Cambridge IGCSE Sciences - Co-ordinated (Double) 0654 — 2013 Oct/Nov Paper 2 · Variant 2

This document consists of 28 printed pages. IB13 11_0654_22/5RP © UCLES 2013 [Turn over *6115638287* UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CO-ORDINATED SCIENCES 0654/22 Paper 2 (Core) October/November 2013 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. Electronic calculators may be used. You may lose marks if you do not show your working or if you do not use appropriate units. A copy of the Periodic Table is printed on page 28. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question.

2 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 1 (a) Fig. 1.1 shows apparatus that can be used to test the electrical conductivity of the materials contained in the beakers Q, R and S. + – powdered sulfur copper chloride solution iron S R Q A low voltage d.c. supply positive electrode negative electrode Fig. 1.1 (i) Describe briefly how the apparatus is used to test the electrical conductivity of the contents of the beakers. [2] (ii) Predict and explain the results that are expected when the contents of beakers Q and S are tested for electrical conductivity. beaker Q prediction explanation beaker S prediction explanation [3]

3 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (iii) When the solution in beaker R is tested, the following observations are made. • Bubbles of gas form on the surface of the positive electrode. • A layer of an orange solid appears on the surface of the negative electrode. Name the gas that forms and the substance in the orange layer. gas orange layer [2] (iv) State the name of the process described in (iii). [1] (v) Describe a safe chemical test for the gas you have named in (iii). test result [2] (b) Fig. 1.2 shows a diagram that represents the way in which the particles in solid sodium chloride are arranged. Na+ Cl – Cl – Cl – Cl – Cl – Cl – Cl – Cl – Cl – Na+ Na+ Na+ Fig. 1.2 (i) State, in terms of electrons, what happens to an atom of sodium, Na, when it is changed into an ion of sodium, Na+. [1] (ii) Explain why the sodium and chloride ions stay bonded together in a crystal of sodium chloride. [2]

4 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 2 (a) Use the words or phrases below to complete the sentences. amplitudes frequencies slows down speed speeds up Each word or phrase can be used once, more than once or not at all. (i) Light when it travels from air to glass. (ii) In the electromagnetic spectrum, the waves are arranged in order of . (iii) 20 Hz to 20 000 Hz is the approximate human range of audible . (iv) The of sound waves determines the loudness of the sounds. [4] (b) Fig. 2.1 shows a demonstration of sound transmission using a bell jar. air to vacuum pump 12 1 2 3 4 5 6 7 8 9 10 11 Fig. 2.1 As the air is removed from the bell jar, the ringing sound from inside the bell jar gets quieter. When all the air has been removed, the bell cannot be heard. Explain these observations. [2]

5 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (c) Fig. 2.2 shows a light ray entering an optical fibre at one end. light ray optical fibre Fig. 2.2 The light ray travels all the way through the optical fibre. Explain why the light ray is able to stay inside the optical fibre. You may draw on the diagram if it helps your answer. [2]

6 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 3 (a) Fig. 3.1 shows cross-sections of a root and a stem. stem root xylem phloem Fig. 3.1 (i) On Fig. 3.1, use label lines to indicate the positions of the xylem and phloem on the diagram of the stem. [2] (ii) Describe the functions of xylem and phloem. xylem phloem [4]

7 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (b) The roots of most plants have root hairs near their tips. Researchers grew two types of plants, A and B, in soil with different concentrations of phosphate ions. They measured the mean number of root hairs in a small area of the roots, and also the mean length of the root hairs. Table 3.1 shows their results. Table 3.1 type of plant phosphate concentration mean number of root hairs per unit area mean length of root hairs / micrometres low 1.26 175 A high 1.70 149 low 1.41 225 B high 1.85 52 (i) Describe two ways in which the addition of phosphate ions to the soil affects the root hairs in type A plants. 1 2 [2] (ii) Compare the effect of adding phosphate ions to the soil for type A plants and for type B plants. [2] (iii) Explain why a reduction in the length of its root hairs could reduce the rate of growth of a plant. [3]

