BIOLOGY 5090/11. Published

Transcription

1 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/11 Paper 1 Multiple Choice May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 2 printed pages. UCLES 2016 [Turn over

2 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Number Key Question Number Key 1 B 21 A 2 C 22 D 3 A 23 A 4 D 24 D 5 C 25 B 6 C 26 A 7 C 27 C 8 D 28 D 9 C 29 C 10 B 30 D 11 A 31 B 12 A 32 C 13 D 33 B 14 C 34 B 15 B 35 C 16 D 36 B 17 C 37 C 18 B 38 A 19 B 39 D 20 C 40 A

3 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/12 Paper 1 Multiple Choice May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 2 printed pages. UCLES 2016 [Turn over

4 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Number Key Question Number Key 1 A 21 A 2 C 22 D 3 B 23 D 4 C 24 D 5 B 25 B 6 A 26 D 7 C 27 C 8 B 28 B 9 A 29 C 10 B 30 B 11 A 31 C 12 C 32 A 13 D 33 C 14 C 34 C 15 B 35 C 16 B 36 D 17 C 37 A 18 D 38 B 19 A 39 B 20 D 40 A

5 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/21 Paper 2 Theory May/June 2016 MARK SCHEME Maximum Mark: 80 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 12 printed pages. UCLES 2016 [Turn over

6 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark Question Expected Answer Additional Guidance Mark 1 (a) (i) Label line X on xylem on transverse section of root ; [1] (ii) (iii) vascular bundle drawn towards outside of transverse section of stem ; vascular bundle divided into two sections ; three or more vascular bundles drawn ; label line P drawn in correct location (outer side of vascular bundle) ; [max 2] [1] (b) translocation ; [max 3] transport ; dissolved / in solution ; sugar(s) / sucrose / products of photosynthesis ; amino acids ; reference from source + to sink / leaves to roots AW ; [Total: 7]

7 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 2 (a) radicle / root ; [2] (b) stage A: testa / seed coat ; decreases ; stage B: decreases ; explanation for A / B: food store used ; reference to respiration ; reference to enzyme / named enzyme action ; stage C: increases ; (c) oxygen ; explanation for C: reference to photosynthesis ; reference to production of named food compound ; reference to more cells made / tissue growth ; reference to respiration ; energy + for growth ; maximum 3 marks for A / B and maximum 3 marks for C [max 6] [max 4] suitable / correct temperature ; reference to enzyme ; breaks down food store AW ; [Total: 12]

8 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 3 (a) diagram G: amylase ; [6] (b) mouth / small intestine / duodenum ; diagram H: small intestine / duodenum ; fat / lipid / oil ; fatty acid (s) ; glycerol ; reference to absorption / diffusion ; villi ; capillary ; blood / plasma ; reference to hepatic portal vein ; [max 4] [Total: 10]

9 Page 5 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 4 (a) (i) in nucleus (human) / within nuclear membrane ORA ; [max 3] in cytoplasm (bacteria) ; thread + plasmid(s) (bacteria) ; correct reference to chromosomes AW ; genes / chromosomes paired (human) ; (ii) (cell) wall ; [2] (cell) membrane ; (iii) type: asexual / binary fission / mitosis ; [3] explanation: genetically + identical (cells produced) OR clones ; all capable of producing insulin / same product ; A to produce insulin in large quantities / to produce a large number of bacteria / produce bacteria quickly (iv) diabetes ; [1] (v) fermenter ; A bioreactor [1]

10 Page 6 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark (b) potential advantages: increased yield / more profitable / grow quicker / reduce famine AW ; Max 3 marks for each of advantages / dangers. [4] able to grow in environmental extremes / grow in new areas ; more predictable results than selective breeding / more certain ; able to transfer (beneficial) genes / features between species ; nutritionally improved / visually improved / desirable outcome e.g. uniform shape ; disease / pest resistance ; potential dangers: risk of genetic spread to other species ; may be patented / costs too much ; possible (unknown) risk to health of other species ; possible (unknown) risk to genes of other species ; [Total: 14]

