Cambridge IGCSE Science - Combined 0653 — 2020 Oct/Nov Paper 2 · Variant 1
0653/21/O/N/20 · 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 paper16 pages
Mark scheme3 pages
Answers below. Sit the paper first if you are practising.
Questions as text
Q1 · The diagram shows a cell
1 The diagram shows a cell. X What is the function of X? A contains the genetic information B controls substances entering and leaving the cell C maintains the shape of the cell D photosynthesis
Mark scheme: C
Q2 · What is the function of ciliated cells in the bronchi?
2 What is the function of ciliated cells in the bronchi? A absorption of oxygen B movement of mucus C production of mucus D transport of oxygen
Mark scheme: B
Q3 · The diagram shows how the activity of an enzyme changes with temperature
3 The diagram shows how the activity of an enzyme changes with temperature. enzyme activity / arbitrary units X temperature / °C This enzyme works in the human body. What is the most likely value of temperature X? A 10 C B 40 C C 70 C D 100 C
Mark scheme: B
Q4 · What is necessary for photosynthesis?
4 What is necessary for photosynthesis? 1 carbon dioxide 2 chlorophyll 3 glucose 4 light 5 oxygen 6 water A 1, 2, 4 and 6 B 1, 3, 4 and 6 C 2, 3, 4 and 5 D 3, 4, 5 and 6
Mark scheme: A
Q5 · Deficiencies in vitamin D and in iron can cause diseases
5 Deficiencies in vitamin D and in iron can cause diseases. Which statement is correct? A Vitamin D deficiency can cause anaemia. B Vitamin D deficiency can cause rickets. C Iron deficiency can cause rickets. D Iron deficiency can cause scurvy.
Mark scheme: B
Q6 · Which enzymes are secreted from the pancreas?
6 Which enzymes are secreted from the pancreas? 1 amylase 2 lipase 3 protease A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3
Mark scheme: D
Q7 · The graph shows the uptake of water by root hair cells over many hours during a day
7 The graph shows the uptake of water by root hair cells over many hours during a day. T water uptake by root hair cells 0 0 time What could have caused the change in the rate of uptake at T? A decrease in temperature B decrease in humidity C increase in light intensity D increase in temperature
Mark scheme: A
Q8 · How does mucus benefit the gas exchange system?
8 How does mucus benefit the gas exchange system? A It absorbs carbon monoxide before it reaches the alveoli. B It prevents friction between the air and the trachea. C It removes the nicotine in cigarette smoke. D It traps pathogens.
Mark scheme: D
Q9 · Which statement about adrenaline is correct?
9 Which statement about adrenaline is correct? A It is produced by a gland. B It is transported in the red blood cells. C It only has one target organ. D It reduces the size of the pupils.
Mark scheme: A
Q10 · Which row shows the correct descriptions for the anther and stigma of a wind-pollinated…
10 Which row shows the correct descriptions for the anther and stigma of a wind-pollinated flower? anther stigma stigma position position description A inside flower inside flower smooth B exposed exposed feathery C exposed inside flower smooth D inside flower exposed feathery
Mark scheme: B
Q11 · Which row describes asexual reproduction?
11 Which row describes asexual reproduction? number of a zygote is offspring identical parents produced to the parent A 1 no yes B 1 yes no C 2 no yes D 2 yes no
Mark scheme: A
Q12 · The diagram shows a placenta and umbilical cord
12 The diagram shows a placenta and umbilical cord. X key umbilical artery X movement of oxygen from fetus to fetus X mother’s umbilical blood vein X Which row is correct? high oxygen low oxygen name of concentration concentration process X present present A umbilical artery umbilical vein diffusion B umbilical artery umbilical vein osmosis C umbilical vein umbilical artery diffusion D umbilical vein umbilical artery osmosis
Mark scheme: C
Q13 · Eutrophication results in the death of aquatic organisms
13 Eutrophication results in the death of aquatic organisms. What is a stage in this process? A reduced aerobic respiration by decomposers B reduced decomposition after death of producers C reduced growth of producers D reduced levels of dissolved oxygen
Mark scheme: D
Q14 · Which term describes ammonia, NH3?
14 Which term describes ammonia, NH3? A element B ion C atom D molecule
Mark scheme: D
Q15 · Two different dyes are analysed using chromatography
15 Two different dyes are analysed using chromatography. Each dye produces only one coloured spot on the chromatogram. The Rf values of the coloured spots are shown. coloured Rf value spot red 0.2 blue 0.4 The two different dyes are then mixed together to make a purple dye. What is observed on the chromatogram of the purple dye? A one spot with Rf value 0.3 B one spot with Rf value 0.6 C two spots with Rf values 0.2 and 0.4 D three spots with Rf values 0.2, 0.3 and 0.4
Mark scheme: C
Q16 · Which statement describes a mixture?
