a larger triangle reduces the proportional effect of any reading error.
Why Some Students Get A* in IGCSE Co-ordinated Sciences (0654) — And Others UnfortunatelyDon’t! (According to Your Chemistry Teachers)
Our Chemistry teachers have also shared their key insights into the mistakes students make most often in Cambridge IGCSE Co-ordinated Sciences. Chemistry is a subject where small misunderstandings can lead to major mistakes, whether in balancing equations, interpreting practical results, identifying ions, or applying key ideas accurately under exam pressure.
In the next section, pay very close attention to these points. Our Chemistry teachers have written their most important insights to help you recognise these pitfalls early, avoid the most common errors, and improve your marks more effectively.
Electrolysis of Aqueous Solutions
This is one of the most reliably tested topics on the paper, and the same error appears time and again. When candidates are asked to predict the product at the cathode during the electrolysis of an aqueous solution, many simply name the metal from the salt — so for aqueous sodium chloride, they write sodium. This is incorrect, and it reflects a failure to think carefully about what's actually present in the solution.
The key distinction is between molten and aqueous conditions. In a molten ionic compound, the only ions available are those from the compound itself, so yes — the metal ion would be discharged at the cathode. But in an aqueous solution, water is also present, and water provides hydrogen ions (H⁺). When the metal in the salt is a reactive one — sodium, potassium, calcium, for instance — those metal ions are not preferentially discharged. The hydrogen ions are reduced instead, and hydrogen gas is produced at the cathode. Make this a two-step habit: identify the conditions, then identify all the ions present before deciding what's discharged.
Exothermic and Endothermic Reactions
The confusion here is straightforward to resolve, but candidates consistently get it backwards — particularly with endothermic reactions. An endothermic reaction absorbs energy from the surroundings. That energy is being drawn in to break bonds, which means the surroundings — including the solution in the test tube — become cooler. The temperature of the reaction mixture goes down. Many candidates assume the opposite, perhaps reasoning that if a reaction is "taking in" energy, something must be getting hotter. It isn't.
Exothermic reactions release energy to the surroundings, which is why the test tube feels warm and the temperature of the mixture rises. A useful anchor: exo means out, as in exit. Heat exits the reaction and enters the surroundings — temperature goes up. With endothermic reactions, the reverse is true. If you can keep that directionality clear, the temperature change follows automatically.
Metallic and Non-metallic Oxides
This is a case where a straightforward rule is being reversed, and it costs marks unnecessarily. Metal oxides are basic — magnesium oxide, copper oxide, sodium oxide all fall into this category. Non-metal oxides are acidic — sulfur dioxide, carbon dioxide, nitrogen dioxide. The pattern follows directly from position in the Periodic Table: metals sit to the left, their oxides are basic; non-metals sit to the right, their oxides are acidic.
What seems to trip candidates up is an intuitive but incorrect assumption — perhaps that metals, being "stronger" or more dominant elements, must produce the more aggressive type of oxide. Don't reason from intuition here; simply learn the rule and apply it consistently. If a question asks you to predict whether an oxide will turn litmus red or blue, or whether it will react with an acid or an alkali, this one rule is all you need to get started.
Qualitative Analysis and Chemical Tests
Marks in this area are lost in two distinct ways — through poor practical technique and through muddled recall of specific tests.
On flame tests: if you use a yellow Bunsen flame, you will not see the colour produced by the metal ion, because the yellow swamps everything else. Always use a roaring blue flame. This is not a minor detail — it determines whether the test is even valid.
For gas tests, the two most commonly confused are oxygen and hydrogen, and the distinction is precise. A glowing splint relights in oxygen — the splint is already extinguished when you introduce it. A lighted splint produces a squeaky pop in hydrogen — the splint is burning when you hold it to the gas. Muddling these two will cost you the mark even if you identify the correct gas, because the test described must match the observation.
For testing whether a liquid is water, anhydrous copper(II) sulfate is the reagent — it turns from white to blue in the presence of water. Candidates sometimes omit this test entirely or describe cobalt chloride paper without specifying that it must be anhydrous cobalt chloride paper (blue to pink). Either is acceptable, but the detail matters.
Molecular Formulae and Relative Molecular Mass
Errors here tend to fall into one of two categories: forgetting to account for subscripts, or ignoring atomic masses altogether.
On Mr calculations, the method must be systematic. Take every element in the formula, find its relative atomic mass from the Periodic Table, multiply by the number of atoms of that element present, then sum everything together. For CO₂, that means one carbon plus two oxygens — 12 + (2 × 16) = 44. A surprising number of candidates calculate this as 12 + 16 = 28, simply forgetting that the subscript tells you how many atoms are present. Go through the formula symbol by symbol and account for every atom before you add anything up.