11 Page 7 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 5 (a) mosquito / Anopheles ; [1] (b) (i) drain swamps / prevent stagnation of water AW ; [max 2] add oil on water ; reference to biological control / fish or bacteria into ponds ; release irradiated males ; (ii) (resistant) reproduce ; A ORA for each marking point [max 4] reference to (resistant) allele / gene ; inherited / passed on ; reference to repetition over many generations ; (resistant) become more common ; reference to evolution ; [Total: 7]

12 Page 8 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 6 (a) (i) stomach ; [1] (ii) enzyme and substrate are lock and key ; [max 6] reference to optimum ph / (hydrochloric) acid (in stomach) ; active site ; complementary AW ; substrate ; if ph changes / alkaline ; enzyme denatured / changes shape AW ; (substrate) no longer fits ; (b) hydrogen ; [3] oxygen ; nitrogen ; [Total: 10]

13 Page 9 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 7 (a) fix / convert / change / turn (nitrogen in air) ; [max 5] (b) reference to lightning ; reference to bacteria ; legumes (peas / beans) / root nodules ; to ammonium ; to nitrates ; (nitrates) absorbed + by plants ; reference to amino acids (in either plants or animals) ; plants + eaten by animals ; protein digested (in animals) ; production of crops: increases / increased yield ; (due to) improved growth ; increased profit / AW ; environment: reference to positive effect on environment e.g. more photosynthesis reduces CO 2 / increases O 2 / more wild plants for insects ; growth of weeds ; leaching (into water sources) AW ; eutrophication or process described ; death of aquatic life ; possible contamination / pollution of (drinking) water ; [max 5] [Total: 10]

14 Page 10 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 8 (a) spinal cord ; [2] nerves / neurones ; named receptor / sense organ ; (b) R + medulla ; control of heart rate / breathing / involuntary actions ; relay of impulses between brain and spinal cord ; S + pituitary gland ; secretes / releases hormone(s) ; example of named hormone released + correct function ; T + cerebrum / cerebral hemispheres ; voluntary movement or example of ; thought / memory / any other acceptable function ; U + cerebellum ; coordination of movement ; maintenance of posture / balance ; A functions only if linked to correct named part of the brain e.g. TSH released which stimulates the thyroid gland to secrete thyroxine. [max 8] [Total: 10]

15 Page 11 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark 9 (a) externally administered ; [max 3] substance / chemical ; (that) modifies / affects / changes ; (the) chemical reactions (in the body) ; (b) (i) nicotine ; [max 5] addictive ; carbon monoxide ; reduced oxygen carrying capacity of blood ; reference to underweight babies AW ; tar ; cough / emphysema / bronchitis ; explanation of mechanism of one of the above e.g. cilia damaged / alveoli damaged / mucous lining blocked by tar ; correctly named cancer (e.g. lung / throat) ; reference to cardiovascular disease / increases blood pressure ;

16 Page 12 Mark Scheme Syllabus Paper Cambridge O Level May/June Question Expected Answer Additional Guidance Mark (ii) passive smoking or described e.g. effect on asthmatics / concerns around smoking near children / pregnant mothers ; reference to unpleasant odour / clothes smell ; reference to high cost ; [max 2] [Total: 10]

17 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/22 Paper 2 Theory May/June 2016 MARK SCHEME Maximum Mark: 80 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 10 printed pages. UCLES 2016 [Turn over

