Weebly



Mark schemesQ1.(a) ????stinging hairs / can sting1(so) this harms herbivores / stops animals eating them1(so) less of the plant is removed / damaged1(b) ????clove (oil)1it has the largest areas with no bacteria growingallow largest inhibition zone or description of largest inhibition zone1(c) ????antibiotics were not tested1[6]Q2.(a) ????A1(b) ????D1(c) ????use the same type of plantorgive equal amount of water to each plantignore size of pot1(d) ????(advantage) more minerals1(disadvantage) cost / not free1[5]Q3.(a) ????to kill virusorto prevent virus spreading1(b) ????take (stem) cells from meristemortissue cultureallow take cuttings1(c) ????use Benedict’s solution1glucoses turns solution blue to orange1(d) ????Level 2 (3–4 marks):A detailed and coherent explanation is provided. The student makes logical links between clearly identified, relevant points that explain why plants with TMV have stunted growth.Level 1 (1–2 marks):Simple statements are made, but not precisely. The logic is unclear.0 marks:No relevant content.Indicative content?????????less photosynthesis because of lack of chlorophyll?????????therefore less glucose made?????????so?????????less energy released for growth?????????because glucose is needed for respiration?????????and / or?????????therefore less amino acids / proteins / cellulose for growth?????????because glucose is needed for making amino acids / proteins / cellulose4[8]Q4.(a)?????compare them to (pictures in) a gardening manual / website1send to laboratory (for testing)1(b)?????(nitrate) stunted growth1(magnesium) yellowing of leavesallow chlorosis1(c)?????(fertiliser S)has most nitrogen for good growthif no other marks awarded allow 1 mark for (fertiliser s) has more minerals than compost1(and) has high(est) potassium content for stronger roots1(it is also) cheaper than fertiliser T1(however) has less phosphate than fertiliser T (although more than compost) so flowers / fruit perhaps less important for the gardener1[8]Q5.(a)???? protein1(b)???? (i)??????(more) magnesium gives more growth / more leaves / more duckweedif converse must be clear that less magnesium gives less growth1(ii)?????A gave highest number of leaves / plants or more than othersit equals ’A’use of numbers must compare A with at least one otherorA gave most growth / most duckweed or more than othersallow faster / fastest / better / best growthallow more growth with nitrate / less growth without nitratedo not allow ‘no’ growth without nitrate(c)????(i)??????mark (c) as a wholesensible method:e.g. mass / weighingignore dry or freshallow other sensible method involving measuring eg length of roots – ignore ‘size’ of roots or measure roots unqualified1(ii)?????corresponding explanation:ignore accuracye.g. includes roots / includes whole plantorleaves vary in sizeor(length / mass / surface area given in c(i)) is a continuous variable1[5]Q6.(a)????less carbon dioxide used or higher carbon dioxide (concentration) in jardo not allow no carbon dioxide used or no change in carbon dioxide1because less photosynthesis or light was a limiting factordo not allow no photosynthesis1(b) ????magnesium / Mgdo not allow manganese / Mnallow iron / Feignore nitrates1[3]Q7.(a)???? photosynthesisdo not accept other additional processes1(b)?????(i)????? any three from, eg:ignore time / apparatus?????????mass of pondweedtype of pondweed = max 2accept amount / volume / length / sizeignore number / surface area of leaves / pondweed unqualified?????????volume of wateraccept amount?????????other reasonable features of the water?????????light intensityaccept distance between light source and tube / pondweed?????????light colouraccept light if neither colour nor intensity is given?????????carbon dioxide ?????????temperature?????????pH3(ii)?????any one idea from, eg:ignore reference to cost?????????how much oxygen they give off?????????is pondweed poisonous to fish?????????will fish eat pondweed?????????is pondweed harmful to environment?????????how long the pondweed lives?????????growth rate / size of pondweed?????????reference to appearance / aesthetics?????????availability1(c) ????magnesium / Mgaccept iron / Feignore ion and + or -ignore nitrate1[6]Q8.(a)?????? root1(b)?????(i)???? chlorophyll1(ii)???? absorbs / traps / takes in lightdo not accept attracts / solar energy /sunshine / sun1(for) photosynthesisaccept to make food / glucose / sugar/ biomass1(c)????1 mark per correct lineextra line from a mineral ion cancels the mark2[6]Q9.(a) ????(140 + 240 + 380 + 450 = ) 12101(b) ????the local people decided to farm cattle1a company starts growing plants for biofuels1(c) ????carbon dioxidein this order only1photosynthesis1(d) ????animals and birds migrate because there is less food1more habitats are destroyed1(e) ????any one from:?????????breeding programmes (for endangered species)?????????regeneration (programmes)?????????reintroduction of field margins / hedgerows?????????awareness raising with politicians / public?????????recycling1[8]Q10.(a) ????methane is producedignore bad smell1which is a greenhouse gas / causes global warming1(b) ????