Science Stage 9 Paper 2 Cambridge Lower Secondary Progression Test Mark Scheme 3146_02_MS_8RP © UCLES 2022 2022 S9/02 Science Stage 9 Paper 2 Mark Scheme 2022 General guidelines on marking Many descriptive answers can be expressed in a variety of ways. Professional judgement can be used in these cases, providing it matches the marking points and further information in the mark scheme. Answers may have words spelt incorrectly. Credit is normally given for phonetically correct answers, unless the word has a scientifically different meaning. For example, where the answer should be antennae, credit will be given for antena but not for anthen (too close to anther). Only the science is being assessed, so answers do not need to be grammatically correct. Significant figures will be indicated in the question or in the mark scheme. Unless specified all marking points are independent. Annotations and abbreviations / or alternate responses for the same marking point ( ) brackets the words or units in brackets do not need to be stated, for example, (recycles or releases or provides) minerals = minerals scores the mark underline exact word is required Accept an acceptable response Do not accept indicates an incorrect response that would contradict another otherwise correct alternative Ignore indicates an irrelevant answer that is not creditworthy. Full marks can still be achieved even with answers that are ignored. Note provides extra information when necessary ecf error carried forward; marks are awarded if an incorrect response has been carried forward from earlier working provided the subsequent working is correct ora or reverse argument; for example, as mass increases, volume increases could be written as mass decreases, volume decreases © UCLES 2022 Page 2 of 10 © UCLES 2022 Page 3 of 10 leaving the blood without any toxic substance / (membrane) does not allow blood through the toxic substance goes through the (partially permeable) membrane urine is stored here before excretion from body bladder 1(c) urine travels through this tube to be stored ureter filters (the blood) blood enters excretory (renal) system renal artery kidney what happens part Answer urea Question Marks Science Stage 9 Paper 2 Mark Scheme 1(b) 1(a) S9/02 Accept the (partially permeable) membrane only lets the toxic substance through = 2 marks Accept the (partially permeable) membrane lets the toxic substance through but not the blood = 2 marks Accept urea for toxic substance Accept blood is purified 2 each correct answer = 1 mark 1 Accept (ultra)filtration 3 each correct answer = 1 mark Further Information 2022 attraction between positive and negative ions 801 °C 3(b)(ii) 3(b)(iii) Page 4 of 10 ionic / electrovalent 3(b)(i) © UCLES 2022 sodium (atom) loses an electron Answer Answer Marks Marks Science Stage 9 Paper 2 Mark Scheme 3(a) cancellation 2(b)(ii) increases stays the same reinforcement Question Question 2(b)(i) 2(a) S9/02 Accept any indication of the correct answer, e.g. ticking or underlining, but circling takes precedence 1 more than one answer circled = 0 marks 1 Accept electrostatic attraction between ions 1 1 Accept electron(s) lost Further Information 1 Accept destructive interference 1 Accept constructive interference 2 each correct answer = 1 mark Further Information 2022 (prediction) (the two large pieces of biscuit) will move (apart) 4(b)(ii) © UCLES 2022 4(c) 4(b)(iv) 4(b)(iii) (Earth’s) core 4(b)(i) Page 5 of 10 climate change / increase in global temperature / increase in carbon dioxide in atmosphere / increase in sulfur dioxide in atmosphere / (idea that) oxygen levels reduced position of volcanoes alignment of magnetic materials in the Earth's crust fossil record jigsaw appearance of continental coasts (idea that) earthquakes occur at plate boundaries (earthquakes) result from movement of plates (explanation) convection current (moves the biscuits/plates) (tectonic plates) are less dense than the mantle 4(a)(ii) Answer crust Question Marks Science Stage 9 Paper 2 Mark Scheme 4(a)(i) S9/02 Accept leads to an ice age with no reference to global warming in the answer 1 Accept blocks sunlight 2 each correct answer = 1 mark 2 each correct answer = 1 mark 2 each correct answer = 1 mark 1 1 Accept less dense than magma 1 Accept lithosphere Further Information 2022 36 38 gestation period in weeks 40 © UCLES 2022 increase sample size 2.4 34 2.8 5(b) birth mass in kg 3.2 3.6 Answer (birth mass is) decreased by smoking Question Page 6 of 10 42 key non-smokers smokers Marks Science Stage 9 Paper 2 Mark Scheme 5(a)(ii) 5(a)(i) S9/02 1 1 Accept as gestation period increases, birth mass increases more than one point circled = 0 marks 1 Accept other correct indications of the anomalous point but circling takes precedence Further Information 2022 Question © UCLES 2022 8(c) 8(b) 8(a) 7 Answer population Page 7 of 10 1 Accept reduced fecundity (without sperm) no fertilisation takes place 2 each correct answer = 1 mark Accept 23 is the haploid number for humans = 2 marks 2 each correct answer = 1 mark Further Information 3 each correct answer = 1 mark Further Information 1 Accept Rb but name takes precedence 1 1 Further Information Accept sperm not viable Marks Marks Marks (higher temperatures) reduce sperm production (idea that sperm cell has) half the number of chromosomes of a fertilised egg cell 23 decreases thermal evaporate Answer rubidium 6(c) Question any value in the range 550 to 650 (°C) 6(b) Answer any value in the range 105 to 200 (°C) Question Science Stage 9 Paper 2 Mark Scheme 6(a) S9/02 2022 Question © UCLES 2022 9(c) 9(b) 9(a) S9/02 Accept (hydrochloric acid) burns the skin/eyes hydrochloric acid is corrosive/harmful 2 each correct answer = 1 mark Accept more frequent collisions with powder 2 each correct answer = 1 mark Do not accept name of incorrect gas is lost/released Ignore water vapour is lost Accept a reading less than 102.34 g 2 each correct answer = 1 mark Further Information Ignore facemask Marks 2022 wear goggles/gloves Page 8 of 10 more collisions with powder / fewer collisions with lumps powder has a greater surface area / lumps have a smaller surface area as carbon dioxide/gas is lost/released (from the equipment) (reading on balance) gets less / decreases / reduces Answer Science Stage 9 Paper 2 Mark Scheme Question © UCLES 2022 10(b) 10(a)(ii) 10(a)(i) S9/02 (idea that) current divides/splits V Page 9 of 10 correct symbol for voltmeter connected in parallel with lamp e.g. A correct symbol for ammeter connected in series with cell and lamp e.g. Answer Marks Science Stage 9 Paper 2 Mark Scheme 1 1 1 Further Information 2022 Question © UCLES 2022 11(b) 11(a) S9/02 Page 10 of 10 add to water and record if they float or sink use objects of the same shape/size measure the density of a range of different plastic objects any two from objects with a density less than cooking oil or 0.9 g / cm3 will float objects with a density greater than cooking oil or 0.9 g / cm3 will sink any one from Answer Marks 2022 Accept ice will remain suspended as its density is the same as cooking oil Further Information 2 each correct answer = 1 mark 1 Science Stage 9 Paper 2 Mark Scheme