18 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark 1 (a) (i) sepals / calyx ; petals / corolla ; nectaries ; [max 2] (ii) type of pollination: self / wind ; [1] reason for wind: exposed / large + stamens / anthers ; reason for self: position of anthers relative to stigma / carpel ; reason for either : no petals / nectaries to attract insects ; [max 1] (b) (i) seed / cotyledon ; [1] (ii) bird / animal / herbivore ; sweet / sugary / coloured (skin) / juicy / succulent / taste / smell ; eaten / consumed / food ; spits out or drops / undigested / passes out with faeces ; R reference to excretion at a distance from parent plant / elsewhere AW ; [max 3] (c) (i) yeast / fungus ; R bacterium [1]

19 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June (ii) sugar (or named) / correct formula ; fermenter/ fermentation / anaerobic respiration (or description of) ; A sugar is broken down in the absence of oxygen reference to suitable temperature / warmth ; reference to enzymes ; [max 3] [Total 12] 2 (a) C / D / E ; C / D ; F ; E ; [4] (b) (i) heroin / alcohol / nicotine / named addictive drug ; [1] (ii) Ig reference to named drug / substance (e.g. CO, tar) mother s blood ; diffusion ; across or through placenta ; fetus / baby / embryo + blood ; umbilical cord / umbilical vein ; R umbilical artery [max 4] [Total 9] 3 (a) (i) mineral salts / fibre / roughage ; [1] (ii) fat / lipid ; [1]

20 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) constituent: water ; reasons for importance: solvent / constituent of urine / reference to chemical reactions / constituent cells OR cyto-, protoplasm OR blood / temperature regulator OR sweating / transporter / osmoregulator AW / prevents dehydration / lubrication / prevents constipation ;; constituent: (named) vitamin ; reasons for importance: prevent deficiency disease AW / reference to correct specified benefit of any vitamin ;; [1] [max 2] [1] [max 2] (c) little or no starch in diet / cannot digest starch AW ; relies on sugar or named sugar AW ; (needs to) eat fruit / animals / fewer plants ; may rely on fat / protein (for energy) ; [max 2] [Total 10] 4 (a) process: photosynthesis ; [1] explanation: 1. leaves flat ; 2. face the sun / horizontal ; 3. large / maximum / increased + surface area ; 4. (for) trapping / absorbing / converting + light (energy) ; 5. (for) CO 2 absorption / reference to stomata ; 6. presence of chlorophyll / chloroplasts ; 7. reference to transparent cuticle / epidermis / thin leaves ; 8. reference to intercellular spaces / mesophyll cells ; 9. reference to veins to bring water / take away products ; [max 2]

21 Page 5 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) effect: reduces (transpiration) ; Ig wilting [1] explanation: stomata ; (mostly) on lower surface ; any two of: humidity build up / reduced diffusion gradient / reduced evaporation (rate) / reduced surface area / (stomata / guard cells) close ;; protection from breeze / wind ; [max 3] (c) (i) reduced light levels ; photosynthesis slowing down ; less O 2 produced / lost AW ; stomata closing / closed AW ; [max 2]

22 Page 6 Mark Scheme Syllabus Paper Cambridge O Level May/June (ii) reference to darkness / low light intensity ; photosynthesis stops ; O 2 used / absorbed / gained / uptake AW ; (for) respiration ; [max 2] [Total 11] 5 (a) diffusion into the alveoli (box 2) ; the diaphragm relaxes (box 4) ; the ribs fall (box 8) ; pressure in the thorax increases (box 9) ; (b) 1. any stated difference between inspired and expired % O 2 ; 2. O 2 used in respiration ; 3. Person J the most / more (than normal) O 2 absorbed / used ; 4. Person J - active / taking exercise / athlete / pregnant / high respiratory rate / high blood cell or red blood cell count AW ; 5. Person K moderate activity / normal ; 6. Person L low O 2 absorption / use ; 7. Person L (named) lung disease / anaemia / smoker / inactive / sleeping / elderly / dying / low respiratory rate / reference to low red blood cell count / carboxyhaemoglobin ; A any disease that would restrict O 2 uptake [4] [4] [Total 8]