16 Which statement describes a mixture? A It contains molecules made from the same type of atom. B It contains only one type of atom. C It contains two different types of atom joined by chemical bonds. D It contains two different types of atom that can be separated by physical processes.
Mark scheme: D
Q17 · Aqueous lead(II) nitrate, Pb(NO3)2, reacts with potassium iodide to make a precipitate of…
17 Aqueous lead(II) nitrate, Pb(NO3)2, reacts with potassium iodide to make a precipitate of lead(II) iodide. What is the ionic equation for this reaction? A Pb+ + I– PbI B Pb2+ + 2I– PbI2 C Pb(NO3)2 + I– PbI + 2NO3 – D Pb2+ + 2NO3 – + 2I– PbI2 + 2NO3 –
Mark scheme: B
Q18 · Which statement about the electrolysis of a molten metal halide is correct?
18 Which statement about the electrolysis of a molten metal halide is correct? A Cations move to the anode. B Electrons flow through the electrolyte. C Ions gain protons at the cathode. D Ions lose electrons at the anode.
Mark scheme: D
Q19 · The energy level diagram for an endothermic reaction is shown
19 The energy level diagram for an endothermic reaction is shown. energy progress of reaction Which statement about this reaction is correct? A The activation energy is the energy required to break bonds. B The energy required to break bonds is less than the energy released on making new bonds. C The activation energy is less than the energy change for the reaction. D The final products have less energy than the reactants.
Mark scheme: A
Q20 · Iron can be obtained from iron(III) oxide by heating with aluminium powder
20 Iron can be obtained from iron(III) oxide by heating with aluminium powder. The equation is shown. 2Al + Fe2O3 Al 2O3 + 2Fe What is the oxidising agent? A Al B Fe2O3 C Al 2O3 D Fe
Mark scheme: B
Q21 · Which substances react with dilute sulfuric acid to make copper sulfate?
21 Which substances react with dilute sulfuric acid to make copper sulfate? 1 copper 2 copper carbonate 3 copper hydroxide 4 copper nitrate A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4
Mark scheme: C
Q22 · Acid X reacts with metal Y
22 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 reagent(s) added result 1 aqueous silver nitrate and nitric acid white precipitate 2 aqueous sodium hydroxide green precipitate What are acid X and metal Y? acid metal A hydrochloric iron B hydrochloric zinc C sulfuric iron D sulfuric zinc
Mark scheme: A
Q23 · Rubidium and sodium are elements in Group I of the Periodic Table
23 Rubidium and sodium are elements in Group I of the Periodic Table. The atomic number of sodium is 11, and the atomic number of rubidium is 37. Rubidium has a ……1…… melting point and a ……2…… density than sodium. The reactivity of rubidium is ……3…… than the reactivity of sodium. Which row completes gaps 1, 2 and 3? 1 2 3 A higher lower lower B lower lower higher C lower higher higher D higher higher lower
Mark scheme: C
Q24 · Ammonia, NH3, can be made by combining the gases nitrogen, N2, and hydrogen, H2
24 Ammonia, NH3, can be made by combining the gases nitrogen, N2, and hydrogen, H2. This reaction is slow. When element Y is added, the rate of reaction increases. What is Y? A Al B Fe C Rb D I2
Mark scheme: B
Q25 · Which method is used to extract copper from copper(II) oxide?
25 Which method is used to extract copper from copper(II) oxide? A dissolving copper(II) oxide in hydrochloric acid and then filtering B dissolving copper(II) oxide in water and then filtering C heating the copper(II) oxide D heating the copper(II) oxide mixed with carbon
Mark scheme: D
Q26 · Which statement describes a hydrocarbon?
26 Which statement describes a hydrocarbon? A a compound that burns to form carbon dioxide and hydrogen B a compound that contains carbon and hydrogen only C a compound that only contains ionic bonds D a compound that reacts easily with metals
Mark scheme: B
Q27 · What can be produced when naphtha is cracked?
27 What can be produced when naphtha is cracked? A alkanes, alkenes and hydrogen B alkanes and alkenes only C alkanes and hydrogen only D alkenes only
Mark scheme: A
Q28 · What does the area under a speed–time graph represent?
