0610_s03_ms_1+2+3+5+6

w w w e tr .X m ap eP s er om .c JUNE 2003 INTERNATIONAL GCSE MARK SCHEME MAXIMUM MARK: 40 SYLLABUS/COMPONENT: 0610/01 BIOLOGY Paper 1 (Multiple Choice) Page 1 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 1 Question Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Key B A B D B A D A A B C D C B C A D C C D Question Number 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 Key C D D C D D C B D B A C C C C D A A B A TOTAL 40 © University of Cambridge Local Examinations Syndicate 2003 JUNE 2003 INTERNATIONAL GCSE MARK SCHEME MAXIMUM MARK: 70 SYLLABUS/COMPONENT: 0610/02 BIOLOGY Paper 2 (Core) release of heat from or use of oxygen for respiration.Page 1 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 1 (a) excretion. in sealed container. carbon dioxide released indicates respiration. Credit annotated diagrams Any four – 1 mark each [4] Total [7] © University of Cambridge Local Examinations Syndicate 2003 . growth. look for limewater to go cloudy/milky/white/hydrogen carbonate to go yellow. movement. Apply pattern of mark scheme to alternative approaches e.feeding [3] (b) put mud in muslin bag/equivalent – workable apparatus.locomotion ignore . nutrition. suspend over limewater/calcium hydroxide solution/hydrogencarbonate/ bicarbonate indicator.g. Accept descriptions Any three – 1 mark each ignore . reproduction. incubate/leave for 12+ hours. reference to use of control. sensitivity/irritability. animals feed on/collect fruits from one region around tree. Any one – 1 mark ignore . Any feature plus explanation – 1 mark each [2] (iii) no smell/scent. Y – anther/stamen. stigma feathery. [2] (ii) small/insignificant “petals”/flowers “open”. do not prevent wind access to anthers/stigma/pollen. [1] (ii) most fruit found to north and east. inconspicuous shape/size of flower/petals. other valid biological suggestions. distribution of branches on tree. stigma hangs outside flower/petals.Page 2 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 2 (a) (i) X – stigma/carpel.human intervention. trap/filter pollen (from air). no nectar/nectary. no bright colours of petals/flowers/coloured green. stamens/anthers hang outside of flower/petals. Also features listed in (ii) above but not given in candidate’s response to (ii) Any two – 1 mark each [2] (b) (i) southwest. to catch pollen (in the wind). large quantities/smaller size pollen. [1] Total [9] © University of Cambridge Local Examinations Syndicate 2003 . to release pollen into wind/air. apply error carried forward [1] (iii) distribution of fruit on branches. dry/dusty pollen. [1] (ii) D/(ii) alongside a relevant arrow. Ignore . Any two – 1 mark each [2] (ii) less (leaves to) transpire/evaporation of water/evapotranspiration. less water v/water vapour in air/less rainfall. [1] (iii) P/(iii) alongside a relevant arrow. [1] If in any section more than one label is given all of that label must be correct (b) (i) less/no (trees/leaves) to photosynthesise. Any two – 1 mark each [2] Total [8] © University of Cambridge Local Examinations Syndicate 2003 . [1] (iv) R/(iv) alongside a relevant arrow.refs to floods/droughts/erosion/desertification.Page 3 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 3 (a) (i) C/(i) alongside a relevant arrow. more carbon dioxide in air/less removed from air. less roots/plants to absorb water (from deep layers). no/less (leaves/wood) to decay. [2] (ii) movement of water (molecules). [2] (c) (i) movement of molecules/particles/ions.Page 4 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 4 (a) (i) A – nucleus/nuclear membrane.hair reject . etc.trap bacteria/dust. [2] Total [11] © University of Cambridge Local Examinations Syndicate 2003 . [2] (ii) label C clearly linked to a cell membrane in each cell. to move mucus. ignore . down concentration gradient/from higher to lower concentration. transport oxygen. [2] Credit valid references to goblet cells and function of producing mucus (ii) has haemoglobin/no nucleus/biconcave. across/through partially/semi/differentially/selectively permeable membrane. B – cytoplasm. [1] (b) (i) has cilia (on one surface/end of cell). gametes.Page 5 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 5 (a) mitosis. [5] (b) use of correct symbols/X and Y. diploid. meiosis. parent genotype wrong – max 3 Any four – 1 mark each [4] Total [9] © University of Cambridge Local Examinations Syndicate 2003 . phenotypes for both sexes identified. offspring genotypes shown. gamete genotypes shown. haploid. parent genotypes shown. [1] Total [7] © University of Cambridge Local Examinations Syndicate 2003 . 