23 Page 7 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) structure: 1. cell wall thick / cell membrane thin ; 2. cellulose in cell wall ; 3. fat / protein in cell membrane ; 4. cell wall surrounds OR protects cell membrane ORA ; function: 5. wall permeable + membrane semi-permeable AW ; 6. cell wall no control / cell membrane has control over what enters cell ; 7. cell wall involved in turgor / support / protection / shape / prevents bursting ; 8. osmosis (only) through membrane ; 9. active transport (only) through membrane ; [max 6] (b) 1. (cell) the unit of life AW ; 2. tissues are made up of cells AW ; 3. cells in tissues have common / specific function ; 4. organs are made up of tissues AW ; 5. working / combining together ; 6. one example each of a named cell identified as such + a named organ identified as such ; A for tissue examples including: blood, muscle, nervous, epithelial, connective, xylem, phloem, palisade, epidermis A for organ examples including: muscle, heart, leaf, flower, root, stem [max 3] [1] [Total 10]

24 Page 8 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) Each importance must be linked to a condition in order to score credit. 1. oxygen ; 2. for respiration / energy release ; 3. growth / mitosis / cell division ; 4. water ; 5. solvent / reference to chemical reaction / transport ; 6. to rupture / break / soften testa (seed coat) ; 7. reference to temperature qualified e.g. suitable / warm ; 8. for enzyme action ; 9. digestion AW + of food / named food (stores) ; 10. seed must be viable / alive / no longer dormant ; [max 6] (b) 1. amino acids / sucrose or sugar ; 2. as a result of photosynthesis ; 3. in or from leaves / source / storage organ of parent or parent clearly implied ; 4. in solution ; 5. translocated / in phloem ; 6. in veins / vascular bundles ; 7. functional reference to cotyledon / endosperm OR sink ; [max 4] [Total 10]

25 Page 9 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) 1. sterilised / aseptic technique ; 2. fermenter ; 3. bacterium / fungus / algae / named example ; 4. substrate / cultured medium or named / broth / any two chemicals in the medium ; 5. oxygen / air ; 6. bubbles / sparger / aerator / paddle / stirrer AW ; 7. temperature regulation / control / cooling jacket ; 8. ph ref ; 9. optimum or best for growth or reproduction of organism ; 10. filtration / collection / harvesting / separating (the product) ; 11. name / use of product e.g. mycoprotein / meat substitute / cattle feed ; [max 8] (b) 1. size reference / extremely small AW ; 2. reproduce only in living cells / pathogenic AW / parasitic ; 3. specific ; 4. may need to separate them from living tissue / difficult to isolate ; 9 (a) (i) 1. allele(s) ; 2. responsible for a character(istic) / trait ; 3. only one needs to be present / reference to heterozygote AW ; 4. for the character to appear / be expressed (in phenotype) AW ; 5. e.g. I A I O + group A / I B I O + group B / I A I B + dominant to I O ; A named viral disease A A, B, O instead of I A, I B, I O [max 2] [Total 10] [max 3] (ii) 1. two alleles ; 2. neither being recessive / (equally) dominant ; 3. both have an effect / are expressed / phenotype intermediate ; 4. reference to heterozygote AW ; 5. I A I B / AB ; [max 3]

26 Page 10 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) 1. number of chromosomes in a gamete is half those in a somatic or body cell ORA / one versus two sets of chromosomes ; 2. correct use of the terms haploid + diploid ; v. 23 ; 4. gametes / haploid cells are the result of meiosis / reduction division ; 5. somatic / body cells occur in / produced by mitosis ; 6. (diploid) number restored + at fertilisation ; 7. each parent has equal share in genotype of offspring AW ; A sex cell = gamete / one named gamete [max 4] [Total 10]

27 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/31 Paper 3 Practical Test May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 4 printed pages. UCLES 2016 [Turn over

