Cambridge IGCSE Co-ordinated Sciences 0654/22 is the May/June 2026 Paper 2 (Extended Multiple Choice), variant 2. It has 40 questions worth one mark each, lasts 45 minutes and is sat by every Extended candidate. Questions 1 to 13 were biology, 14 to 27 chemistry and 28 to 40 physics. Four questions needed a calculation, from moles of gas to the mass of copper found by displacement, and many more depended on reading a graph or diagram correctly. This guide gives the official answer for every question, the topic it tested and the working for each calculation. The paper and its mark scheme are free on the Tutopiya Learning Portal.

For an overview of all six 0654 papers from this series, see IGCSE Co-ordinated Sciences 0654 May/June 2026 past papers: what came up and how it was marked.

0654/22 at a glance

Syllabus area	Questions	Number of questions
Biology: characteristics of living things, cells, molecules and enzymes	1–4	4
Biology: nutrition, transport and defence against disease	5–9	5
Biology: cell division, natural selection and ecology	10–13	4
Chemistry: bonding, structure and moles	14–16	3
Chemistry: electrolysis, energy, physical change and rate	17–20	4
Chemistry: salts and the Periodic Table	21–23	3
Chemistry: metals, the test for water, organic chemistry and chromatography	24–27	4
Physics: motion, forces, density and pressure	28–31	4
Physics: thermal physics	32–33	2
Physics: waves and light	34–36	3
Physics: magnetism and electromagnetism	37–38	2
Physics: nuclear and space physics	39–40	2
Total		40

Each correct answer scores one mark, so the total is 40. The paper gives the weight of 1.0 kg as 9.8 N and prints the Periodic Table at the back.

Answer key and topic for every question

Question	What it tested	Answer
1	Characteristics shown by a plant turning to face light	C
2	Which cell diagram is most flaccid	A
3	Molecule made from glucose	C
4	Why enzyme activity stops at high temperature	B
5	Graph of rate of photosynthesis against light intensity	C
6	Starch digestion by amylase inside partially permeable tubing	D
7	Name and contents of a vessel in a leaf micrograph	D
8	Correct statement about capillaries	B
9	Why antibodies are specific	A
10	Types of cell division in pollen grain formation	B
11	How overuse of antibiotics leads to resistant bacteria	D
12	What raises carbon dioxide in a sealed bottle garden	B
13	Methods to conserve the Sunda pangolin	A
14	Pair of elements that forms an ionic compound	B
15	Why diamond is used in cutting tools	D
16	Gas sample with the most molecules	C
17	Cathode half-equation in electrolysis of copper(II) sulfate	D
18	Effect of a catalyst on a reaction pathway diagram	A
19	Which process is a physical change	C
20	Rate and volume of gas with half the volume of acid	A
21	Correct statement about preparing and purifying salts	A
22	Trends in melting point and density down Group I	B
23	Correct statement about the halogens	B
24	Reduction in the blast furnace	C
25	Chemical test for water	D
26	Products of complete combustion of ethanol	C
27	Interpreting a paper chromatogram	D
28	Speed-time graph for free fall with no air resistance	D
29	Mass of copper from displacement and density	C
30	Weight from a spring’s load-extension graph	B
31	Pressure when force doubles and area halves	D
32	Why gas pressure rises when the gas is compressed	D
33	Atoms and delocalised electrons in thermal conduction	C
34	Frequency and wavelength after refraction	D
35	Wavelength and gap width for greatest diffraction	C
36	Angle that explains total internal reflection	B
37	Induced magnetism in an iron bar	A
38	Secondary coil of a step-down transformer	D
39	Safe storage of a gamma source	B
40	Which object is a minor planet	C

What the paper tested, topic by topic

Biology (Questions 1–13)

• Characteristics of living things (Question 1): a plant turning its leaves towards light shows movement (a change of position) and sensitivity (detecting a stimulus). Turning towards the light is not a permanent increase in size and dry mass, so the answer is 2 and 3.
• Water and cells (Question 2): the most flaccid cell is the one that has lost the most water, with its contents shrunk furthest away from the cell wall (diagram A).
• Molecules and enzymes (Questions 3 and 4): glycogen is built from glucose. At high temperatures the enzyme’s active site changes shape, so the substrate can no longer fit. Option A swaps in “product” for “substrate”, and options C and D talk about collisions instead of the active site.
• Photosynthesis (Question 5): as light intensity increases, the rate rises and then levels off when another factor limits it. Graph C shows this. The rate does not fall back down at high light intensity, which rules out A and B.
• Digestion (Question 6): amylase breaks starch down chemically into a soluble sugar. The sugar molecules are small enough to pass through the partially permeable tubing, which is why reducing sugar turns up in the water outside as well as inside.
• Transport (Questions 7 and 8): structure Y in the leaf micrograph is xylem, which carries water. Capillary walls are one cell thick, giving a short diffusion distance. Capillaries do not join arteries to the heart, have no muscle to pump blood and have no valves.
• Antibodies (Question 9): an antibody has a region with a shape complementary to one antigen. “Active site” belongs to enzymes, and the antibody and antigen are not the same shape.
• Cell division (Question 10): at stage P a diploid nucleus gives haploid nuclei, which is meiosis. At stage Q a haploid nucleus gives two genetically identical haploid nuclei, which is mitosis.
• Antibiotic resistance (Question 11): antibiotics kill the non-resistant bacteria, leaving the resistant ones with less competition for resources. Bacteria do not become “immune”, and antibiotics do not cause the mutation.
• Carbon cycle (Question 12): decomposition and respiration both release carbon dioxide, so these two raise the concentration in the bottle. Photosynthesis removes carbon dioxide.
• Conservation (Question 13): captive breeding, educating people and protecting the habitat all help conserve the pangolin, so the row with all three ticked is correct.

