IGCSE Science - Combined (0653) — October–November 2023, Paper 21
40 questions · every question answerable online with instant point-by-point AI marking against the official mark scheme.
Start with Question 1 →The diagram shows a plant absorbing carbon dioxide in order to carry out photosynthesis. carbon dioxide Which characteristic of all living organisms is this? A movement B…
Answer this question and get it marked →Four different cells and functions are shown. Which cell has the correct function stated? A B involved in reproduction moves mucus in the trachea C D involved in photosynthesis…
Answer this question and get it marked →What is diffusion? A net movement of molecules down a concentration gradient B net movement of molecules up a concentration gradient C total movement of molecules down a…
Answer this question and get it marked →Which graph shows the effect of increasing pH on enzyme activity? A B rate of rate of reaction reaction pH pH C D rate of rate of reaction reaction pH pH
Answer this question and get it marked →What is the correct definition of a balanced diet? A a diet in which all the components needed to maintain health are present in appropriate proportions B a diet which contains…
Answer this question and get it marked →The diagram shows what happens to fat in the alimentary canal. enzyme (2) large piece (1) (3) small (4) of fat molecules Which row correctly identifies 1, 2, 3 and 4? 1 2 3 4 A…
Answer this question and get it marked →The diagram shows a section through the heart. X What causes valve X to close? A contraction of the left ventricle B contraction of the left atrium C relaxation of the left…
Answer this question and get it marked →Which chemical is used to test for carbon dioxide in expired air? A Benedict’s solution B distilled water C iodine solution D limewater
Answer this question and get it marked →Six molecules of glucose are aerobically respired in an animal cell. How many molecules of carbon dioxide are released in this process? A 1 B 6 C 12 D 36
Answer this question and get it marked →Which statement about auxin is correct? A Auxin is always equally distributed. B Auxin is made in the carpels only. C Auxin spreads through the plant from the sepals. D Auxin…
Answer this question and get it marked →Which row is correct for sexual reproduction? genetically different one zygote offspring produced parent produced A ✓ ✓ ✗ B ✓ ✗ ✓ C ✗ ✓ ✗ D ✗ ✗ ✓
Answer this question and get it marked →Which feature is a structural adaptation found in wind-pollinated flowers? A Scent is produced. B Nectar is produced. C Petals are small or absent. D Stigma is inside flower.
Answer this question and get it marked →The diagram shows part of the carbon cycle. photosynthesis green Y plants animals combustion X What are X and Y? X Y A fossil fuel carbon dioxide B carbon dioxide oxygen C fossil…
Answer this question and get it marked →Which substance is liquid at 25 °C? melting point boiling point / °C / °C A –182 –161 B –100 80 C –77 –34 D 44 280
Answer this question and get it marked →A solid is added to a liquid and stirred until the solid is no longer visible. Which word describes the type of mixture that is formed? A concentration B solute C solution D…
Answer this question and get it marked →Which dot-and-cross diagram represents the outer shell electrons in a nitrogen molecule? A B N N N N C D N N N N
Answer this question and get it marked →Iron(III) sulfate contains Fe3+ ions and SO42– ions. What is the formula of iron(III) sulfate? A FeSO4 B Fe3SO4 C Fe2(SO4)3 D Fe3(SO4)2
Answer this question and get it marked →During electrolysis, positive ions are changed. Which row describes what happens to the positive ions and identifies the electrode where this happens? what happens to electrode…
Answer this question and get it marked →Dilute hydrochloric acid and calcium carbonate react together to produce a gas. The rate of reaction changes if the concentration of the hydrochloric acid or the temperature is…
Answer this question and get it marked →The equation for the redox reaction between aluminium and iron(III) oxide is shown. 2Al + Fe2O3 → 2Fe + Al 2O3 Which row identifies the substance that is reduced and the oxidising…
Answer this question and get it marked →Calcium oxide is added to water containing universal indicator. The universal indicator turns blue. What is the pH of the solution? A 1 B 6 C 7 D 11
Answer this question and get it marked →Acid X reacts with metal Y. A colourless gas is given off and a pale green solution is produced. Two tests are carried out on the solution. test reagents added result 1 aqueous…
Answer this question and get it marked →Fluorine is at the top of Group VII in the Periodic Table. It reacts with potassium iodide as shown. fluorine + potassium iodide → iodine + substance Z What is substance Z? A…
Answer this question and get it marked →Which statements about metals and their compounds are correct? 1 Copper reacts with dilute hydrochloric acid to give hydrogen. 2 Carbon does not react with aluminium oxide. 3…
Answer this question and get it marked →Different reactions occur in the blast furnace. Which substances are products in some reactions and reactants in other reactions in the blast furnace? A carbon dioxide and carbon…
Answer this question and get it marked →Which gases can directly cause an enhanced greenhouse effect? A carbon monoxide and carbon dioxide B carbon dioxide and methane C nitrogen dioxide and sulfur dioxide D sulfur…
Answer this question and get it marked →Which statement about alkanes is correct? A Their molecules are unsaturated. B They are generally reactive compounds. C They are mixtures of carbon and hydrogen atoms only. D They…
Answer this question and get it marked →Which speed–time graph represents motion for which the acceleration is constant but not zero? A B speed speed 0 0 0 time 0 time C D speed speed 0 0 0 time 0 time
Answer this question and get it marked →A glass block has a mass of 30 g and a volume of 15 cm3. What is the density of the glass? A 0.50 g / cm3 B 2.0 g / cm3 C 15 g / cm3 D 450 g / cm3
Answer this question and get it marked →A spring that obeys Hooke’s law is stretched by a force of 4.0 N. The length of the spring changes from 10 cm to 12 cm. What is the spring constant of the spring? A 0.33 N / cm B…
Answer this question and get it marked →A car has a kinetic energy of 200 kJ as it passes a point P on a straight horizontal road. A constant resultant force of 500 N then causes the car to accelerate. What is the…
Answer this question and get it marked →A man lifts a heavy load vertically, from the ground to above his head. load He then moves the load horizontally at constant speed. During which motion is work done on the load,…
Answer this question and get it marked →Which statement about a tidal energy power station is correct? A It creates no environmental impact when being built. B It does not work at night. C It does not work when there is…
Answer this question and get it marked →The molecules in a substance are close together but free to change positions with each other. Which substance at 20 °C matches this description? A air B copper C iron D water
Answer this question and get it marked →A sound wave passes from one medium into a second medium. What happens to the sound wave entering the second medium and why does this happen? what happens why it happens A it is…
Answer this question and get it marked →An earthquake wave shakes the ground at right angles to the direction of travel of the wave. This wave has a frequency of 0.10 Hz and a wavelength of 30 000 m. Which row shows the…
Answer this question and get it marked →The diagram shows two light rays from an object that pass through a thin converging lens. Each point labelled F is a principal focus of the lens. lens object F F What is the…
Answer this question and get it marked →The amplitude of a sound wave decreases and its frequency increases. What happens to the sound heard? A It becomes louder and its pitch becomes higher. B It becomes louder and its…
Answer this question and get it marked →There is a current of 6.0 A in a wire. How much charge flows through the wire in 2.0 minutes? A 0.050 C B 3.0 C C 12 C D 720 C
Answer this question and get it marked →A circuit contains three ammeters, P, Q and R, and three identical lamps. P A Q A R A How do the readings on the ammeters compare? A All three ammeters show the same reading. B…
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