28 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark 1 (a) (i) all boxes completed ; [4] no colour change in test-tube B ; colour change in test-tube A at both temperatures ; more rapid colour change at 35 C than at 25 C for test tube A ; (ii) use a thermometer ; A temperature probe [1] (iii) (iv) (v) suitable method of heating / add cold water / add ice ; to allow yeast / enzyme / contents of test-tube to adjust to temperature / equilibration / AW ; in tube B enzymes inactive / enzymes denatured / yeast dead / inactive ; in tube A enzymes active / working ; [1] [1] [3] (in tube A) at 35 C increased enzyme activity ORA ; A enzyme becomes active more quickly (at 35 C) / works faster / closer to optimum temperature

29 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) (c) (i) (prepare) solutions with different ph values / use of buffers / acid and alkali ; appropriate range of ph values (minimum 3 values) ; add (buffer) to yeast (suspension) ; use stated / equal volume(s) of yeast (suspension) / buffer solution / methylene blue ; kept at stated temperature ; record time taken for blue colour to disappear / colour change AW ; time on x-axis and concentration on y-axis, both axes fully labelled ; linear scale starting at 0 with more than ½ grid used on both axes ; all points plotted correctly ; smooth curve through all plotted points ; [max 5] [4] (ii) 6.2 ; g per dm 3 ; answer consistent with graph [2] [Total 21]

30 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) all five leaflets shown + drawing at least 90 mm wide ; [5] (b) lower two leaflets smaller than the other three ; outline drawn with clean lines, serrated margin indicated, no shading ; pointed tips to the leaflets ; realistic representation of veins ; shape: laurel elongated / long / oval ; oak irregular / nonuniform / lobes / indentations / AW ; edge: laurel smooth ; oak smooth / AW ; [4] (c) (i) appropriate line drawn on Fig. 2.1; [2] (ii) maximum with of leaf = 18 mm ; magnification = / correct formula stated ; ( ) 0.45 ; tolerance mm units required for mark A measurement from 2(c)(i) [2] [Total 13] 3 (a) (i) as cycling speed increases, breathing rate also increases / AW ; (ii) 1. more energy needed ; 2. more oxygen needed ; 3. more carbon dioxide produced ; 4. (CO 2 removed) at a faster rate ; 5. correct reference to respiration ; (b) (minute volume =) ; A uses more energy A uses more oxygen A lactic acid [1] [max 3] [2] = (cm 3 ) ; correct answer only gains 2 marks [Total 6]

31 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/32 Paper 3 Practical Test May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 4 printed pages. UCLES 2016 [Turn over

32 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark 1 (a) (i) all boxes completed ; [4] no colour change in test-tube B ; colour change in test-tube A at both temperatures ; more rapid colour change at 35 C than at 25 C for test tube A ; (ii) use a thermometer ; A temperature probe [1] (iii) (iv) (v) suitable method of heating / add cold water / add ice ; to allow yeast / enzyme / contents of test-tube to adjust to temperature / equilibration / AW ; in tube B enzymes inactive / enzymes denatured / yeast dead / inactive ; in tube A enzymes active / working ; [1] [1] [3] (in tube A) at 35 C increased enzyme activity ORA ; A enzyme becomes active more quickly (at 35 C) / works faster / closer to optimum temperature

33 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) (c) (i) (prepare) solutions with different ph values / use of buffers / acid and alkali ; appropriate range of ph values (minimum 3 values) ; add (buffer) to yeast (suspension) ; use stated / equal volume(s) of yeast (suspension) / buffer solution / methylene blue ; kept at stated temperature ; record time taken for blue colour to disappear / colour change AW ; time on x-axis and concentration on y-axis, both axes fully labelled ; linear scale starting at 0 with more than ½ grid used on both axes ; all points plotted correctly ; smooth curve through all plotted points ; [max 5] [4] (ii) 6.2 ; g per dm 3 ; answer consistent with graph [2] [Total 21]