8 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (c) Farmers often add fertilisers containing phosphate ions, potassium ions and nitrate ions to the soil in which they grow crops. Explain why adding nitrate ions to the soil helps the crop plants to grow faster and larger. [2]

9 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use 4 Sodium hydrogencarbonate, NaHCO3, is a white solid compound which is soluble in water. (a) A student adds some sodium hydrogencarbonate to a beaker which contains an aqueous solution of full range indicator (Universal Indicator). spatula solution of full range indicator sodium hydrogencarbonate When the sodium hydrogencarbonate dissolves, the solution changes colour from green to blue. (i) State and explain how the pH of the mixture changes when the sodium hydrogencarbonate dissolves. [2] (ii) The student then added excess dilute hydrochloric acid to the blue solution. State what is observed to show that the reaction in the large test-tube has finished. [2]

10 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (b) Fig. 4.1 shows apparatus a teacher uses to demonstrate the heating of sodium hydrogencarbonate. limewater u-tube cold water cobalt chloride paper large test-tube sodium hydrogencarbonate NaHCO3 heat Fig. 4.1 The solid sodium hydrogencarbonate is heated strongly for a few minutes. • The cobalt chloride paper changes colour from blue to pink. • A gas bubbles out through the limewater, turning it cloudy. After the reaction, a white solid remains in the large test-tube. (i) Explain how the observations show that both water and carbon dioxide are produced. [2] (ii) State the observation that shows that the reaction has finished. [1]

11 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (iii) The white solid that remains in the test-tube when the reaction is finished is sodium carbonate. Predict and explain how the mass of the remaining sodium carbonate compared to the mass of the original sodium hydrogencarbonate. prediction explanation [2] (iv) Suggest the word chemical equation for the reaction that occurs when sodium hydrogencarbonate is heated. sodium hydrogencarbonate + + [1]

12 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 5 (a) Fig. 5.1 shows a bicycle with two lights A and B at the front. A B Fig. 5.1 Fig. 5.2 shows the circuit used to power the two lights. B A Fig. 5.2 (i) State the name given to this type of circuit arrangement. [1] (ii) To calculate the resistance of light A, the current flowing through it and the voltage across it must be measured. On Fig. 5.2, using the correct symbols, draw an ammeter and a voltmeter correctly connected to make these measurements. [2]

13 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (iii) The resistance of light A in the circuit is 5 Ω and the resistance of light B is 10 Ω. Calculate the combined resistance of the two lights. State the formula that you use and show your working. formula working Ω [2] (iv) The voltage supplied by the battery is 9 V. Calculate the current passing through the circuit. State the formula that you use and show your working. formula working A [2] (b) The bicycle was made from a block of aluminium alloy of mass 9000 g and volume 3000 cm3. Calculate the density of aluminium in g / cm3. State the formula that you use and show your working. formula working g / cm3 [2]

14 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (c) The bicycle is ridden by a cyclist. The cyclist is cooled by sweating. Explain, in terms of particles, how sweating cools his body. [3]

15 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use 6 Fig. 6.1 shows the male reproductive system. A B C Fig. 6.1 (a) Name the parts labelled A, B and C. A B C [3] (b) When a sperm cell fuses with an egg cell, a zygote is produced which may eventually develop into a baby. Explain why it is the sperm cell, not the egg cell, that determines the sex of the baby. [3] (c) HIV / AIDS is a disease that can be passed on by sexual intercourse. (i) What does HIV stand for? [1] (ii) State one way in which a man with HIV / AIDS can avoid passing it to another person. [1]

16 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 7 (a) The elements chlorine, bromine and iodine are found in Group 7 of the Periodic Table. (i) Complete Table 7.1 by writing the physical state (solid, liquid or gas) at room temperature (20 °C) of the elements. Table 7.1 element physical state bromine iodine [1] (ii) Explain why an iodine atom is larger and heavier than a bromine atom. [2] (iii) An aqueous solution containing chlorine is added to a colourless solution of potassium iodide. chlorine solution colourless solution of potassium iodide Describe and explain briefly what is observed in this reaction. observation explanation [2]