2nd left box to top right box. [1] (iv) label to pancreas. [3] (b) (i) label to colon/large intestine.Page 6 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 6 (a) top left box to 2nd right box. [1] (ii) label to liver. reject . bottom left box to bottom right box.gall bladder [1] (iii) label to liver. reject .small intestine. double vision.signals unqualified/messages [4] (b) more/too much light enters/reaches retina.Page 7 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 7 (a) A – refracts/bends light rays/lets light enter eye. ignore .accommodation/change in shape C – controls light entering (inner) eye/reaching retina/lens. [2] Total [6] © University of Cambridge Local Examinations Syndicate 2003 . ignore . ignore .change in pupil D – changes light into/generates nerve/electrical impulses.protection B – focuses light rays/image on to the retina/fovea. dazzles person/causes blurred vision/damages retina. ignore . ignore . water moves/passes/is drawn up/ref to transpiration stream. from leaves/through stomata to atmosphere. (dye) dissolved/carried in water.Page 8 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 8 (a) (translocation) is movement of soluble materials/sugars/amino acids. down concentration gradient. from supply to demand/clearly identified example. Any four – 1 mark each [4] (b) leaves lose water. through xylem/vessels. Any four – 1 mark each [4] Total [8] © University of Cambridge Local Examinations Syndicate 2003 . (transpiration) is diffusion/loss of water vapour/evaporation of water. in phloem. up stem/leaf stalk. ignore .decomposers/saprophytes [1] (ii) heat/thermal (energy). ignore . ignore . [1] (c) energy is not passed back to the sun/grass/producer/ not recycled/OWTTE. [1] Total [5] © University of Cambridge Local Examinations Syndicate 2003 .potential [1] (b) (i) bacteria/fungi.solar [1] (ii) chemical (energy).Page 9 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 2 9 (a) (i) light/sunlight (energy). JUNE 2003 INTERNATIONAL GCSE MARK SCHEME MAXIMUM MARK: 70 SYLLABUS/COMPONENT: 0610/03 BIOLOGY Paper 3 (Extended) . 4 (d) (i) ref. ref. (iii) suitable organ named. ureter.Page 1 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 1 (a) one mark for each part (drawn) and labelled correctly: renal artery. blood passes along + dialysis tubing AW/visking tubing/cellulose or cellophane tubing. ref.’ max. Reject ‘waste products unqual.g. salts or minerals or named salts. (ONLY CREDIT ONCE) ref. urethra. to maintaining level of named substance in blood. to bubble trap/counter flow. to blood enters machine from patient AW. viii. ‘cleaned' blood returns + to patient's circulation/body AW. to pump.’/‘ions unqual. one mark for quality of drawing. to mechanism for maintaining constant level. (ONLY CREDIT ONCE) max. to tubing AW being semi-permeable/selectively permeable/ acting as a filter AW. as blood. v. e. waste materials/excess materials + pass from blood. ii. x. ref. urea. ref. iii. 2 2 3 max 18 © University of Cambridge Local Examinations Syndicate 2003 . iv. (ii) ref. MAX. ref. named substance levels maintained. to diffusion. containing + some salts/glucose/no urea. vii. filtration/reabsorption/osmosis/diffusion. 2 FOR LABELLING "STUMPS" ONLY 4 (b) water. P. to fluid has same O. ref. Allow nitrogenous waste uric acid. to surrounding liquid. x. ref. ix. to internal environment. method outlined. 3 (c) i. vi. Allow vitamins hormones. maintained (at constant level)/regulated/balanced. ref. to being bad for health/has side effects unqual. named. 2 (b) (i) 12 (%). use other suitable. source of fluoride. iii. (ii) or (iii) (i) fluoride (in water) reduces (the number of) decayed teeth in children. Reject refs. to allergies to fluoride. ref. ref. iv. (iii) i. (ii) AWARD 2 MARKS FOR CORRECT ANSWER. 1 2 (c) REJECT REF. to cost of fluoridation. 