Chemistry (Questions 14–27)

• Bonding and structure (Questions 14 and 15): fluorine (a non-metal) and potassium (a metal) form an ionic compound; the other pairs are all non-metals. Diamond is used for cutting because its carbon atoms are held together by strong covalent bonds. Options A and B are true statements about diamond, but they do not explain the hardness, and C describes graphite.
• Moles (Question 16): number of moles = mass ÷ Mr. H₂: 2 ÷ 2 = 1 mol. O₂: 48 ÷ 32 = 1.5 mol. N₂: 56 ÷ 28 = 2 mol. SO₂: 64 ÷ 64 = 1 mol. The sample with the most moles has the most molecules, so the answer is nitrogen.
• Electrolysis (Question 17): copper(II) ions gain electrons at the cathode: Cu²⁺ + 2e⁻ → Cu. Option C is the reverse reaction, and B is an anode reaction.
• Catalysts (Question 18): on the diagram, energy change 1 runs from the reactants up to the peak, so it is the activation energy. A catalyst lowers it. Changes 3 and 4 show the overall energy change between reactants and products, which a catalyst does not alter.
• Physical change (Question 19): molecules of a substance moving apart, as in melting or boiling, is physical. Joining molecules, polymerisation and thermal decomposition all make new substances.
• Rate and amount (Question 20): the acid has the same concentration, so the initial rate is the same. The sodium carbonate is in excess, so the acid limits the amount of gas: half the volume of acid gives a lower volume of carbon dioxide.
• Salts (Question 21): crystals of a pure salt form when a hot saturated solution cools. Heating copper(II) sulfate solution to dryness would not give the hydrated crystals, and fractional distillation does not separate salts.
• Groups (Questions 22 and 23): going down Group I, melting point decreases and density increases. Bromine is more reactive than iodine, so it displaces iodine from sodium iodide. Option A has it the wrong way round, because iodine is less reactive than chlorine.
• Blast furnace (Question 24): iron(III) oxide, Fe₂O₃, is reduced to iron.
• Tests and combustion (Questions 25 and 26): anhydrous copper(II) sulfate turns from white to blue with water. (Anhydrous cobalt(II) chloride goes from blue to pink, so options A and B have the colour change reversed or wrong.) Complete combustion of ethanol gives carbon dioxide and water only; carbon monoxide comes from incomplete combustion.
• Chromatography (Question 27): W shows three spots. One matches the single spot of U, and the other two match the two spots of Y, so W is a mixture of U and Y. Y and W are not the same substance, because W has an extra spot.

Physics (Questions 28–40)

• Free fall (Question 28): with no air resistance, the acceleration is constant, so speed rises in a straight line from zero (graph D).
• Density (Question 29): the water level rises from 54 cm³ to 66 cm³, so the copper’s volume is 12 cm³. Mass = density × volume = 8.9 × 12 = 106.8 g, so 107 g. Dividing 12 by 8.9 gives the 1.35 g distractor.
• Springs (Question 30): the extension is 9.0 − 4.0 = 5.0 cm. Reading the graph at 5.0 cm gives a load of 2.0 N. Reading it at the spring’s length (9.0 cm) gives 3.6 N, and at its unstretched length (4.0 cm) gives 1.6 N.
• Pressure (Question 31): p = F ÷ A, so (2.0F) ÷ (0.50A) = 4.0 × F ÷ A = 4.0p.
• Thermal physics (Questions 32 and 33): at constant temperature the particles keep the same speed, but in a smaller volume they hit the walls more often, so the pressure rises. In a metal, the atoms vibrate about fixed positions while the delocalised electrons move throughout the metal and carry energy.
• Refraction (Question 34): frequency never changes when a wave crosses a boundary. The wave bends away from the normal as it enters medium 2, so it speeds up and its wavelength increases.
• Diffraction (Question 35): diffraction is greatest when the gap width is about the same as the wavelength, so λ = 2.0 cm with w = 2.0 cm.
• Total internal reflection (Question 36): angle i is measured from the normal, and the ray is totally reflected because i is greater than the critical angle. Angle h is measured from the surface, so it is the wrong angle to compare.
• Magnetism (Questions 37 and 38): the iron bar faces the magnet’s south pole, so it becomes an induced magnet with a north pole at that end and is attracted (diagram A). Induced magnetism always gives attraction, which rules out C and D. In the step-down transformer, the secondary is the output coil with fewer turns, labelled D.
• Nuclear and space (Questions 39 and 40): a box lined with lead absorbs gamma radiation. Pluto is a minor planet; Mercury, Neptune and Uranus are planets.