17 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (b) Explain why a dilute solution of chlorine is usually added to drinking water before it is supplied to homes. [2] (c) Helium is a gas found in Group 0 of the Periodic Table. Some helium is added to a flask containing chlorine and left for a few days. Predict and explain whether the flask now contains a mixture of the two elements or a compound. [2]

18 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 8 (a) Fig. 8.1 shows a car moving along a road. (i) Draw and label arrows on Fig. 8.1 to show the directions of the driving and friction forces acting on the car. [1] Fig. 8.1 (ii) State one source of friction on the moving car. [1] (iii) The driving and friction forces are balanced. Explain what is meant by the phrase forces are balanced. [1] (iv) Describe the movement of the car when these forces are balanced. [1] (v) Apart from the driving and friction forces there are other forces acting on the car. Name one of these forces. [1] (b) (i) The car travels a distance of 400 m down a hill in 25 seconds. Calculate the average speed of the car. State the formula that you use and show your working. formula working m / s [2]

19 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (ii) The car is going faster at the bottom of the hill than it was at the top. State the type of energy which the car has gained. [1] (iii) State the type of energy which the car will have lost as it travels down the hill. [1] (c) By the end of the car’s journey, the temperature of the air in the tyres has increased. The volume of the air in the tyres remained the same. Explain, in terms of particles, what happened to the pressure of the air in the tyres during this heating process. [2]

20 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 9 Rabbits are often kept as pets. People try to breed rabbits with unusual colours, such as himalayan colouring. Fig. 9.1 shows a rabbit with himalayan fur colour. The rabbit's fur is white with some black areas. Fig. 9.1 (a) Completely-white fur and himalayan-coloured fur are produced by two alleles of a gene. The allele for white colour, F, is dominant to the allele for himalayan colour, f. (i) Define the term dominant. [1] (ii) State the phenotype of a rabbit that is heterozygous for these alleles. [1]

21 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use (iii) Complete the genetic diagram to explain the results of crossing two rabbits that are heterozygous for these alleles. genotype of parents gametes … and … and and gametes from one parent gametes from the other parent Ff [3] (iv) State the ratio of offspring that you would expect from this cross. ratio of white : himalayan offspring = : [1] (b) Rabbits, like humans, keep their internal body temperature constant. The body temperature of a rabbit is 38.5 °C. Respiration transforms chemical potential energy to heat energy, which helps to keep the body temperature above the temperature of the rabbit's environment. (i) Describe how respiration transforms chemical potential energy to heat energy. [2]

22 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (ii) Suggest how the fur of a rabbit helps to maintain its body temperature higher than that of its environment. [2] (iii) When himalayan rabbits are first born, they are white all over. The black colour develops gradually. The black pigment is produced by the action of an enzyme that is only active at temperatures below 25 °C. Use this information to suggest a reason for the distribution of black fur on the body of a himalayan rabbit. [2]

23 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use 10 (a) Fig. 10.1 shows names and molecular structure diagrams of some compounds containing carbon. (i) Draw straight lines to match the structures with names. One line has been drawn as an example. C H H C H H C H H H H C H H C H H H C H H H H C H H C H H H O C H H C H H H H ethane ethene methane ethanol propane Fig. 10.1 [3] (ii) State two uses of ethanol. 1 2 [2]

24 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (b) Fig. 10.2 shows the structure of one molecule of a type of compound called a CFC (chlorofluorocarbon). C Cl Cl F F Fig. 10.2 (i) State the chemical formula of the molecule whose structure is shown in Fig. 10.2. [1] (ii) State the type of chemical bonding between the atoms in the molecule in Fig. 10.2. Give a reason for your answer. type of bonding reason [2]