1 max 1 ref. max 1 max 8 © University of Cambridge Local Examinations Syndicate 2003 . to importance of personal choice/makes water impure. to fluoride flavouring water/refs. (ii) add fluoride to the drinking water in town B. EVEN WITHOUT WORKING 50 + 12 + 13 + 6 + 7. e. = 88 (%). advise children to use fluoride toothpaste. v.Page 2 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 2 (a) one mark for each column drawn and shaded correctly. browning of tooth enamel or possible cancer risk. ii. ref. TO FLUORINE ONCE in (i). to treatment of whole population when not all benefit. to side effects of too much fluoride.g. to possible use of local species for medicines. v. 2 (b) (i) Caulerpa grows at twice their rate AW. ref. to local fishing industry. 1 (iii) ref. 1 (d) (i) i. Reject ref. ref. to its ability to feed on Caulerpa. iv. 2 (c) ref. to primary consumer/(organism) that feeds on plants/producers. max 2 max 14 © University of Cambridge Local Examinations Syndicate 2003 . to effects on biodiversity. ref. ref. to introduction of disease. ref. vi. to importance of conservation. iv. vii. to chlorine being + dangerous/poisonous/damaging to other organisms/a pollutant. to extinction (of other organisms). to genus and species. ii. Reject refs. iii. ref. iii.Page 3 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 3 (a) involves giving the organism two names. ii. ref. to destabilization of the ecosystem. reduces competition between Caulerpa and local seaweeds. to disease/predation or shortage of + food/herbivores/sea urchins. causing their extinction AW. ref. allows other species to grow again. max 2 (iii) i. reduces population of Caulerpa. to O2 2 (ii) ref. max 2 (ii) ref. to possible effects on local food chains or food webs AW. to competition (for light/CO2/space for attachment/other plausible factor AW). v. ref. to no natural predators of the sea slug present AW. resulting in death/migration AW. it may eat other seaweeds as well. ref. to unbalancing + food chains/webs/ecosystem. ref. to pest unqual. ref. insects have 3 pairs of legs + arachnids have 4 pairs. viii. vi. iv. insects have antennae + arachnids do not. e. to jointed limbs AW. vi. to stages of development. iii. ecdysis/instars max 3 (ii) (DIFFERENCES) 1 MARK FOR TABLE. arachnids spin webs + insects do not. e.g.g. vii. ii. both have segmented body. table format with suitable headings. ref. Allow insects can be social + arachnids are not AW. iv. no backbone/ref. 4 FOR DIFFERENCES i. insects have 3 parts to the body + arachnids have 2 parts. larger wings. to survival of fittest/natural selection. v. both members of the arthropod group. suggestion for environmental change. vii. max 7 max 15 © University of Cambridge Local Examinations Syndicate 2003 . ix. favoured genes passed on to next generation AW. ref. v. ref. ref. variation/mutation + leads to differential survival AW. Accept ref. to benefit of change to the organism. MAX. ii. ref. max 5 (b) i. thicker cuticle. to simple eyes. food available. insects have compound eyes + arachnids do not/ref. to variation AW. insects have wings + arachnids do not. e. Allow refs to ability to fly iv. arachnids have chelicerae/pincer-like jaws + insects do not.Page 4 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 4 (a) (i) (SIMILARITIES) i. x. ii. to invertebrate. due to sexual reproduction/mating. iii. viii. named insect. to mutation. to exoskeleton. iii. suggested change to insect.g. v. temperature. ref. ref.g. used with cattle to increase milk production (linked to ix) xi. xvii. or ii. ref. to desertification/poor or thin soil. so there are fewer people to work the land/less land to grow crops on. xvi. ref. to increasing fruit yield AW. vi. x. flooding/drought. ref. to effect (only) on broad leaved plants (so monocot crops unaffected). xvi. to selling of food reserves to + settle national debt/maintain economy. to promote root and shoot formation/form a callus. xxi. to unsuitable climate/temperature/rainfall/ref. ix. ref. (linked to xi. ref. ii. tomato flowers to induce fruit production.g. (linked to vi. to increasing population requiring food. vii. to promotion of seed germination. xxii. xvii. ref. to BST (bovine somatotropin). xviii. to