Cambridge IGCSE Twenty-First Century Science 0608 — 2012 May/June Paper 4 · Variant 1

This document consists of 15 printed pages and 1 blank page. DC (NS/SW) 51580/3 © UCLES 2012 [Turn over UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education * 7 9 3 6 3 2 0 2 8 9 * TWENTY FIRST CENTURY SCIENCE 0608/04 Paper 4 May/June 2012 1 hour 30 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 pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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. For Examiner’s Use 1 2 3 4 5 6 7 8 9 Total www.XtremePapers.com

2 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 1 The table shows some chemicals commonly used to colour processed foods. name colour source beta-carotene orange carrots carmoisine red synthesised lycopene red tomatoes sunset yellow yellow synthesised tartrazine yellow synthesised xanthophyll yellow plant leaves (a) Some data suggest that carmoisine, sunset yellow and tartrazine may cause hyperactivity in children. There is no evidence to suggest that beta-carotene, lycopene or xanthophyll cause hyperactivity. Use information in the table to suggest which sort of food colourings may cause hyperactivity and which do not. … … …[2] (b) A pressure group wants a government to ban the use of carmoisine, sunset yellow and tartrazine in processed food. (i) Explain how the government would be applying the precautionary principle if they did this. … … …[2] (ii) A government spokesman says that a ban is not necessary. He says that work carried out by a scientific advisory committee means that use of these additives in food is safe. Suggest what scientific advisory committees do to make sure that the use of food additives is safe. … … …[2] [Total: 6]

3 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use 2 Scientists look at data from an industrialised country. They compare the distance travelled by motor vehicles and the number of asthma patients. 1950 0 100 200 300 400 500 600 distance travelled in billions of km 1970 1990 year 2010 1950 number of asthma patients 1970 1990 year 2010 (a) Describe the connection between the data shown in the two graphs. … … …[2] (b) The scientists think that particulates produced by vehicle engines can cause asthma. Explain why the data does not prove this idea and suggest what further information would support the idea. … … … …[2] (c) Suggest two ways that the amount of particulates produced by motor vehicles in this country could be reduced. … … … …[2] [Total: 6]

4 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 3 Scientists test the tensile strength of low density poly(ethene), LDPE, and high density poly(ethene), HDPE. Tensile strength is a measurement of how much the material can be pulled before it breaks. tensile strength / kPa LDPE HDPE sample 1 112 285 sample 2 106 279 sample 3 108 298 sample 4 111 282 sample 5 107 289 sample 6 110 284 best estimate 109 range 106 to 112 (a) (i) Work out the best estimate for the tensile strength of HDPE. Give your answer to the nearest kPa. Show your working. tensile strength of HDPE = … kPa [2] (ii) The scientists decide that there is a real difference between the tensile strength of LDPE and the tensile strength of HDPE. How does the data show this? … …[1] (b) Suggest which of the two types of poly(ethene) would be more suitable for making rope. Explain your choice. … … …[2]

5 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use (c) HDPE has higher crystallinity than LDPE. (i) Suggest another difference in structure that could explain the difference in properties of these two polymers. …[1] (ii) Explain how the difference in structure you have suggested in part (i) results in the difference in properties. Use ideas of forces and energy in your answer. … … … …[2] [Total: 8]

6 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 4 A puffin is a seabird found living around the coast of the UK. Puffins eat sand eels (small sea fish) which feed off plankton (small plants found in the sea). Puffins are predated by rats, stoats and seagulls. (a) Complete the food web using the information above to help you. Add the arrow heads correctly. [2]

7 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use (b) Competition for resources can occur between organisms in a food web. Interspecific competition occurs between two organisms of different species. Intraspecific competition occurs between two organisms of the same species. Give an example of each type of competition using organisms from this food web. interspecific competition … … intraspecific competition … …[2] (c) In recent years, the number of puffins has decreased. Look at the statements below. A Oil pollution in the sea increases. B The number of seagulls decreases. C Fishing of sand eels increases. D Hunting puffins for food decreases. E The number of rats increases. Complete the table below by writing the letter of each statement, A to E, in the correct column. likely to increase the number of puffins likely to decrease the number of puffins [2] [Total: 6]