28 What does the area under a speed–time graph represent? A acceleration B average speed C distance travelled D maximum speed
Mark scheme: C
Q29 · A satellite of mass 20 kg is in orbit around the Earth
29 A satellite of mass 20 kg is in orbit around the Earth. At the height of the satellite’s orbit, the gravitational field strength is one quarter of its strength on the surface of the Earth. The gravitational field strength on the surface of the Earth is 10 N / kg. What is the weight of the satellite as it orbits the Earth? A 0 N B 20 N C 50 N D 200 N
Mark scheme: C
Q30 · A raindrop falls vertically at a constant speed
30 A raindrop falls vertically at a constant speed. What is the resultant force on the raindrop as it falls? A It is equal to the air pressure on the drop. B It is equal to the air resistance on the drop. C It is equal to the weight of the drop. D It is zero.
Mark scheme: D
Q31 · An apple falls to the ground
31 An apple falls to the ground. Which form of energy decreases as the apple falls? A chemical potential B gravitational potential C kinetic D sound
Mark scheme: B
Q32 · A builder drops a brick from a height of 15 m above the ground
32 A builder drops a brick from a height of 15 m above the ground. The gravitational field strength g is 10 N / kg. What is the speed of the brick as it hits the ground? A 12 m / s B 17 m / s C 150 m / s D 300 m / s
Mark scheme: B
Q33 · The molecules in a substance vibrate about fixed positions
33 The molecules in a substance vibrate about fixed positions. The substance is now cooled. Which row gives the state of the substance and the effect of cooling on the distance between its molecules? state of effect on distance substance between molecules A solid decreases B solid increases C liquid decreases D liquid increases
Mark scheme: A
Q34 · In which states of matter can convection occur?
34 In which states of matter can convection occur? in a solid in a liquid in a gas A no no yes B no yes yes C yes no no D yes yes no
Mark scheme: B
Q35 · The diagram shows a section of a rope
35 The diagram shows a section of a rope. Four wave crests pass a point on the rope every second. Each wave crest travels 80 cm in one second. wave crest 20 cm direction 5.0 cm of wave What is the speed of the wave? A 4.0 cm / s B 5.0 cm / s C 20 cm / s D 80 cm / s
Mark scheme: D
Q36 · A converging lens is used as a magnifying glass
36 A converging lens is used as a magnifying glass. Where is the image formed and what is the nature of the image? position of image nature A on the opposite side of the lens to the object real B on the opposite side of the lens to the object virtual C on the same side of the lens as the object real D on the same side of the lens as the object virtual
Mark scheme: D
Q37 · The diagram represents a wave in air
37 The diagram represents a wave in air. Molecules are closer together in region P than they are in region Q. region P region Q What are the names of regions P and Q, and which type of wave is represented? region P region Q type of wave A compression rarefaction longitudinal B compression rarefaction transverse C rarefaction compression longitudinal D rarefaction compression transverse
Mark scheme: A
Q38 · A power supply causes a current in a circuit
38 A power supply causes a current in a circuit. The electromotive force (e.m.f.) of the power supply and the resistance of the circuit are both changed. Which pair of changes must result in a smaller current in the circuit? e.m.f. resistance A decreased decreased B decreased increased C increased decreased D increased increased
Mark scheme: B
Q39 · There is a current of 0.25 A in a wire
39 There is a current of 0.25 A in a wire. How long does it take for 120 C of charge to pass a point in the wire? A 0.50 minutes B 8.0 minutes C 30 minutes D 480 minutes
Mark scheme: B
Q40 · The diagram shows an electric circuit
40 The diagram shows an electric circuit. 8.0 V 2.0 A 4.0 Ω The battery of electromotive force (e.m.f.) 8.0 V produces a current of 2.0 A in a 4.0 resistor. How much power is delivered to the resistor? A 0.25 W B 4.0 W C 16 W D 64 W
Mark scheme: C
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.
3Elements, compounds and mixtures2Gas exchange in humans2Sexual reproduction in plants2Alkenes1Cell structure1Chromatography1Diet1Digestive system1Drugs1Electrical circuits1Electrical quantities1Electrolysis1Energy flow1Enzymes1Exothermic and endothermic reactions1Extraction of metals1Forces1Formulas1General properties of waves1Group I properties1Identification of ions and gases1Kinetic particle model of matter1Light1Mass and weight1Motion1Photosynthesis1Preparation of salts1Rate of reaction1Redox1Sexual reproduction in humans1Sound1Terminology1Transfer of thermal energy1Transpiration1What you needed in this session
Cambridge’s own grade thresholds for 2020 Oct/Nov, Paper 2 · Variant 1. A higher threshold means an easier paper — the bar moves with how the cohort did.