outmoded farm practices. poor soil/lack of inorganic ions or fertiliser. due to + deforestation/slash and burn. ref. to war/farm redistribution. next year's seeds eaten through need for food. ref. (linked to i. to pollution. ref. xv.) viii.) xv. cytokinin) in tissue culture. to urbanisation AW. happens even if pollination has not occurred. ref. so crops have less competition. to pest damage/disease (in crops or stored food). sprayed onto e. ref. ii. max 5 max 15 © University of Cambridge Local Examinations Syndicate 2003 . xii. vi. ref. to overgrazing. to production of seedless fruit.) v. to growth of + cash crops/monoculture/food for export (not suitable for local diet). or iii. max 10 (b) i. xxiv. xiii.) xiii. (linked to xiii. iii. to production of short plants (to resist wind damage). vii. ref. to natural disasters. xii. iii. used to increase meat production. xi. ref. so plants do not grow well. xix. e.Page 5 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 5 (a) ACCEPT OTHER PLAUSIBLE ANSWERS i. iv. forests destroyed + so nothing to hunt/no food to collect. iv. water used for other purposes/diversion of rivers/building dams/poor irrigation.g. to growth hormone/testosterone. viii. heat causes fresh produce to rot quickly AW. lack of suitable land to farm/ref. to use of hormones (e. to poor transport/distribution. ref. ref. xiv. to lack of money + to buy seeds/fertiliser/pesticides/machinery/ import food. to auxin. to delaying fruit production/ripening. ref. ref. so plants are killed/poor germination/no food for animals. so there is no-one to harvest crops/too dangerous to tend crops/no experienced farmers AW. v. ref. farmers poorly educated. (linked to viii. xxiii. xx. ref. ref. xiv. ix. ref.) x. to use of auxins in + weedkiller/herbicide. but allows exchange of materials between mother and fetus AW. to a pair of alleles. placenta keeps the blood of mother and fetus separate AW. ref. and different antibodies present in other blood AW. ii. Reject both dominant. due to presence of antigens on (the surface of) blood cells. ref. blood may + clump/clot/coagulate/agglutinate. IO IO = baby with blood group. once in which one is not dominant over the other AW. ACCEPT PUNNETT SQUARE IF LINES ARE USED TO LINK GAMETES AND F1. iii. mother = IA IO. IB I AI B I AI O I BI O I OI O IO vi. iii.Page 6 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 6 (a) i. ii. father = IB IO. iii. ii. since the blood types could be different AW. Allow both equally dominant iii. ii. IO (X) IB IO v. (gametes) IA 3 (b) Allow AO. Reject gene ref. 6 (c) (i) i. IA I A IB IO I A IO IB I O I O I O. to no clumping if donor blood group is group O. THEY MUST BE CORRECT i. IA i X I B I O. so both alleles have an effect in phenotype/heterozygous organism AW. iv. 3 max 15 © University of Cambridge Local Examinations Syndicate 2003 . max 3 (ii) i. (parents) IA IO iv. ref. using tail. ref. v. ii. ref. to swimming.Page 7 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 3 7 (a) MARK FIRST FIVE PARTS AND FUNCTIONS GIVEN ANY FIVE FROM: i. urethra + to pass sperm/semen + through penis. vi. iv. ref. iv. to passing through uterus/womb. to penis/ urethra + urine once. sperm nucleus and egg nucleus fuse. vi. max 4 (ii) i. ref. sperm penetrates egg membrane. to passing through cervix. ii. iii. ref. ref. ii. epididymis + to store/mature/move + sperm. ref. v. ref. max 3 max 15 © University of Cambridge Local Examinations Syndicate 2003 . ref. to mitochondria + energy. v. vi. v. penis + to insert sperm/semen + into vagina AW/ref. ref. to erectile tissue. to use of enzymes/acrosome. to use of condom/femidom (during sexual intercourse). testis + to make sperm/testosterone. to use of sterile needles (for injecting drugs)/don't share needles. to formation of zygote. avoiding contact with blood + example. iv. head of sperm enters egg. ref. enter an oviduct/fallopian tube. vii. ii. iii. ref. max 3 (c) i. vii. vii. prostate gland/seminal vesicles/cowper's gland + to produce seminal fluid AW. to maintaining one partner/not sleeping around. to abstinence from sexual intercourse. Reject refs to clean needles. to health education. vi. iii. to chemical sensor AW. scrotum + contain testes/to keep