8 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 5 The diagram shows the cross-sections of two different types of blood vessel, A and B. A B (a) Describe how the structure of each blood vessel is related to its function. … … … … …[3] (b) There are blood vessels that supply blood to the heart muscle. These blood vessels can sometimes become blocked. This can lead to a heart attack. Explain how this blockage could lead to a heart attack. … … …[2]

9 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use (c) Leanne is a smoker. She reads the following information on the side of a cigarette packet. Smoking increases the risk of heart disease (i) This suggests there is a correlation between smoking and heart disease. Describe the correlation between smoking and heart disease. … …[1] (ii) A pressure group suggests that the label on the cigarette packet should be changed to Smoking will give you heart disease Suggest why this would be misleading. … … …[2] [Total: 8]

10 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 6 Some people may choose to undergo the process of pre-implantation genetic diagnosis (PGD). (a) Describe the process of PGD. … … …[2] (b) Lee and Margaret want a baby. They are both carriers of cystic fibrosis. Cystic fibrosis is caused by a recessive allele. They are advised to have their embryos tested using PGD. Explain why. … … …[2] (c) (i) It is possible to use PGD to make sure that a baby is a boy. In some countries, this is not allowed. Suggest one reason why. … …[1] (ii) Some people believe that PGD should not be carried out under any circumstances. Suggest one reason why. … …[1] [Total: 6]

11 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use 7 Microwave ovens use microwaves to heat food. (a) A microwave oven cooks food quickly. The microwaves do not harm the person using the oven. (i) Explain, using the correct scientific terms, how a microwave oven cooks food. … … …[2] (ii) State how a microwave oven is constructed to protect the user from microwave radiation. … …[1] (b) Mobile phones also use microwaves. Many people are concerned about the possible damage to the brain caused by the microwaves. Some people do not let their children have mobile phones until they are older. Other people think that young children are safer if they have mobile phones. Suggest one reason supporting each point of view. • reason for not having a mobile phone until the child is older … … • reason for young children having a mobile phone … …[2] [Total: 5]

12 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 8 This question is about tectonic plates and earthquakes. (a) The idea that the continents moved on the surface of the Earth was first suggested by Alfred Wegener. Scientists at the time did not accept these ideas. (i) Write down one piece of evidence supporting Wegener’s theory. … …[1] (ii) Give one reason why scientists in Wegener’s time did not accept his ideas. … …[1] (b) Magnetic measurements taken in the Atlantic Ocean in the 1950s showed a pattern of magnetic stripes on the seafloor, as shown below. normal magnetism mid-ocean ridge reversed magnetism (i) Explain how this pattern was produced. … … …[2] (ii) These results show that the seafloor is spreading. Explain how this finding supports Wegener’s theory that the continents are moving. … … …[1]

13 0608/04/M/J/12 © UCLES 2012 [Turn over For Examiner’s Use (c) The table shows the effect of different magnitude earthquakes and how often they happen. magnitude effect how often they happen in a typical year under 3 detected only by special equipment 1 300 000 3.0 – 3.9 just noticeable indoors 130 000 4.0 – 4.9 most people notice them – windows rattle 13 000 5.0 – 5.9 everyone notices them – slight damage to buildings 1 300 6.0 – 6.9 serious damage – bridges are twisted and walls break 130 7.0 – 7.9 great damage – most buildings collapse 13 greater than 8.0 total damage – widespread destruction 1 (i) Anita is describing an earthquake. Anita I was out in the garden and didn’t notice anything, but my sister was in the house and told me that all the pans on the kitchen shelves were shaking and rattling. Estimate the magnitude of the earthquake described by Anita. estimated magnitude = … [1] (ii) The following table shows how many earthquakes of magnitude greater than 7.0 happened in the first ten years of the 21st century. year 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 number of earthquakes of magnitude > 7.0 16 13 15 16 11 11 18 12 17 22 Discuss whether this shows that serious earthquakes are becoming more common. … … …[1] [Total: 7]

