Cambridge IGCSE Science - Combined 0653 — 2021 May/June Paper 1 · Variant 3
0653/13/M/J/21 · 40 questions · 40 marks · ≈45 min
The question paper and its mark scheme, free to read here and free to download. This is Cambridge’s own paper, exactly as it was sat.
Question paper20 pages
Mark scheme3 pages
Answers below. Sit the paper first if you are practising.
Questions as text
Q1 · The diagrams represent four similar animal cells immersed in blood plasma
1 The diagrams represent four similar animal cells immersed in blood plasma. The black dots represent molecules of dissolved oxygen. Which cell will have oxygen molecules diffusing into it most rapidly? A B C D
Mark scheme: C
Q2 · The table shows the results of some food tests carried out on one sample of food
2 The table shows the results of some food tests carried out on one sample of food. colour at start colour at end food test reagent of test of test Benedict’s solution blue blue biuret reagent blue purple iodine solution brown blue / black Which nutrients does the food sample contain? A protein and starch B protein and reducing sugar C starch only D starch and reducing sugar
Mark scheme: A
Q3 · Which row describes an enzyme?
3 Which row describes an enzyme? type of molecule function A carbohydrate speeds up a reaction and is used up in the process B carbohydrate speeds up a reaction and is not used up in the process C protein speeds up a reaction and is used up in the process D protein speeds up a reaction and is not used up in the process
Mark scheme: D
Q4 · The flow diagram shows the stages in testing a green leaf for starch
4 The flow diagram shows the stages in testing a green leaf for starch. 1, 2, 3 and 4 are all liquids. 4 iodine solution white tile hot water 1 2 3 boiling water boiling alcohol to warm water to kill the leaf remove the chlorophyll to wash the leaf What are the colours of liquids 2 and 4 for a leaf that contains starch? 2 4 A green blue / black B colourless brown C colourless blue / black D green brown
Mark scheme: A
Q5 · Most food molecules need to be digested to allow them to be absorbed into the blood
5 Most food molecules need to be digested to allow them to be absorbed into the blood. Which row shows the type of digestion and the change needed to allow absorption to happen? type of digestion change to food molecules A chemical large molecules to small, insoluble molecules B chemical large molecules to small, soluble molecules C mechanical large molecules to small, soluble molecules D mechanical large molecules to small, insoluble molecules
Mark scheme: B
Q6 · Which conditions cause the lowest rate of transpiration?
6 Which conditions cause the lowest rate of transpiration? humidity temperature A high high B high low C low high D low low
Mark scheme: B
Q7 · The diagram shows the human gas exchange system
7 The diagram shows the human gas exchange system. X What is the part labelled X? A alveolus B bronchus C larynx D trachea
Mark scheme: D
Q8 · Which equation represents aerobic respiration?
8 Which equation represents aerobic respiration? A carbon dioxide + glucose oxygen + water B carbon dioxide + water glucose + oxygen C glucose + oxygen carbon dioxide + water D glucose + water carbon dioxide + oxygen
Mark scheme: C
Q9 · A plant in a pot was placed on its side for four days
9 A plant in a pot was placed on its side for four days. shoot root start after four days Which row describes the gravitropic response in the root and shoot? root shoot A positive negative B negative positive C negative negative D positive positive
Mark scheme: A
Q10 · During human reproduction an egg fuses with a sperm
10 During human reproduction an egg fuses with a sperm. Sometimes the zygote splits into two and produces twins. Which row describes the formation of these twins? original zygote produced by twins A asexual reproduction genetically identical B sexual reproduction genetically identical C asexual reproduction genetically different D sexual reproduction genetically different
Mark scheme: B
Q11 · Which diagram of the female reproductive system is correctly labelled?
11 Which diagram of the female reproductive system is correctly labelled? A B ovary ovary cervix vagina vagina cervix C D cervix cervix ovary vagina vagina ovary
Mark scheme: B
Q12 · The diagram shows a food web
12 The diagram shows a food web. fox toad stoat rabbit spider vole insect plant fruits and leaves Which two organisms are both secondary consumers? A insect and spider B insect and toad C rabbit and stoat D spider and toad
Mark scheme: D
Q13 · Which process takes carbon dioxide out of the air?
