IGCSE Sciences - Co-Ordinated (0973) — May–June 2025, Paper 21
40 questions · every question answerable online with instant point-by-point AI marking against the official mark scheme.
Start with Question 1 →Which result with the biuret test shows that protein is present? A blue B green C orange D purple
Answer this question and get it marked →Which term describes the removal of waste products? A excretion B growth C metabolism D mitosis
Answer this question and get it marked →Which type of molecule are enzymes? A carbohydrate B DNA C fat D protein
Answer this question and get it marked →Which substance is essential to make chlorophyll? A calcium ions B cellulose C iron ions D magnesium ions
Answer this question and get it marked →The table shows the energy demand of males and females of different ages. age range energy demand / kJ per person per day (males) energy demand / kJ per person per day (females)…
Answer this question and get it marked →Which organ produces an alkaline mixture that neutralises gastric juices? A salivary glands B large intestine C liver D stomach
Answer this question and get it marked →Which row about translocation is correct? substances transported source sink --- --- --- --- A amino acids and glucose region of production region of use B amino acids and glucose…
Answer this question and get it marked →Yogurt is a food made by adding bacteria to milk. The bacteria feed on sugars in the milk and produce lactic acid. The lactic acid denatures the milk protein. Which process…
Answer this question and get it marked →What is secreted by the pancreas? A glucagon B glucose C glycerol D glycogen
Answer this question and get it marked →The diagram shows a flower. A structure labelled P is indicated by a line pointing to long, feathery, thread-like structures hanging below the petals (the stamens, with feathery…
Answer this question and get it marked →Polydactyly is the possession of additional fingers or toes. It is caused by a dominant allele. The pedigree diagram shows the inheritance of polydactyly by a family. The key…
Answer this question and get it marked →In the food chain shown, 10% of the energy is transferred between each trophic level. grass - grasshopper - frog - snake - buzzard How much energy is transferred to the tertiary…
Answer this question and get it marked →The table shows the dates that different antibiotics were introduced and the dates that antibiotic-resistant bacteria were first reported. antibiotic date introduced date…
Answer this question and get it marked →Which graph shows the temperature change when an impure, solid substance is heated? Four temperature against time graphs are shown. A: temperature rises, then a short sloping (not…
Answer this question and get it marked →Information about four gases is shown. gas molecular formula --- --- ammonia NH3 butane C4H10 carbon dioxide CO2 chlorine Cl2 Which gas has the greatest rate of diffusion? A…
Answer this question and get it marked →The electronic configurations of four particles are shown. Each is drawn as a nucleus surrounded by shells of crosses representing electrons. The four diagrams (1-4) show…
Answer this question and get it marked →An aluminium atom forms an aluminium ion, Al3+. Which statement describes what happens to the aluminium atom? A It gains 3 electrons. B It gains 3 protons. C It loses 3 electrons.…
Answer this question and get it marked →What is the balanced equation for the combustion of hydrogen? A 2H + O - H2O B H2 + O2 - H2O C H2 + O - H2O D 2H2 + O2 - 2H2O
Answer this question and get it marked →Which description of mass is used to define relative atomic mass, Ar? A the mass of 1/12 of a mole of 12C atoms B the mass of one mole of 12C atoms C the mass of 1/12 the mass of…
Answer this question and get it marked →Which quantities, when measured at room temperature and pressure, contain one mole of oxygen molecules? 1 16 g of oxygen molecules 2 12 dm3 of oxygen molecules 3 the Avogadro…
Answer this question and get it marked →Which gas is formed at the cathode during electrolysis? A carbon dioxide B chlorine C hydrogen D oxygen
Answer this question and get it marked →A reaction pathway diagram for a reaction is shown. On axes of energy / (kJ/mol) against progress of reaction, the reactants are at an energy of 100 kJ/mol, the curve rises to a…
Answer this question and get it marked →Compounds are made up from two or more different elements ......1...... bonded together. Compounds cannot be broken down into simpler substances by ......2...... processes.…
Answer this question and get it marked →Which statement describes an amphoteric oxide? A It does not react with either sodium hydroxide or hydrochloric acid. B It reacts with sodium hydroxide but not hydrochloric acid.…
Answer this question and get it marked →Which diagram represents the structure of an alloy? Four diagrams of particle arrangements are shown. A: a regular close-packed arrangement of mostly same-size circles with a few…
Answer this question and get it marked →The structure of compound P is shown. It is a chain of four carbon atoms, each fully bonded to hydrogen atoms, with the end carbon bonded to an -O-H (hydroxyl) group:…
Answer this question and get it marked →The chromatogram of four substances is shown. The baseline is at 0 cm and the solvent front is at 10 cm. The spots are at: A at 5 cm, B at 2.5 cm, C at 7.5 cm and D at 9.5 cm…
Answer this question and get it marked →The diagram shows the extension-load graph for a spring. The length of the unloaded spring is 4.0 cm. The graph is a straight line through the origin of extension / cm against…
Answer this question and get it marked →What is the unit of work and what is an equivalent combination of units? unit equivalent combination --- --- --- A joule newton metre B joule newton / metre C newton joule metre D…
Answer this question and get it marked →The total energy input to an electric lamp is 20 J. The useful energy output is 12 J. What is the efficiency of the lamp? A 33% B 40% C 60% D 66%
Answer this question and get it marked →Which statement explains why smoke particles are made to move by other particles in Brownian motion? A The other particles are larger and move faster than smoke particles. B The…
Answer this question and get it marked →Some materials use atomic or molecular lattice vibrations and some materials use the movement of delocalised electrons for thermal conduction. Which row shows the correct…
Answer this question and get it marked →Which surface is the best absorber of thermal radiation? A dull black B dull white C shiny black D shiny white
Answer this question and get it marked →The diagram shows a ray of light passing from medium P to medium Q and then to medium R. The speeds of light in each of the mediums P, Q and R are cP, cQ and cR respectively. The…
Answer this question and get it marked →What is the speed of X-rays in a vacuum? A 3.0 x 10^2 m/s B 3.0 x 10^4 m/s C 3.0 x 10^6 m/s D 3.0 x 10^8 m/s
Answer this question and get it marked →An electric kettle is rated at 3.0 kW and is connected to a 250 V supply. The kettle is switched on for 2.0 minutes. Which row shows the current in the kettle and the energy…
Answer this question and get it marked →The diagram shows resistors of resistance R1 and R2 connected in parallel. The combined resistance of the resistors is RT. Currents I1, I2 and I3 are labelled. In the circuit, a…
Answer this question and get it marked →The diagram shows the direction of the current in a wire. The wire is placed between the poles of a magnet and this causes a force to act on the wire. The N pole is on the left…
Answer this question and get it marked →Which statement about background radiation is correct? A All of it comes from the ground. B None of it comes from the air. C Only people who fly long distances are exposed to it.…
Answer this question and get it marked →Planet X and planet Y orbit the Sun and are at different distances from the Sun. The gravitational field strength of the Sun is greater at the position of planet X than it is at…
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