14 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use 9 This question is about radioactive decay. (a) Raoul tests the radiation given out by a radioactive material. He uses a radiation detector and sheets of paper, aluminium and thick lead. He shows that the radiation given out is beta radiation. Describe how he does this. … … …[2] (b) The diagram shows two different atoms. They are both atoms of the element helium. Each atom is made of three different particles. Complete the key to identify these particles. … … … particle name Key [1]

15 0608/04/M/J/12 © UCLES 2012 For Examiner’s Use (c) The two different forms of helium shown in (b) are both stable. Another form of helium, helium-6, is radioactive. The graph below shows how the radiation given out from a sample of helium-6 changes with time. 0.0 0 20 40 60 80 100 120 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 time in seconds number of counts per second (i) Before the graph was plotted, the background radiation count was removed from the readings so that the graph shows only the radiation from the helium-6. State where the background radiation comes from. …[1] (ii) Use the graph above to find the half life of helium-6. Show your working clearly on the graph. half life = … seconds [2] (iii) Another sample of helium-6 has an activity of 12 000 counts per second. Use the data above to estimate its activity after 4 seconds and explain how you get your answer. activity after 4 seconds = … counts per second explanation … …[2] [Total: 8]

16 0608/04/M/J/12 © UCLES 2012 Copyright Acknowledgements: Question 1 Photograph © David J Slater; Ref: B2AXOO; alamy.com. 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. BLANK PAGE

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2012 question paper for the guidance of teachers 0608 TWENTY FIRST CENTURY SCIENCE 0608/04 Paper 4 (Extended Written), maximum raw mark 60 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 May/June 2012 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 – May/June 2012 0608 04 © University of Cambridge International Examinations 2012 1 (a) identifying beta-carotene, lycopene and tartrazine as natural / others are synthesised (1); colouring from a natural / plant source do not cause hyperactivity / colourings that may cause hyperactivity are synthesised (1) [2] First mark is for sorting the data and the second is for the conclusion. ‘Those that do not cause hyperactivity are natural’ or the reverse gets both marks (b) (i) not certain that these colourings cause hyperactivity (1) ban their use until we know more / it is better to be safe than sorry (1) [2] (ii) carry out risk assessment / description of how additives could be tested (1) to find how much can be added to food safely / to set a safe limit (1) [2] Total: [6] 2 (a) there is a correlation between distance travelled and the number of asthma patients (1) as distance travelled increases number of asthma patients increases / correlation is positive (1) [2] if number of cars given (instead of distance), penalise once (b) a causal link / mechanism is needed / the graphs show correlation not cause (1) there may be other factors causing the rise in asthma patients (1) data does not give information on levels of particulates (1) [2] Any two allow air pollution comes from other sources (c) encourage people to use public transport / walk / cycle / encourage car sharing (1) design more efficient car engines / use electric cars / reduce car speed (1) have legal limits to emissions (1) [2] Any two Total: [6] 3 (a) (i) (285 + 279 + 282 + 289 + 284)/5 or 1419/5 (1) = 284 (1) [2] two marks for correct answer allow 283.8 allow one mark for 286 / 286.17 / 286.2 (no removal of outlier) (ii) mean for LDPE is not within the range for HDPE / mean for HDPE is not within the range for LDPE [1] do not allow ranges do not overlap (b) HDPE (no mark) because (tensile) strength is higher (1) so rope will not break easily (1) [2] no marks if LDPE chosen