The other mistake is more fundamental: some candidates add up the total number of atoms in the formula and treat that number as the Mr. That approach ignores atomic mass entirely and will give you the wrong answer for virtually every compound. The Periodic Table is provided precisely so you can look up these values — use it. In organic chemistry, a separate issue arises when drawing structural formulae for alkenes. Ethene is a common example where the double bond is simply omitted, leaving a structure that actually represents ethane. The way to check your drawing is to count the bonds around each carbon atom — there must be exactly four. If a carbon in your structure only has three bonds, something is missing, and in an alkene that missing bond is almost always the second bond of the double bond. Apply this four-bond check to every carbon before you commit to your answer.
Why Some Students Achieve A* in Cambridge IGCSE Co-ordinated Sciences (0654) — And Others Are Unable To! (According to Your Biology Teacher)
Finally, our Biology teachers have also highlighted several recurring mistakes that appear year after year in Cambridge IGCSE Co-ordinated Sciences exams. Based on years of teaching experience, they have also given their advice below.
Pay close attention to the points below, as avoiding these common errors can make a noticeable difference to your final score.
Describing Osmosis
Precision of language is everything on this topic, and there are two specific ways candidates lose marks that are entirely avoidable.
The first is describing the movement of the wrong substance. Osmosis is the movement of water — not salt, not sugar, not the solute. If your answer describes sugar molecules moving across the membrane, you have described diffusion of a solute, not osmosis, and you will not receive the mark. Keep the solute out of your description entirely.
The second issue is the phrase "water concentration." Examiners are looking for "water potential," and the two are not interchangeable in a mark scheme context. Water potential is the precise thermodynamic term, and using it signals that you understand the concept correctly. The full definition worth committing to memory is: osmosis is the movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane. Every part of that sentence is doing work — the direction, the membrane, and the term water potential are all expected.
Respiration and Energy Release
Two distinct errors appear here, and both come down to incomplete phrasing rather than a fundamental misunderstanding.
When comparing aerobic and anaerobic respiration, many candidates write that anaerobic respiration "releases less energy" and leave it there. That statement is incomplete. The examiner needs you to specify less energy per glucose molecule — because the comparison only makes sense relative to the same starting material. Train yourself to add that phrase automatically whenever you make this comparison.
The products of aerobic respiration also catch candidates out. Carbon dioxide and water are both produced, and both need to be stated. Candidates sometimes mention only one, or introduce incorrect products. Link the products to what you know about the reactants: glucose and oxygen go in, carbon dioxide and water come out, and a substantial amount of energy is released in the process. That energy is what drives energy-requiring processes such as active transport and protein synthesis — and if a question asks you to explain why aerobic respiration is needed for a particular cellular process, making that link explicitly is what earns the mark.
Anatomical and Structural Confusion
Misidentification of structures costs marks on questions that are otherwise straightforward, and the errors tend to cluster around the same few areas. The trachea and oesophagus are distinct in both function and position — the trachea carries air to the lungs, the oesophagus carries food to the stomach — yet they are regularly confused in written answers. Similarly, the diaphragm and rib cage are both involved in breathing, but they are separate structures with separate roles. The diaphragm is a sheet of muscle below the lungs; the rib cage is the bony structure surrounding them. If a question asks about the mechanism of ventilation, you need to be specific about which structure is moving and in which direction.
In heart anatomy, the left ventricle has the thickest, most muscular wall of the four chambers. The reason is functional: it must generate sufficient pressure to pump oxygenated blood around the entire body via the aorta. The right ventricle only pumps blood to the lungs, a much shorter distance requiring far less pressure. If you can explain why the wall is thicker, rather than simply stating that it is, you are much better placed to answer application questions.
In the reproductive system, be precise about location. Meiosis occurs in the testes to produce sperm. Questions about semen require you to distinguish between the sperm cells themselves and the fluid they are carried in — knowing that accessory glands contribute fluid to form semen is the level of detail that separates complete answers from partial ones.
Monomers and Biological Polymers
The confusion here usually stems from mixing up the components of different biological molecules, and glycogen is the most common casualty. Glycogen is a storage polysaccharide made entirely from glucose — not from glycerol, not from fatty acids. Those belong to fats. A candidate who writes that glycogen is built from fatty acids has conflated two completely different classes of biological molecule.