13 Which process takes carbon dioxide out of the air? A combustion B decomposition C photosynthesis D plant respiration
Mark scheme: C
Q14 · The melting point and boiling point of oxygen and nitrogen are shown
14 The melting point and boiling point of oxygen and nitrogen are shown. melting point boiling point / C / C oxygen –219 –183 nitrogen –210 –196 A sealed flask contains a mixture of oxygen and nitrogen. Which diagram shows the arrangement of oxygen and nitrogen particles at –190 C? A B C D key = nitrogen molecules = oxygen molecules
Mark scheme: A
Q15 · What is an example of a physical change?
15 What is an example of a physical change? A carbon dioxide turning limewater milky B the crystallisation of copper(II) sulfate from solution C the electrolysis of molten lead(II) bromide D the thermal decomposition of calcium carbonate
Mark scheme: B
Q16 · Water has the chemical formula H2O
16 Water has the chemical formula H2O. Which statement is correct? A Pure water is a mixture because it contains hydrogen and oxygen. B Pure water is an element because it contains only one type of molecule. C Salt water is a compound because it contains salt and water. D Salt water is a mixture because it contains salt and water.
Mark scheme: D
Q17 · What are the products of the electrolysis of concentrated aqueous sodium chloride using…
17 What are the products of the electrolysis of concentrated aqueous sodium chloride using inert electrodes? anode cathode A chlorine hydrogen B chlorine sodium C oxygen hydrogen D oxygen sodium
Mark scheme: A
Q18 · Some calcium carbonate and dilute hydrochloric acid start to react
18 Some calcium carbonate and dilute hydrochloric acid start to react. Water is then added to the reaction mixture. What happens to the rate of the reaction? A It decreases. B It increases. C It stays the same. D It stops.
Mark scheme: A
Q19 · In six separate experiments, dilute sulfuric acid is added separately to the substances…
19 In six separate experiments, dilute sulfuric acid is added separately to the substances listed. ● magnesium ● magnesium oxide ● magnesium carbonate ● copper ● copper oxide ● copper carbonate How many of these experiments produce a gas? A 2 B 3 C 4 D 5
Mark scheme: B
More questions on The characteristic properties of acids and bases
Q20 · Which two substances form a white precipitate when they are mixed?
20 Which two substances form a white precipitate when they are mixed? A barium chloride and hydrochloric acid B barium chloride and nitric acid C silver nitrate and hydrochloric acid D silver nitrate and nitric acid
Mark scheme: C
Q21 · How does the character of the elements change across a period of the Periodic Table from…
21 How does the character of the elements change across a period of the Periodic Table from left to right? A acidic to basic B basic to acidic C metallic to non-metallic D non-metallic to metallic
Mark scheme: C
Q22 · Ruthenium is a transition element
22 Ruthenium is a transition element. Which row describes ruthenium? forms coloured can be used as compounds a catalyst A x x B x v Cc v x D Jv v key /=yes X=n0o
Mark scheme: D
Q23 · Which words describe a noble gas?
23 Which words describe a noble gas? A compound, colourless, does not burn in air B element, colourless, burns in air C element, colourless, does not burn in air D element, green, does not burn in air
Mark scheme: C
Q24 · A steam boiler is a container in which water is converted into steam
24 A steam boiler is a container in which water is converted into steam. The steam is used to turn turbines which generate electricity. Which metal can be used to make a steam boiler? A calcium B copper C magnesium D zinc
Mark scheme: B
Q25 · An experiment is set up to investigate the rusting of iron nails
25 An experiment is set up to investigate the rusting of iron nails. In which test-tube does the iron nail not rust because a barrier method of rust prevention is used? A B C D bung oil air boiled water water water iron nail iron nail iron nail painted drying iron nail agent
Mark scheme: D
Q26 · Which type of compound contains only carbon and hydrogen?
26 Which type of compound contains only carbon and hydrogen? A carbohydrate B carbonate C hydrocarbon D hydroxide
Mark scheme: C
Q27 · Which substance turns aqueous bromine colourless?
27 Which substance turns aqueous bromine colourless? A an alkane B an alkene C a saturated hydrocarbon D poly(ethene)
Mark scheme: B
Q28 · Which speed–time graph represents an object that is moving with constant speed?
28 Which speed–time graph represents an object that is moving with constant speed? A B speed speed 0 0 0 time 0 time C D speed speed 0 0 0 time 0 time
Mark scheme: D
Q29 · The diagrams show four solid blocks that each have a mass of 15 800 kg
29 The diagrams show four solid blocks that each have a mass of 15 800 kg. The dimensions of each block are shown. Iron has a density of 7900 kg / m3. Which block is made of iron? A B 0.50 m 1.0 m 0.50 m 1.0 m 1.0 m 2.5 m C D 1.0 m 0.20 m 2.0 m 1.0 m 2.0 m 1.0 m
Mark scheme: C
Q30 · Which change cannot be caused by a force acting on an object?