testes at lower temperature than that of body AW. iii. to zona pellucida. Allow ref. vas deferens/sperm duct + pass sperm from testis to urethra. to screening of blood for transfusions/blood checked for HIV. ref. 5 (b) (i) i. iv. JUNE 2003 INTERNATIONAL GCSE MARK SCHEME MAXIMUM MARK: 40 SYLLABUS/COMPONENT: 0610/05 BIOLOGY (Practical) . * time (table heading). not (0. each curve identified/use of key. half the paper min. not (0. * height/level/measurement (table heading). labels for axes including units. (time horizontal. records for both sets of dough S1 and S2. height vertical) (A) clock times c.0)). record of units mm/cm and min/(A) clock times. no obvious error. * clear lines. * plotting data for S1 (points visible. no obvious error. * use of ruled lines for columns and rows.0)). comment on rate of increase.Page 1 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 5 1 (a) * lose if no table. apply scheme as S1 trend. max 6 (c) curve for S1 rises (with time). * plotting data for S2 (points visible. If not as expected. plotting data using suitable scale. curve for S2 does not rise. S2 trend and suitable comment on rate of increase 3 suitable qualification © University of Cambridge Local Examinations Syndicate 2003 . readings taken at 5 min intervals. manipulation of data/recording increase or differences. max 5 (b) * lose if bar chart orientation of axes. Look at candidate's graph. sugar source of. living organism/fungus. main shell (if present)/pattern on dorsal surface (if shell absent). food/nutrition/energy/substrate.Page 2 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 5 (d) yeast is. shown. respiration. trapped/bubbles (remain in dough). sodium/potassium. rise stops as sugar runs out. carbon dioxide evolved. then (a few drops) copper sulphate (solution). equation (for anaerobic respiration). 2 (b) (i) Drawing – clear outline S4. foot/other soft parts. use label to help you identify presence of soft parts if drawing unclear or if snail in shell © University of Cambridge Local Examinations Syndicate 2003 . causes dough to rise. at least 5 cm in one direction. (protein) present. max 6 Total: 20 2 (a) (i) purple/mauve/lilac. reject precipitate/dark purple 2 (ii) add. without oxygen/anaerobic/fermentation. dough sinks and valid explanation. hydroxide (solution). rise stops as yeast killed by alcohol. texture.. idea of fair test. reject exoskeleton alone any soft part. other detail of fair test) reject control max 3 (d) (i) hard/rigid.. thermometer/temperature probe. record temp. (A) smooth qualified (A) like . shape. Apply scheme to any sensible plan.. (1 d.p. same procedure when investigating at different temps..Page 3 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 5 Labels – shell/dorsal surface pattern. place thermometer in contact with soft part of snail to record body temp. correct calculation of "drawing length ¸ specimen length".g. leave same time interval between measurements. hollow.. leave snails to adjust to surroundings before measuring. repeats. (e. colour/pattern. use. opening. dimensions.. contrast between inside and outside. max 2 © University of Cambridge Local Examinations Syndicate 2003 . (A) soft body reject eyes alone 6 (ii) length of drawing measured correctly (± 2 mm). of surrounding air. (A) time ref. use same number of snails. (A) several snails (A) area reject earth investigate at different temps.) ratio needs to be labelled 2 (c) Candidates may use snails "as they are" in this beaker or remove some/all of them. 2 (iii) support/protection ((A) shelter)/camouflage/muscle attachment.Page 4 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 5 (ii) effervescence/fizzing/AW. 1 Total: 20 © University of Cambridge Local Examinations Syndicate 2003 . shell is made of calcium carbonate. . JUNE 2003 INTERNATIONAL GCSE MARK SCHEME MAXIMUM MARK: 40 SYLLABUS/COMPONENT: 0610/06 BIOLOGY (Alternative to Practical) . time. key for separate date. humidity. [2] (v) Two from: 1. (accept enzyme. 