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2012 0608 04 © University of Cambridge International Examinations 2012 (c) (i) HDPE has longer chain length / HDPE has (more) cross linking [1] allow reverse answer (ii) force of attraction between polymer chains is higher (1) more energy needed to separate the polymer chains (1) [2] Total: [8] 4 (a) Seagull Rats Stoats (any order) Puffins Sand Eels Plankton / Plants [2] one mark for organisms in correct places one mark for arrows pointing in correct direction (b) inter: any correct example of individuals from different species competing for food, e.g. stoats and rats competing for puffins intra: any correct example of individuals from same species competing for food, e.g. puffins competing with each other for sand eels [2] note interspecific competition will only take place between rats, stoats and seagulls note intra specific competition will take place at any stage in food chain (c) increase: B D decrease: A C E [2] all 5 correct = 2 marks 4 correct = 1 mark Total: [6] 5 (a) artery / A: small internal diameter (lumen) – blood maintained at high pressure (1) thick wall – prevents artery bursting under high pressure (1) more elastic tissue – allows arteries to push blood along / maintains high pressure (1) vein / B: large internal diameter (lumen) – allows large volume of blood to be carried (1) thin wall – blood not carried at high pressure / doesn’t need to be thick to withstand pressures (1) valves – prevent blood flowing backwards (1) [3] Max 3 marks mark can only be given when feature linked to function max 2 marks for each of artery and vein (b) less oxygen reaching the heart (1) heart tissue dies (1) [2]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2012 0608 04 © University of Cambridge International Examinations 2012 (c) (i) as the amount of smoking increases, the risk of heart disease also increases / alternative wording [1] amount of smoking could refer to number of cigarettes / length of time (ii) there is no guarantee that smoking will give you heart disease (1) there are other risk factors involved / example of other risk factors (1) all individual cases are different (1) [2] Total: [8] 6 (a) embryo produced outside the body / in laboratory / using IVF (1) genes of embryos tested (1) healthy embryo selected and replaced into mother (1) [2] any two (b) need both recessive alleles to get cystic fibrosis / each parent can pass on recessive allele (1) high risk of offspring (1 in 4) having cystic fibrosis (1) process would allow embryos with cystic fibrosis to be discarded (1) [2] any two points first marking point is for explaining ‘carrier’ (c) (i) not considered as important as selecting baby without genetic disease (1) imbalance of gender in the population (1) strain on resources / too expensive (1) [1] leads to gender selection for cultural reasons / morally incorrect / against religious teaching (ii) not ethical / morally incorrect / against religious beliefs / involves killing embryos (1) [1] Total: [6] 7 (a) (i) food absorbs microwaves (1); molecules (of water) in food vibrate (1); vibration heats food (1) [2] Any 2 (ii) metal walls / screen / door (to reflect back microwaves) [1] reject glass (b) child’s brain developing / child has thinner skull, so more at risk (1); any named factor for having phone, e.g. ability to ring home in emergency (1) [2] Allow any statement of precautionary principle for first point insufficient evidence of harm to young children Total: [5] 8 (a) (i) similar fossils (1); fit of continents (1); similar rock (layers) (1) [1] Any 1

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2012 0608 04 © University of Cambridge International Examinations 2012 (ii) too different from own ideas (1); Wegener was outsider / not scientist (1); there were simpler explanations (1); no mechanism / no evidence at the time(1) [1] Any 1 (b) (i) magma erupts / spreads and solidifies (1); earth’s magnetism recorded in rock (1); changes in Earth’s field with time (1); (symmetrical) pattern shows changes (1) [2] Any 2 (ii) provides a mechanism for movement of continents / shows how continents move [1] (c) (i) allow anything between 4.0 and 4.9 [1] (ii) no, because random variation present and no definite increasing pattern in number each year [1] Total: [7] 9 (a) count (for same time) with each absorber (1); passes through paper and aluminium but not lead (1) [2] ignore any reference to background radiation (b) neutrons protons electrons [1] (c) (i) (radioactive materials in the) environment / rocks / ground / from space [1] (ii) reading taken at 60 c/s (1); 0.8 s (1) [2] both marks for correct answer (iii) 400 (counts per second) (1); this is five half lives / 5 × 0.8 = 4s / count of 120 falls to 4 and 12000 is 100× more so 4 × 4 = 400 (1) [2] Total: [8]