25 © UCLES 2013 0654/22/O/N/13 [Turn over For Examiner's Use 11 (a) (i) Draw lines to show the magnetic field around the bar magnet in Fig. 11.1. S N Fig. 11.1 [2] (ii) Draw lines to show the shape of the magnetic field produced by the solenoid coil in Fig. 11.2 when an electric current passes through it. Fig. 11.2 [1] (iii) The magnet in Fig. 11.1 is a permanent magnet. The magnet in Fig. 11.2 is an electromagnet. Suggest one advantage of using an electromagnet rather than a permanent magnet. [1]

26 © UCLES 2013 0654/22/O/N/13 For Examiner's Use (b) Fig. 11.3 shows a wire passing between the poles of a permanent magnet. The wire moves upwards, when the switch is closed. N S direction of current direction of field flexible wire direction of motion produced Fig. 11.3 (i) Use the words or phrases below to complete the sentences. current electrical gravitational magnetic resistance stronger weaker Each word may be used once, more than once or not at all. The wire moves because of the force produced when the field of the permanent magnet interacts with the magnetic field caused by the in the wire. The force can be increased by using a magnet. [3] (ii) Describe two ways by which the direction of motion of the wire could be reversed. 1 2 [2]

27 © UCLES 2013 0654/22/O/N/13 For Examiner's Use 12 (a) Fig. 12.1 shows a food web in the Antarctic Ocean. microscopic green plants e.g. algae krill blue whale squid dolphin sperm whale killer whale fish penguin Fig. 12.1 (i) State the term used for organisms such as the microscopic green plants that make their own organic nutrients. [1] (ii) Name one organic nutrient that is made by the green plants. [1] (iii) State what is shown by the arrows in the food web. [1] (b) There is concern that global warming will damage the environment in the Antarctic Ocean. Name two gases that contribute to global warming. 1 2 [2]

28 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. © UCLES 2013 0654/22/O/N/13 Group 140 Ce Cerium 58 141 Pr Praseodymium 59 144 Nd Neodymium 60 Pm Promethium 61 150 Sm Samarium 62 152 Eu Europium 63 157 Gd Gadolinium 64 159 Tb Terbium 65 162 Dy Dysprosium 66 165 Ho Holmium 67 167 Er Erbium 68 169 Tm Thulium 69 173 Yb Ytterbium 70 175 Lu Lutetium 71 232 Th Thorium 90 Pa Protactinium 91 238 U Uranium 92 Np Neptunium 93 Pu Plutonium 94 Am Americium 95 Cm Curium 96 Bk Berkelium 97 Cf Californium 98 Es Einsteinium 99 Fm Fermium 100 Md Mendelevium 101 No Nobelium 102 Lr Lawrencium 103 1 H Hydrogen 1 7 Li Lithium 3 23 Na Sodium 11 24 Mg Magnesium 12 40 Ca Calcium 20 45 Sc Scandium 21 48 Ti Titanium 22 51 V Vanadium 23 52 Cr Chromium 24 55 Mn Manganese 25 56 Fe Iron 26 59 Co Cobalt 27 59 Ni Nickel 28 64 Cu Copper 29 65 Zn Zinc 30 70 Ga Gallium 31 27 Al Aluminium 13 11 B Boron 5 12 C Carbon 6 14 N Nitrogen 7 16 O Oxygen 8 19 F Fluorine 9 28 Si Silicon 14 31 P Phosphorus 15 32 S Sulfur 16 35.5 Cl Chlorine 17 40 Ar Argon 18 20 Ne Neon 10 4 He Helium 2 73 Ge Germanium 32 75 As Arsenic 33 79 Se Selenium 34 80 Br Bromine 35 84 Kr Krypton 36 39 K Potassium 19 88 Sr Strontium 38 89 Y Yttrium 39 91 Zr Zirconium 40 93 Nb Niobium 41 96 Mo Molybdenum 42 Tc Technetium 43 101 Ru Ruthenium 44 103 Rh Rhodium 45 106 Pd Palladium 46 108 Ag Silver 47 112 Cd Cadmium 48 115 In Indium 49 119 Sn Tin 50 122 Sb Antimony 51 128 Te Tellurium 52 127 I Iodine 53 131 Xe Xenon 54 137 Ba Barium 56 139 La Lanthanum 57 * 178 Hf Hafnium 72 181 Ta Tantalum 73 184 W Tungsten 74 186 Re Rhenium 75 190 Os Osmium 76 192 Ir Iridium 77 195 Pt Platinum 78 197 Au Gold 79 201 Hg Mercury 80 204 Tl Thallium 81 207 Pb Lead 82 209 Bi Bismuth 83 Po Polonium 84 At Astatine 85 Rn Radon 86 Fr Francium 87 227 Ac Actinium 89 9 Be Beryllium 4 I II III IV V VI VII 0 85 Rb Rubidium 37 133 Cs Caesium 55 226 Ra Radium 88 The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p.). a X b a = relative atomic mass X = atomic symbol b = proton (atomic) number Key *58-71 Lanthanoid series 90-103 Actinoid series DATA SHEET The Periodic Table of the Elements

CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2013 series 0654 CO-ORDINATED SCIENCES 0654/22 Paper 2 (Core Theory), maximum raw mark 120 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the October/November 2013 series for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level components.

Page 2 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 1 (a) (i) electrodes made to contact the contents ; positive reading on ammeter / if there’s a current then shows conduction ; [2] (ii) Q conductor and S insulator ; iron is a metal ; sulfur is a non-metal ; [3] (iii) chlorine ; copper ; [2] (iv) electrolysis ; [1] (v) reference to use of damp indicator paper / solution of indicator ; decolourised ; [2] (b) (i) loses electron ; each atom loses one electron / now protons – electrons = 1 ; [max 1] (ii) sodium and chloride ions have opposite (electrical) charge ; reference to force of attraction (between opposite charges) ; [2] [Total: 13] 2 (a) (i) slows down ; [1] (ii) frequencies ; [1] (iii) frequencies ; [1] (iv) amplitudes ; [1] (b) sound waves travel by vibration of medium / particles ; as the air is sucked out there is less of a medium / particles to convey the sound wave ; no air / vacuum / medium means sound waves cannot pass through ; [max 2] (c) reflection ; total internal ; when angle is greater than critical angle ; [max 2] [Total: 8]

Page 3 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 3 (a) (i) label to xylem ; label to phloem ; [2] (ii) xylem: transports water ; transports, mineral ions / named ion ; provides support ; phloem: transports nutrients ; made in leaves / by photosynthesis ; e.g. sucrose / sugar ; [max 4] (b) (i) more root hairs ; shorter root hairs ; [2] (ii) increase in number in both types is, the same / 0.44 more root hairs per unit area ; decrease in length is much greater in plant Bs ; [2] (iii) (roots have) reduced surface area ; less able to take up water / mineral ions ; (reduced water) causes reduced photosynthesis ; less glucose made ; glucose used for energy / respiration ; for growth / building up large molecules building cell walls ; less nitrate (uptake) reduces protein synthesis ; less phosphate (uptake) reduces cell membrane synthesis ; less magnesium (uptake) reduces chlorophyll synthesis ; less potassium (uptake) reduces protein synthesis ; [max 3] (c) nitrate used to make, amino acids / proteins / chlorophyll production ; proteins needed to make new cells ; [2] [Total: 15] 4 (a) (i) increased ; because mixture has become more alkaline ; [2] (ii) colour change (blue) to red ; effervescence stops / (gas) bubbles stop being produced ; [2]