(9.80 / 0.20 = 49 therefore) 49:11(c) ????horse (manure)allow ecf from 11.2closest to 25:1 (ratio)1(d) ????Level 3 (5–6 marks):A detailed and coherent explanation is given, which logically links how carbon is released from dead leaves and how carbon is taken up by a plant then used in growth.Level 2 (3–4 marks):A description of how carbon is released from dead leaves and how carbon is taken upby a plant, with attempts at relevant explanation, but linking is not clear.Level 1 (1–2 marks):Simple statements are made, but no attempt to link to explanations.0 marks:No relevant content.Indicative contentstatements:?????????(carbon compounds in) dead leaves are broken down by microorganisms / decomposers / bacteria / fungi?????????photosynthesis uses carbon dioxideexplanations:?????????(microorganisms) respire?????????(and) release the carbon from the leaves as carbon dioxide?????????plants take in the carbon dioxide released to use in photosynthesis to produceglucoseuse of carbon in growth:?????????glucose produced in photosynthesis is used to make amino acids / proteins / cellulose?????????(which are) required for the growth of new leaves6(e) ????any three from:(storage conditions)?????????(at) higher temperature / hotter?????????(had) more oxygen?????????(had) more water / moisture?????????(contained) more microorganisms (that cause decay)allow reference to bacteria / fungi / mould3[13]Q11.(a)?????any two from:?????????idea of absorption of light / energy?????????transfer to chemical energyallow produce sugars / glucose / starch / carbohydrate / food / biomass?????????provides food / energy for animals / caterpillar?????????releases oxygen2(b)??????1(c)?????15(%)allow 1 mark for??with no answer or incorrect answerorallow 1 mark for 0.152(d)?????(i)?????any two from:?????????markings look like eyes / face / mouth of much larger animal?????????looks fierce / scary / dangerousallow it looks like a snake?????????to frighten blue tit / birdmax 1 if reference to camouflage2(ii)?????any two from:?????????sharp / long / big clawsignore strong?????????sharp / hooked beakignore strong / big?????????large wings or flies quicklyallow streamlined / aerodynamicignore powerful wings?????????good eyesight2[9]Q12.(a)?????(i)????reduced photosynthesisignore growthdo not allow need light for respiration1(ii)?????less food (for animals) or less oxygen (for animals)allow loss of habitat1(iii)?????any two from:accept 2 physical factors or 2 biological factors or one of each for full marksexamples of physical factors, eg?????????flooding?????????drought?????????ice age / temperature changeignore pollution?????????volcanic activityexamples of biological factors, eg?????????(new) predators (allow hunters / poachers)?????????(new) disease / named pathogen?????????competition for food?????????competition for mates?????????cyclical nature of speciation?????????isolation?????????lack of habitat or habitat changeIf no other answers given allow natural disaster / climate change / weather change / catastrophic event / environmental change for 1 mark2(b)?????(i)??????31(ii)?????fossilsignore bones, remains, fossil fuels1(c)?????(i)??????65 million years ago1(ii)?????17allow ecf1(iii)?????fossil record incompleteorsome fossils destroyedaccept not enough evidenceorcannot perform experiment to test1[9]Q13.Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.Level 3 (5–6 marks):A description of how the apparatus is used to measure the rate of photosynthesis at different light intensities is given.For full marks reference must be made to a control variableorrepeatsLevel 2 (3–4 marks):A description of how the apparatus is set upanda description of how photosynthesis can be measured.ora description of how light intensity is variedora control variable or any other relevant pointLevel 1 (1–2 marks):A partial description of how the apparatus is set upora description of how light is suppliedora simple description of how photosynthesis can be measured.ora control variable0 marks:No relevant content.examples of the points made in the response:?????????apparatus set up:– weed in water in beaker– light shining on beaker?????????method of varying the light intensity–eg changing distance of lamp from plant?????????method of controlling other variables– use same pond weed or same length of pond weed– temperature: water bath or heat screen– CO2?????????leave sufficient time at each new light intensity before measurements taken?????????method of measuring photosynthesis – eg counting bubbles of gas released or collecting gas and measuring volume in a syringe?????????measuring rate of photosynthesis by counting bubbles for set period of time?????????repetitionsextra information:allow information in the form of a diagram[6]Q14.(a)???? 6H2Oin the correct order1C6H12O61(b)???? (i)??????controldo not accept ‘control variable’allow:to show the effect of the organismsorto allow comparisonorto show the indicator doesn’t change on its own1(ii)?????snail respires1releases CO21(iii)????turns yellow1plant can't photosynthesise so CO2 not used up1but the snail (and plant) still respires so CO2 produced1[8]Q15.(a) ????(i)??????LHS = wateraccept H2Odo not accept H2O / H2O1RHS = oxygenaccept O2do not accept O / O2 / O21(ii)?????light / sunlightignore solar / sun / sunshinedo not allow thermal / heat1(iii)????chloroplastsallow chlorophyll1(b)???? (i)??????201(ii)?????any one from:?????????light (intensity)?????????temperature.1(c)???? (i)??????To increase the rate of growth of the tomato plants1(ii)?????Because it would cost more money than using 0.08%1Because it would not increase the rate of photosynthesis of the tomato plants any further1[9]Q16.