Cambridge IGCSE Science - Combined 0653 — 2011 Oct/Nov Paper 3 · Variant 3

This document consists of 20 printed pages. IB11 11_0653_33/4RP © UCLES 2011 [Turn over *5727661480* For Examiner's Use 1 2 3 4 5 6 7 8 9 Total UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMBINED SCIENCE 0653/33 Paper 3 (Extended) October/November 2011 1 hour 15 minutes 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 soft pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 24. 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. www.XtremePapers.com

2 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 1 There are three states of matter – solid, liquid and gas. Fig. 1.1 shows the arrangement of particles in a solid. Fig. 1.1 (a) (i) Draw similar diagrams for a liquid and a gas. liquid gas [2] (ii) Explain the arrangements you have drawn in terms of the forces between the particles. [2]

3 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (b) Explain the following using the ideas of conduction, convection and radiation. (i) Houses in hot climates are often painted white. [1] (ii) A saucepan has a metal base but a plastic or wooden handle. [1] (iii) In a kettle, the water is heated at the bottom but all of the water in the kettle becomes hot. [2]

4 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 2 (a) Fig. 2.1 shows a flowering plant, and two cells from the plant. cell A cell B X Fig. 2.1 (i) On Fig. 2.1, draw a line from each cell to a part of the plant in which it could be found. [2] (ii) Explain why cell A contains the structures labelled X, but cell B does not. [3] (iii) Suggest how the shape of cell B adapts it for its function. [2]

5 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (b) The colour of the flower petals is determined by a gene with two alleles, R and r. Allele R is dominant and produces red flowers, and allele r produces white flowers. (i) Complete Table 2.1 to show the phenotype produced by each of the three possible genotypes. Table 2.1 genotype phenotype RR Rr rr [1] (ii) On Table 2.1, draw a circle around one heterozygous genotype. [1] (iii) Predict the ratio of red to white flowers that would be produced if two plants with the genotypes Rr were crossed. [1] (c) A grower has a rare variety of orchid with unusual flowers. She decides to produce new plants from this orchid using an asexual method of propagation. Suggest the advantages to the grower of using asexual propagation to produce new plants, rather than sowing seeds she has collected from the orchid plant. [2]

6 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 3 (a) Fig. 3.1 shows apparatus a student used to investigate the electrolysis of a solution of potassium sulfate. d.c. electrical power supply + – platinum anode platinum cathode potassium sulfate solution R Q Fig. 3.1 During the experiment shown in Fig. 3.1, two different colourless gases, Q and R, collected in the small test-tubes. Neither of these gases contained any sulfur. (i) Name gases Q and R. Q R [2] (ii) Choose one of the gases, Q or R, and describe how the student should test it for the gas you have named. chosen gas test [1]

7 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (b) Potassium sulfate solution is made in a neutralisation reaction between an acid and an alkali. ALKALI ACID Fig. 3.2 (i) Suggest a word chemical equation for a reaction between a suitable acid and alkali that would produce potassium sulfate. + + potassium sulfate [2] (ii) Describe how a neutral solution of potassium sulfate could be obtained using suitable solutions of an acid and an alkali. [3] (iii) State the ionic equation which describes the neutralisation reaction between any aqueous acid and any aqueous alkali. [2]

8 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 4 (a) Five types of radiation are listed below. alpha radiation beta radiation gamma radiation infra–red radiation ultraviolet radiation (i) State which of these types of radiation is a stream of electrons. [1] (ii) State which of these types of radiation are forms of electromagnetic radiation. [2] (iii) State one use for gamma radiation. [1] (iv) Complete Table 4.1 to compare alpha, beta and gamma radiations. Tick one box in each row of the table. Table 4.1 alpha beta gamma most penetrating most ionising not deflected by an electric field [2]

9 1© UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (b) Some students measured the level of radiation from a radioactive source for 42 days. Table 4.2 shows the results corrected for background radiation. Table 4.2 time / days 0 7 14 21 28 35 42 level of radiation / average counts per minute 64 45 33 23 16 12 8 Describe and explain the pattern in these results. [2]

10 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 5 PTFE is an important plastic which has many uses in the home and industry. PTFE is made of polymer molecules. Fig. 5.1 shows the displayed formula of the monomer that reacts to produce PTFE. F C F F C F Fig. 5.1 (a) (i) Explain why the molecule shown in Fig. 5.1 is not a hydrocarbon. [1] (ii) Fig. 5.2 shows the outer shell electrons in a carbon atom and a fluorine atom. F C Fig. 5.2 Complete the bonding diagram below to show how the outer electrons are arranged in the molecule whose displayed formula is shown in Fig. 5.1. C F F F F C [2]