Where the marks are on 0654/22

• Chemistry carried 14 marks, and biology and physics 13 each. The sciences come in a fixed order, so you can split your score by science straight from the answer sheet.
• Four questions needed a calculation: 16, 29, 30 and 31. Three of the four were physics. Questions 29 and 30 had distractors built from slips: dividing instead of multiplying, and using the spring’s length instead of its extension.
• Eight questions turned on reading a graph or diagram: the cells (2), the photosynthesis graphs (5), the energy diagram (18), the chromatogram (27), the speed-time graphs (28), the measuring cylinders (29), the load-extension graph (30) and the transformer (38). The refraction (34) and total internal reflection (36) diagrams also had to be read carefully.
• Several questions asked for an explanation, not a fact (Questions 4, 9, 11, 15 and 32). For these, a wrong option can be a true statement that does not answer “why”, as in Question 15.

How to self-mark 0654/22

1. Check each answer against the key above or the official mark scheme. Count one mark per correct letter.
2. Split your score by science: Questions 1–13 biology, 14–27 chemistry, 28–40 physics.
3. Tag every wrong answer by reason: knowledge (for example, the colour change of anhydrous copper(II) sulfate), misread (missing “most” in Question 16 or “no air resistance” in Question 28) or calculation (using 9.0 cm instead of the extension in Question 30, or dividing in Question 29).
4. Redo every calculation you got wrong with the equation written first, then the substitution, then the answer with its unit.
5. For the explanation questions, write one sentence of your own saying why before you look at the options again. This shows whether the gap is knowledge or reading the options.

Sit 0654/22 as a timed mock

You have 45 minutes for 40 questions, a little over one minute each. Answer the recall questions first, mark the ones that need working or a careful diagram read, then come back to them.

Block	Questions	Time
Biology	1–13	12 minutes
Chemistry	14–27	14 minutes
Physics	28–40	14 minutes
Second pass and check the answer sheet	–	5 minutes

Physics gets the most time per question because three of its calculations (29, 30 and 31) and several of its diagrams fall in that block.

Other May/June 2026 0654 papers

• 0654 Paper 12 (Core Multiple Choice)
• 0654 Paper 32 (Core Theory)
• 0654 Paper 42 (Extended Theory)
• 0654 Paper 52 (Practical Test)
• 0654 Paper 62 (Alternative to Practical)

Practise and download

• Download 0654/22 and its mark scheme on the Learning Portal →
• All 0654 May/June 2026 papers: overview and marking patterns
• Try a free IGCSE Co-ordinated Sciences quiz

Need help with a 0654 topic? Book a free trial lesson with an IGCSE Co-ordinated Sciences tutor →

Frequently asked questions

How was 0654 Paper 22 May/June 2026 split between the sciences? +

Questions 1 to 13 were biology, 14 to 27 chemistry and 28 to 40 physics. That is 13 biology marks, 14 chemistry marks and 13 physics marks out of 40.

How many marks is 0654/22 and how long is it? +

It has 40 multiple choice questions, and each correct answer scores one mark, for a total of 40 marks. You have 45 minutes and you may use a calculator.

Is 0654/22 the Core or Extended paper? +

Extended. Paper 2 is the Extended multiple choice paper, sat alongside Paper 4 (Extended Theory) and either Paper 5 or Paper 6. Core candidates sit Paper 1 instead.

What was the answer to the density question on 0654/22? +

C, 107 g. The water level in the measuring cylinder rose by 12 cm³ when the copper went in, so mass = density × volume = 8.9 × 12 = 106.8 g, which rounds to 107 g.

How many questions on 0654/22 2026 needed a calculation? +

Four: Question 16 (moles of gas), Question 29 (mass from density and displacement), Question 30 (weight from a load-extension graph) and Question 31 (pressure when force and area change).

Where can I download 0654/22 May/June 2026 and its mark scheme? +

Both are free to download and print on the Tutopiya Learning Portal, on the Cambridge IGCSE Co-ordinated Sciences 0654 past papers page.

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