The relationships worth knowing with complete confidence are these: starch and glycogen are both made from glucose; proteins are made from amino acids; fats and oils are made from fatty acids and glycerol. If you organise these into a simple table during revision and test yourself on it regularly, this becomes one of the most reliable sources of marks on the paper rather than one of the most common sources of errors.
Using Precise Biological Terminology
Vague language is one of the most consistent reasons candidates miss marks on questions they clearly understand. The knowledge is there — but the answer isn't expressed with enough precision to satisfy the mark scheme.
The definition of a gene is a good example. "A length of DNA" is not wrong, but it is incomplete. A gene is a sequence of DNA that codes for a protein. That second half of the definition is what the mark is awarded for, and it's what most candidates leave out. Similarly, when discussing white blood cells and immune responses, using the word "bacteria" or "germs" where the mark scheme expects "pathogen" will cost you the mark even though your underlying understanding is correct. Pathogens are disease-causing organisms — bacteria, viruses, fungi — and that term should appear automatically whenever you write about infection, immunity, or disease.
This pattern repeats across a number of key terms on the syllabus. Assimilation, meiosis, transpiration, active transport — these all have definitions with specific wording that examiners are looking for. "Learning" a definition loosely is not sufficient; you need to be able to reproduce the key components accurately under exam conditions.
The most effective approach is to build a personal glossary of syllabus definitions and test yourself on them regularly — not by reading them, but by writing them from memory and then checking. If you can write the definition of a gene, a pathogen, and meiosis correctly without looking, you've converted a common source of lost marks into reliable ones. That kind of precision, applied consistently across your answers, is what distinguishes a good response from an excellent one.
The syllabus changed in 2025 — can I still use the above past papers from before 2025 to revise?
You can use them, but with caution. Past papers from 2024 and earlier were written for a different syllabus, so some questions will cover topics that have been removed, and they won't include newer topics like Space Physics (P6) or the expanded Diseases and Immunity section in Biology. Use older past papers to practise exam technique and familiar topics, but always cross-check questions against the 2025–2027 syllabus to make sure the content is still relevant before spending time on it.
The 2026 papers look different from the ones I've been practising with — has anything actually changed?
Only the appearance has changed, not the content. From March 2026, Cambridge is using a new accessible design with clearer fonts, better spacing, and improved layouts. The topics, question types, difficulty level, and marks are all exactly the same as in 2025. So if you've been practising with 2025 papers, you are fully prepared — the new look is just easier on the eyes.
I'm so confused. There are so many syllabus codes and names — how do I know which Cambridge Science course I'm actually doing?
Check the syllabus code — it's the most important thing to identify. If your code is 0654 or 0973, you are doing Co-ordinated Science (Double Award), which means you'll receive two IGCSE grades at the end (e.g., AA or 9-9). If your code is 0653, you are doing Combined Science (Single Award) and will receive just one IGCSE grade. The difference between 0654 and 0973 is only the grading scale (A*–G vs. 9–1) — the content is identical, so 0654 past papers work perfectly for 0973 students. To confirm your code, check your textbook cover, ask your teacher for your Statement of Entry, or look at the top of any past paper your school has given you.
I know my syllabus code — but how do I make sure I'm using the right past papers at the right difficulty level?
You also need to know whether you are entered for Core or Extended. This determines which papers you sit and the maximum grade you can achieve. Core students take Papers 1, 3 and either Paper 5 or Paper 6, and can achieve grades C to G. Extended students take Papers 2, 4 and either Paper 5 or Paper 6, and can achieve grades A* to E. When practising past papers, Core students should focus only on Core questions, while Extended students should practise both Core and Supplement material. If you're unsure which tier you're entered for, ask your teacher or check your Statement of Entry, which lists the exact papers you are registered to sit.
What do the different variants (Variant 1, Variant 2 and Variant 3) mean in Cambridge IGCSE Co-ordinated Sciences (0654) past papers, and can students use all of them for revision?
In Cambridge IGCSE Co-ordinated Sciences (0654), different variants (for example 0654/21, 0654/22 and 0654/23) are separate versions of the same exam paper used in different time zones around the world to prevent students in earlier exam sessions from sharing questions with those sitting the exam later. Each variant tests the same syllabus content, skills and difficulty level, but the questions themselves are different.
For revision purposes, students can and should use all variants (Variant 1, 2 and 3) because they are equally valid practice papers and follow the same exam format and marking standards. Practising multiple variants is actually beneficial as it exposes students to a wider range of exam-style questions that could appear in the real exam.