11 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (iii) Complete the diagram below to show the displayed formula of a small section of a PTFE molecule. Your completed formula must contain eight fluorine atoms. F C F [3] (b) The element, fluorine, is a halogen in Group 7 of the Periodic Table. (i) Use your knowledge of the physical states of the other halogens to predict and explain whether fluorine is a solid, a liquid or a gas at room temperature. prediction explanation [2] (ii) Use your knowledge of the reactivities of the other halogens to predict and explain whether or not the following halogen displacement reaction will occur. bromine + sodium fluoride → sodium bromide + fluorine [2]

12 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 6 Fig. 6.1 shows the human digestive system. Fig. 6.1 (a) On Fig. 6.1, use label lines to label the stomach, the colon. [2] (b) On Fig. 6.1, label and name one part of the digestive system that food does not pass through on its way from mouth to anus. [1] (c) Describe how digestion takes place inside the stomach. [2]

13 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (d) Fig. 6.2 shows a food web involving humans. tomato plant whitefly human predatory wasp Fig. 6.2 If there are a lot of whitefly feeding on the tomato plants, there will be fewer tomatoes for humans to eat. (i) Use the information in Fig. 6.2 to suggest how biological control could be used to control the whitefly population. [1] (ii) State two reasons, other than cost, why this could be a better way of controlling the whitefly than using pesticides. 1 2 [2]

14 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 7 Some coffee drinks are sold in self-heating cans. Fig. 7.1 shows a cross-sectional diagram of one design of self-heating can. calcium oxide thin metal sheet water coffee drink pin Fig. 7.1 Fig. 7.2 shows the can after it has been turned upside down and the pin pushed through the thin metal sheet. This allows the water to fall into the calcium oxide. pin pushed down coffee drink becomes hot Fig. 7.2 (a) Explain briefly why the coffee drink in the self-heating can becomes hot when the water and calcium oxide mix. [2]

15 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (b) (i) Use the position of calcium in the Periodic Table to explain why the electrical charge of a calcium ion is + 2. [3] (ii) The reaction between calcium oxide and water produces the ionic compound calcium hydroxide, Ca(OH)2. Deduce the electrical charge of the hydroxide ion. Show how you obtained your answer. [2]

16 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 8 (a) A student set up the circuit shown in Fig. 8.1 to investigate the relationship between the voltage across resistor R and the current through resistor R. X R Y Fig. 8.1 (i) Name the meters labelled X and Y. X Y [1] (ii) Explain the purpose of the variable resistor in the circuit. [1]

17 © UCLES 2011 0653/33/O/N/11 [Turn over For Examiner's Use (iii) Fig. 8.2 shows a graph of the results. 0 1 2 3 4 5 3 2 1 0 voltage / V current / A Fig. 8.2 Use the data on the graph to calculate the resistance of resistor R. State the formula that you use and show your working. formula used working [2] (b) Two 10 ohm resistors are placed in parallel in a circuit. Calculate their total resistance. State the formula that you use and show your working. formula used working [3]

18 © UCLES 2011 0653/33/O/N/11 For Examiner's Use (c) Fig. 8.3 shows a battery-operated d.c. electric motor driving a fan. When an electric current passes through the coil it rotates. N S magnet split rings rotating coil Fig. 8.3 (i) Describe what happens to the coil if the poles of the magnets are reversed and the rest of the circuit remains the same. [1] (ii) Describe what happens if a greater electric current is passed through the coil. [1] (iii) Explain the purpose of the split rings. [2]

19 © UCLES 2011 0653/33/O/N/11 For Examiner's Use 9 A man walking along a road decided to cross to the other side. As he was walking across the road, a car sounded its horn, which made him jump. He then crossed the rest of the road more quickly. (a) For each of the actions that the man took, state whether it was a reflex action or a voluntary action. walking along the road walking across the road jumping in response to the car horn crossing the road more quickly [2] (b) Explain one advantage and one disadvantage of reflex actions over voluntary actions. advantage disadvantage [2] (c) State the roles of each of the following parts of the nervous system in a reflex action. receptor motor neurone [2]

20 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 2011 0653/33/O/N/11 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