Page 4 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 (b) (i) colour change of cobalt chloride paper shows water ; and cloudy limewater shows carbon dioxide ; [2] (ii) no more gas bubbles through limewater ; [1] (iii) sodium carbonate has lower mass ; matter in the form of carbon dioxide and water has been removed ; [2] (iv) sodium → sodium + carbon + water ; [1] hydrogencarbonate carbonate dioxide [Total: 10] 5 (a) (i) series ; [1] (ii) ammeter with correct symbol in series ; voltmeter with correct symbol in parallel ; [2] (iii) RT = R1 + R2 ; = 15 Ω ; [2] (iv) I = V/R ; 9/15 = 0.6 A ; [2] (b) density = mass/volume ; = 9000/3000 = 3.0 (g / cm3) ; [2] (c) heat transferred from body to sweat / heat absorbed by sweat from athlete’s body / heat energy in body reduced by sweating ; kinetic energy of water molecules increases / water molecules move faster ; faster moving / more energetic (water) molecules escape / leave the surface / water molecules turn to gas / vapour ; break bonds / break forces of attraction between molecules ; (KE) / energy of (remaining) water molecules (in sweat) decreases ; [max 3] [Total: 12] 6 (a) A penis ; B sperm duct ; C urethra ; [3] (b) reference to X and Y chromosomes ; male XY and female XX ; sperm can be X or Y ; eggs all X ; [max 3]

Page 5 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 (c) (i) human immunodeficiency virus ; [1] (ii) not have sexual intercourse / wear a condom ; (allow other methods e.g. not sharing needles / must not donate blood) [1] [Total: 8] 7 (a) (i) liquid AND solid ; (both required) [1] (ii) iodine atom has more electron shells than bromine ; iodine atom contains more protons, neutrons (and electrons) than bromine ; [2] (iii) mixture becomes brown ; because iodine is produced / because iodine is displaced / because chlorine ; is more reactive than iodine ; [max 2] (b) to kill harmful bacteria / microorganisms ; to make water safe for humans ; [2] (c) flask contains a mixture / chlorine and helium atoms have not bonded ; because helium is noble gas / inert ; [2] [Total: 9] 8 (a) (i) driving force forwards and friction forces backwards ; [1] (ii) air resistance / tyres on road / brakes ; [1] (iii) equal and opposite ; [1] (iv) constant speed ; [1] (v) gravity / weight ; [1] (b) (i) speed = distance/time ; = 400/25 = 16 m/s ; [2] (ii) kinetic ; [1] (iii) gravitational / potential ; [1] (c) pressure increases ; particles move faster therefore more frequent collisions with tyre walls ; [2]

Page 6 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 9 (a) (i) has an effect whenever present ; [1] (ii) white ; [1] (iii) (parents’ genotypes) Ff and Ff ; gametes F and f from both parents, ; offspring genotypes FF, Ff, Ff and ff ; [3] (iv) 3:1 ; [1] (b) (i) oxygen combined with glucose ; chemical energy in glucose transferred to (heat) energy ; exothermic reaction ; [max 2] (ii) fur traps air ; fur / air, acts as an insulator ; reduces heat loss by, convection / radiation ; [max 2] (iii) ears / paws / nose, colder than other parts of body ; black pigment produced in colder areas ; enzyme is active in these areas ; [max 2] [Total: 12]

Page 7 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 10 (a) (i) (4 correct = 3 marks, 2/3 correct = 2 marks, 1 correct = 1 mark) ;;; [3] (ii) fuel ; solvent ; in drinks ; (allow other correct) [max 2] (b) (i) CF2Cl2 ; (allow elements in any order) [1] (ii) covalent ; non-metallic atoms bonded ; [2] [Total: 8]

Page 8 Mark Scheme Syllabus Paper IGCSE – October/November 2013 0654 22 © Cambridge International Examinations 2013 11 (a) (i) shape ; arrow direction ; [2] (ii) [1] (iii) advantage – can be turned on and off / can have variable strength / can be stronger ; [1] (b) (i) magnetic ; current ; stronger ; [3] (ii) reverse current ; reverse magnetic field ; [2] 12 (a) (i) producer ; [1] (ii) carbohydrate / glucose / sugar / sucrose ; [1] (iii) energy (flow / transfer) ; [1] (b) carbon dioxide ; methane ; [2] [Total: 5] S N