2. Line B . cold) (b) (i) Graph: O S P K orientation of axes and label of axes plus units.rises and flattens. light. A more. improver. reasonable suggestion for role of substance X. Line C . comment on volume difference. [1] (iv) Two from: 1.rises steadily. pH.does not rise/rises slightly/at a constant level. plotting data A. max [5] (ii) Line A . amount of ingredients. AW) [2] Total 15 © University of Cambridge Local Examinations Syndicate 2003 . B. to production of carbon dioxide. [2 stages] [3] (iii) 80. carbon dioxide. 3. correct ref. catalyst. use of appropriate and even scale to fill half of the grid. A has yeast [and B has none]. 2. 3. C. substance X present in C [A has no X]. comment on rate difference/speeding up/faster.Page 1 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 6 1 (a) Two from: temperature or warmth or heat/[same type of] [amount of] yeast/type of flour/same size measuring cylinder/same mass or weight of dough/ [same quantity of] [type of] sugar [2] (ignore water [in q]. reading at eye level. but apply ecf for part (b) [1] (b) Three from: 1. 3. No ½ marks. a few seeds must be more than one seed for repetition idea. 2.Page 2 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 6 2 (a) 2 conditions = 1 mark.two sets one with and one without. idea of sample size many seeds. accept up to 3 weeks) max [3] Total 4 © University of Cambridge Local Examinations Syndicate 2003 . same species AW) 4. identification of one workable condition from (a) for investigation . some common factor of treatment between the two sets [with and without the condition] under investigation. left to grow for same time period. (equal watering. oxygen. (if stated minimum 1 + days. equal number of seeds. warmth [correct/suitable temperature/10 to 30°C if specified]. Labels – 2 from: Tentacles. actual size calculation is correct stated as . correct proportions.. shell [dorsal/visceral shell or hump]. eye [to be located at the end of the larger tentacles]. (ignore reference to negative features) [4] (ii) Magnification: Check measurements given are those transcribed into the formula drawing size. foot [qualified].. unsegmented body.1) max [2] (iii) Similarity – one from: both have tentacles/eyes/same head/shell. Difference – one from: A has no large external shell and B has/shell has different shape or comment on shape.Page 3 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 6 3 (a) (i) Drawing: clear outline.x 1+ (this must be more than 1 if drawings is as large as fig 3. AW [2] (iv) mollusc: [1] Total: 9 © University of Cambridge Local Examinations Syndicate 2003 .. for design of experiment: [2] 1. 10 ¸ 5 = 2cm3.heat shield. (iv) Two from. [1] (ii) photosynthesis. additional feature of design – (same time period for comparison of results/eliminate background light. carbon dioxide by adding hydrogen carbonate/AW) 3.so maybe dimmer or less light but must have detail of how this is to be achieved/distances away from light bulb/AW) 2. method for setting up different light intensities.Page 4 Mark Scheme IGCSE EXAMINATIONS – JUNE 2003 Syllabus 0610 Paper 6 4 (a) (i) introduce a glowing splint/spill (do not award for match will burn/candles lighting/splints that are already burning) addition of pyrogallol. describe how to control a factor that may alter rate over a certain time (temperature . [1] (iii) 10 cm 3 . (bright light in introduction . carry out investigation in a darkened room/replicates/ repetition/same piece of pondweed/recovery time between sets of measurements AW) max [2] (b) (i) (ii) (iii) Colour purple [1] red/orange [1] yellow [1] Explanation carbon dioxide used up/ photosynthesis [1] balance [between photosynthesis and respiration] [1] respiration of 3 water shrimps/ produce carbon dioxide [1] Total: 12 © University of Cambridge Local Examinations Syndicate 2003 . Grade A* does not exist at the level of an individual component. The threshold (minimum mark) for D is set halfway between those for Grades C and E. .Grade thresholds taken for Syllabus 0610 (Biology) in the June 2003 examination. maximum mark available Component 1 Component 2 Component 3 Component 5 Component 6 40 70 70 40 40 minimum mark required for grade: A 48 35 32 C 29 37 33 29 24 E 24 25 22 18 F 20 19 20 15 The threshold (minimum mark) for B is set halfway between those for Grades A and C. The threshold (minimum mark) for G is set as many marks below the F threshold as the E threshold is above it.