34 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) all five leaflets shown + drawing at least 90 mm wide ; [5] (b) lower two leaflets smaller than the other three ; outline drawn with clean lines, serrated margin indicated, no shading ; pointed tips to the leaflets ; realistic representation of veins ; shape: laurel elongated / long / oval ; oak irregular / nonuniform / lobes / indentations / AW ; edge: laurel smooth ; oak smooth / AW ; [4] (c) (i) appropriate line drawn on Fig. 2.1; [2] (ii) maximum with of leaf = 18 mm ; magnification = / correct formula stated ; ( ) 0.45 ; tolerance mm units required for mark A measurement from 2(c)(i) [2] [Total 13] 3 (a) (i) as cycling speed increases, breathing rate also increases / AW ; (ii) 1. more energy needed ; 2. more oxygen needed ; 3. more carbon dioxide produced ; 4. (CO 2 removed) at a faster rate ; 5. correct reference to respiration ; (b) (minute volume =) ; A uses more energy A uses more oxygen A lactic acid [1] [max 3] [2] = (cm 3 ) ; correct answer only gains 2 marks [Total 6]

35 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/61 Paper 6 Alternative to Practical May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 5 printed pages. UCLES 2016 [Turn over

36 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark 1 (a) (i) use a thermometer ; A temperature probe [1] (ii) suitable method of heating / add cold water / add ice ; [1] (iii) to allow yeast / enzyme / contents of test-tube to adjust to temperature / equilibration / AW ; [1] (iv) in tube A at 25 C blue colour disappears / colour changes at 7 or 8 minutes / remains for 7 minutes ; [3] in tube A at 35 C blue colour disappears / colour changes at 4 or 5 minutes / remains for 4 minutes ; no colour change in tube B (at either temperature) ; (v) in tube B enzymes inactive / enzymes denatured / yeast dead / inactive ; [3] in tube A enzymes active / working ; (in tube A) at 35 C increased enzyme activity ORA ; (vi) repeat (at each temperature) + take mean AW ; A use of colorimeter (to detect colour change more precisely) [1]

37 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) (prepare) solutions with different ph values / use of buffers / acid and alkali ; appropriate range of ph values (minimum 3 values) ; add (buffer) to yeast (suspension) ; use stated / equal volume(s) of yeast (suspension) / buffer solution / methylene blue ; kept at stated temperature ; record time taken for blue colour to disappear / colour change AW ; [max 5] (c) (i) time on x-axis and concentration on y- axis, both axes fully labelled ; [4] linear scale starting at 0 with more than ½ grid used on both axes ; all points plotted correctly ; smooth curve through all plotted points ; (ii) 6.2 ; g per dm 3 ; answer consistent with graph [2] [Total 21]

38 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) all five leaflets shown + drawing at least 90 mm wide ; [5] (b) lower two leaflets smaller than the other three ; outline drawn with clean lines, serrated margin indicated, no shading ; pointed tips to the leaflets ; realistic representation of veins ; shape: laurel elongated / long / oval ; oak irregular / nonuniform / lobes / indentations / AW ; edge: laurel smooth ; oak smooth / AW ; [4] (c) (i) appropriate line drawn on Fig. 2.1 ; [2] maximum with of leaf = 18 mm ; (ii) magnification = / correct formula stated ; tolerance mm units required for mark A measurement from 2(c)(i) [2] ( ) 0.45 ; [Total 13]

39 Page 5 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) (i) as cycling speed increases, breathing rate also increases / AW ; (ii) 1. more energy needed ; 2. more oxygen needed ; 3. more carbon dioxide produced ; 4. (CO 2 removed) at a faster rate ; 5. correct reference to respiration ; (b) (minute volume =) ; A uses more energy A uses more oxygen A lactic acid [1] [3] [2] = (cm 3 ) ; correct answer only gains 2 marks [Total 6]