30 Which change cannot be caused by a force acting on an object? A change of mass B change of motion C change of shape D change of size
Mark scheme: A
Q31 · An object is lifted vertically upwards
31 An object is lifted vertically upwards. Which change results in the same quantity of work being done? A lifting a heavier object through a greater distance in the same time B lifting a lighter object through the same distance in a smaller time C lifting the same object through a greater distance in the same time D lifting the same object through the same distance in a greater time
Mark scheme: D
Q32 · Which source of energy is non-renewable?
32 Which source of energy is non-renewable? A chemical energy stored in fossil fuels B energy stored in waves C energy stored in water behind a hydroelectric dam D wind energy
Mark scheme: A
Q33 · Cold water evaporates as molecules leave it
33 Cold water evaporates as molecules leave it. Which molecules leave the water and from which part of the water do they leave? molecules that where they leave the water leave from A least energetic the surface only B least energetic throughout the water C most energetic the surface only D most energetic throughout the water
Mark scheme: C
Q34 · Energy is transferred from the Sun to the Earth through the vacuum of space
34 Energy is transferred from the Sun to the Earth through the vacuum of space. Which method of energy transfer is involved? A conduction B convection C evaporation D radiation
Mark scheme: D
Q35 · A navigation buoy floating on the sea oscillates up and down as a wave passes
35 A navigation buoy floating on the sea oscillates up and down as a wave passes. navigation buoy sea In 2.0 minutes, 6.0 wavelengths pass the buoy. What is the frequency of the waves? A 0.050 Hz B 0.33 Hz C 3.0 Hz D 20 Hz
Mark scheme: A
Q36 · Which diagram shows how a converging lens forms a real image at the point labelled I?
36 Which diagram shows how a converging lens forms a real image at the point labelled I? A B I I C D I I
Mark scheme: B
Q37 · There is a current in a solid metal wire
37 There is a current in a solid metal wire. Which particles flow through the wire, and which instrument is used to measure a current? particles instrument A electrons ammeter B electrons voltmeter C ions ammeter D ions voltmeter
Mark scheme: A
Q38 · The diagram represents a circuit that includes a battery, an ammeter, a voltmeter and a…
38 The diagram represents a circuit that includes a battery, an ammeter, a voltmeter and a variable resistor. A V What happens to the readings on the meters as the resistance of the variable resistor is increased? ammeter reading voltmeter reading A decreases decreases B decreases stays constant C increases decreases D increases stays constant
Mark scheme: B
Q39 · A 20 resistor and a 15 resistor are connected in parallel
39 A 20 resistor and a 15 resistor are connected in parallel. 20 Ω 15 Ω What is the combined resistance of the two resistors? A less than 15 B between 15 and 20 C 35 D greater than 35
Mark scheme: A
Q40 · An air conditioner and a television are both connected to the same electrical circuit
40 An air conditioner and a television are both connected to the same electrical circuit. X power air television supply conditioner The current in the air conditioner is 9.0 A and the current in the television is 2.0 A. Several different fuses are available. Which fuse should be connected at X? A 1 A B 3 A C 7 A D 13 A
Mark scheme: D
What was in this paper
The subtopics covered by these 40 questions, and how many questions each got. Open one in a new tab to see every Cambridge question on it.
2Energy, work and power2Sexual reproduction in humans2Alkenes1Arrangement of elements1Biological molecules1Carbon cycle1Characteristics of living organisms1Corrosion of metals1Density1Diffusion1Digestion1Electrical quantities1Electrical safety1Electrolysis1Elements, compounds and mixtures1Enzymes1Food chains and food webs1Forces1Gas exchange in humans1General properties of waves1Identification of ions and gases1Kinetic particle model of matter1Light1Motion1Noble gases1Photosynthesis1Physical and chemical changes1Rate of reaction1Respiration1Solids, liquids and gases1Terminology1The characteristic properties of acids and bases1Transfer of thermal energy1Transition elements1Transpiration1Uses of metals1What you needed in this session
Cambridge’s own grade thresholds for 2021 May/June, Paper 1 · Variant 3. A higher threshold means an easier paper — the bar moves with how the cohort did.