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the October/November 2011 question paper for the guidance of teachers 0653 COMBINED SCIENCE 0653/33 Paper 3 (Extended Theory), maximum raw mark 80 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 must be read in conjunction with the question papers and the report on the examination. • Cambridge will not enter into discussions or correspondence in connection with these mark schemes. Cambridge is publishing the mark schemes for the October/November 2011 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2011 0653 33 © University of Cambridge International Examinations 2011 1 (a) (i) liquid – particles touching but random arrangement ; gas – particles well spaced out, random arrangement ; [2] (ii) forces greater in a liquid than in a gas, ora ; reference to forces of attraction / forces holding particles together ; [2] (b) (i) white surfaces reflect the radiation well (better than dark surfaces) / poor absorbers of radiation ; [1] (ii) metal base is a good heat conductor / wood / plastic handle is a good heat insulator / poor conductor ; [1] (iii) convection ; hot water expands and becomes less dense ; hot water rises (and displaces colder water) ; [max 2] [Total: 8] 2 (a) (i) line from cell A to leaf ; line from cell B to root ; [2] (ii) structure X, is a chloroplast / contains chlorophyll / absorbs energy from light ; for photosynthesis ; cell B does not have them because it, is underground / gets no light ; [3] (iii) has a large surface area ; for uptake of, water / mineral salts ; [2] (b) (i) genotype phenotype RR red Rr red rr white ; [1] (ii) circle around Rr ; [1] (iii) 3 red : 1 white ; (if red and white not stated, assume first number refers to red) [1] (c) all new plants identical to parent plant ; genetically identical / clone; if used seeds would produce variation / not have unusual flowers ; seeds may not germinate / (mature) plants obtained more quickly ; only one parent needed to produce the offspring ; [max 2] [Total: 12]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2011 0653 33 © University of Cambridge International Examinations 2011 3 (a) (i) Q – oxygen ; R – hydrogen ; [2] (ii) (oxygen) relights glowing (wooden) splint ; OR (hydrogen) pops with application of flame ; [max 1] (b) (i) potassium hydroxide + sulfuric acid ; (potassium sulfate +) water ; [2] (ii) addition of one reagent to the other ; slowly / carefully (until neutral) ; suitable method of testing neutrality ; detail of indication of neutrality e.g. pH meter shows 7 / universal indicator goes green ; [max 3] (iii) H+ + OH– ; H2O ; [2] [Total: 10] 4 (a) (i) beta radiation ; [1] (ii) gamma, infra-red, ultraviolet ;; [2] (iii) cancer treatment ; tracer ; food sterilization ; surgical instrument sterilization ; [max 1] (iv) alpha beta gamma most penetrating ✓ most ionising ✓ not deflected by an electric field ✓ ;; (3 correct for 2 marks ; 2 correct for 1 mark) [2] (b) count rate decreased / decay curve ; some randomness of results ; half-life about 14 days ; [max 2] [Total: 8]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2011 0653 33 © University of Cambridge International Examinations 2011 5 (a) (i) no hydrogen / hydrocarbons contain carbon and hydrogen (only) ; [1] (ii) bonding pairs ; non-bonding pairs ; [2] (iii) four C and 8 F ; all single bonds ; indication that chain continues ; [3] (b) (i) gas; boiling point decreases up the group / increases down the group / description of trend in physical state in group ; [2] (ii) (no reaction) reactivity increases up the group ; so bromine is less reactive than fluorine ; [2] [Total: 10] 6 (a) label to stomach ; label to colon ; [2] (b) label to liver / pancreas / gall bladder / tongue / salivary gland ; [1] (c) protease / pepsin ; breaks down proteins ; to, amino acids / polypeptides / peptides ; hydrochloric acid provides low pH / acid conditions for pepsin enzymes ; [max 2]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2011 0653 33 © University of Cambridge International Examinations 2011 (d) (i) put predatory wasps on the plants ; [1] (ii) pesticides can harm people who eat the tomatoes ; pesticides could harm other (beneficial) insects ; whitefly could become resistant to pesticides ; might need to apply pesticides often / only need to add wasps once ; [max 2] [Total: 8] 7 (a) calcium oxide and water react ; (reaction is) exothermic / reaction produces heat ; heat transferred to coffee ; [max 2] (b) (i) calcium is in Group 2 / atoms have two outer electrons ; outer 2 electrons lost ; ion has two more positive charges (protons) than negative charges (electrons) ; [3] (ii) single negative ; working to show need for charge balance ; [2] [Total: 7] 8 (a) (i) X = voltmeter and Y = ammeter ; [1] (ii) changing / controlling voltage / current in circuit / across resistor ; [1] (iii) resistance = voltage ÷ current / 1 ÷ gradient ; = 4 / 2 (or other correct values) = 2 Ω ; [2] (b) 1 / R = 1 / R1 + 1 / R2 ; = 1 / 10 + 1 / 10 ; R = 10 / 2 = 5 Ω ; [3] (c) (i) changes direction ; [1] (ii) spins faster ; [1] (iii) allows current to change direction in coil (every ½ turn) ; means force on coil stays in same direction ; keeps coil spinning in same direction ; [max 2] [Total: 11]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – October/November 2011 0653 33 © University of Cambridge International Examinations 2011 9 (a) voluntary voluntary reflex voluntary (one mark for any two correct) ;; [2] (b) (advantage) faster ; (disadvantage) no choice / cannot make the best decision ; [2] (c) (receptor) receives stimulus / senses change in the environment / hears the sound ; (motor neurone) transmits, nerve impulse / signal, to an, effector / muscle ; [2] [Total: 6]