40 Cambridge International Examinations Cambridge Ordinary Level BIOLOGY 5090/62 Paper 6 Alternative to Practical May/June 2016 MARK SCHEME Maximum Mark: 40 Published 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 May/June 2016 series for most Cambridge IGCSE, Cambridge International A and AS Level components and some Cambridge O Level components. IGCSE is the registered trademark of Cambridge International Examinations. This document consists of 6 printed pages. UCLES 2016 [Turn over

41 Page 2 Mark Scheme Syllabus Paper Cambridge O Level May/June Mark schemes will use these abbreviations: ; separates marking points / alternatives () contents of brackets are not required but should be implied R reject A accept (for answers correctly cued by the question, or guidance for examiners) Ig ignore (for incorrect but irrelevant responses) AW alternative wording (where responses vary more than usual) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by candidate (grammatical variants excepted) max indicates the maximum number of marks that can be given + statements on both sides of the + are needed for that mark

42 Page 3 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) (i) 1. ruled border lines + column line(s) ; [4] 2. headings: number of spines + (at) 1 m + (at) 3 m ; 3. all data for 1 m and 3 m transferred to table ; 4. all entered data correctly ranked lowest to highest ; (ii) (at 1 m) 16 ; [2] (iii) (iv) (at 3 m) 14 ; 1. linear scale with both axes labelled (mean number of spines, height above ground / m) + bars centrally labelled 1 m and 3 m (above ground) ; 2. two bars of same width drawn with ruled lines + tallest bar at least half of grid high (50 mm) ; 3. both means plotted accurately ; leaves nearer ground / at 1m have more spines / ORA ; number of spines is more variable 1m above ground / ORA ; [3] [max 3] a comparative manipulation of data ; e.g. difference in mean number is 2, range of 12 spines for leaves 1 m above ground and range of 8 spines for leaves A not much difference / not statistically significant difference / more or less random ranges of data overlap / means are similar ; (v) larger sample of leaves ; take leaves from other holly trees ; take leaves from further up / down / different heights / specified heights ; A take more than 12 / larger number / repeat [2]

43 Page 4 Mark Scheme Syllabus Paper Cambridge O Level May/June (b) either: 1. remove epidermis / make impression (of both surfaces) ; 2. place (each) on a slide ; 3. use of a coverslip / stain / water ; 4. use of microscope ; 5. idea of counting number of stomata (in field of view / known area) on both surfaces ; or: 1. water (vapour) lost through stomata ; 2. cobalt chloride paper on both leaf surfaces ; 3. blue cobalt chloride paper turns pink (with water) ; 4. time to change colour measured ; 5. faster time = more stomata ; [max 4] [Total 18]

44 Page 5 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) use of water bath / other safety feature ; 1. blue + Benedict s solution ; A goggles, test-tube holder [1] [max 4] 2. heat ; 3. same length of time / temperature ; 4. equal volumes of Benedict s solution / milk used ; 5. colour changes observed + compared ; (b) (i) all centres of successive crosses joined with ruled lines ; [1] (ii) ph decreases / becomes more acid (ic) ; A there is an inverse relationship between ph and time [max 2] faster at first then more slowly ; appropriate manipulation of data ; e.g. overall decrease in ph of 1.05 / decrease of 0.6 in first two weeks (iii) 1. bacteria / enzymes / named example ; [3] 2. convert sugar / lactose / protein / fats ; 3. into lactic acid / amino acids / fatty acids ; [Total 11]

45 Page 6 Mark Scheme Syllabus Paper Cambridge O Level May/June (a) A humerus ; B ulna ; (b) 1. outline continuous and clean ; [2] [3] 2. length mm inclusive ; 3. proportions / detail approximately correct ; (c) (i) ; (ii) measurement from 3(c)(i) / 243 ; [1] [2] 0.4 ; (d) (i) hinge ; A synovial Ig elbow (ii) bending (of the arm) ; [1] [2] and straightening ; A flexion and extension for 2 marks movement in one plane / 2 dimensions / 180 ; [Total 11]