(a) ????light is trapped / absorbed / usedextra answers cancel markignore solar / sunshine1by chlorophyll / chloroplastsif no other marks awarded, allow 1 mark for photosynthesis / equation for photosynthesis1(b)???? (to make) starch (for storage)ignore ‘for growth’ unqualifiedignore respiration1(to make) fat / oil (for storage)1(to make) amino acids / proteins / enzymes1(to make) cellulose / cell wallsallow for active transportallow any other correct, named organic substances (eg DNA / ATP / chlorophyll / hormone)if no named examples, allow ‘to make named cell structures’ for max. 1 mark1[6]Q17.(a)???? LHS = water1RHS = glucose1(b)???? any three from:?????????(measure) temperatureignore reference to fair test?????????to check that the temperature isn’t changing?????????rate of reaction changes with temperature?????????temperature is a variable that needs to be controlledallow lamp gives out heat3(c)???? (i)??????10correct answer = 2 marksallow 1 mark for: ??allow 1 mark for correct calculation without removal of anomalous result ie 152(ii)?????graph:allow ecf from (c)(i)label on y-axis as ‘number of bubbles per minute’1three points correct = 1 markallow ± 1 mmfour points correct = 2 marks2line of best fit = smooth curve1(iii)????as distance increases, rate decreases – proallow yes between 20 – 401but should be a straight line / but line curves – con / not quite proallow not between 10 – 20if line of best fit is straight line, allow idea of poor fit1(d)???? any four from:?????????make more profit / cost effective?????????raising temp. to 25 °C makes very little difference at 0.03% CO2?????????(at 20 °C) with CO2 at 0.1%, raises rate?????????(at 20 °C with CO2 at 0.1%) → >3x rate / rises from 5 to 17?????????although 25 °C → higher rate, cost of heating not economical?????????extra light does not increase rate / already max. rate with daylightaccept ref to profits c.f. costs must be favourable4[17]Q18.(a)???? (i)??????chloroplast1(ii)?????cell wall1(b)???? (i)??????osmosisaccept diffusion1(ii)?????cell wall (prevents bursting)1(c)???? (i)??????carbon dioxideallow correct formula1glucoseallow sugar / starch1(ii)?????any two from:?????????light sensitive spot detects light?????????tells flagellum to move towards light?????????more light = more photosynthesis2(d)???? (cell has) larger SA:volume ratio1short (diffusion) distanceallow correct description1(diffusion) via cell membrane is sufficient / good enoughorflow of water maintains concentration gradient1[11]Q19.(a)???? (i)??????traps light (energy)allow uses light / converts light energy to chemical energy1for photosynthesis / for making sugar / starch / carbohydratesignore foodallow organic molecules1(ii)?????dodder takes sugar / glucose / sucrose from phloem / dodder cannot make its own glucose / carbohydrateorphloem has sugar / glucose / sucroseaccept amino acids / fatty acids / other small organic moleculeignore takes food / minerals / water / nutrients1(iii)????any one from:?????????not enough sugar / nutrients to grow / respireaccept not enough food to grow / respire?????????might strangle / restrict growth by squeezing stem tightly?????????may damage stem tissues by growing into it?????????may smother leaves / block light so less photosynthesis / less growth1(b)???? Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also refer to the information on page 5, and apply a ‘best-fit’ approach to the marking.0 marksNo relevant content.Level 1 (1 – 2 marks)Description and explanation of an adaptation which only involves hooks and / or suckers.Level 2 (3 – 4 marks)Description and explanation of adaptations including hooks and / or suckers with any other adaptation or explanation.Level 3 (5 – 6 marks)Description of most correct adaptations and explanations.Examples of biology points made in the response:?????????hooks – for holding on / not being detached?????????suckers – for holding on / not being detached?????????flattened / large surface area – absorption of (large amounts of) food?????????no gut – not needed as host digests food?????????thick cuticle – protection from host’s enzymes / so not digested?????????large number of eggs – increased chance of infecting new hostallow hermaphrodite and self-fertilising – likely to be just one worm per hostinternal fertilisation – gametes not digested6[10]Q20.(a)???? (i)??????in the direction of the force of gravity1(ii)?????against the force of gravity1(b)???? (i)??????diagram completed to show stem bending / leaning towards the windowthe bend / lean can be at / from any point above pot levelignore any leaves1(ii)?????more light (for leaves)ignore heat1more photosynthesis / biomass / glucoseref to ‘more’ needed once only, eg ‘more light for photosynthesis’ = 2 marksif no other marks given allow 1 mark for ‘to get light for photosynthesis’1[5]Q21.(a)???? chlorophyll is needed for photosynthesis1light is needed for photosynthesis1(b)???? increases1levels off / reaches a maximum / remains constant / stays the same / plateausdo not allow stops / stationary / peaksallow stops increasing1goes up to / reaches a maximum / levels off at (a rate of) 200 (arbitrary units)orlevels off at 225 – 240 (light units)ignore references to other numerical values1(c)???? (i)??????higher light intensity does not increase rate of photosynthesisaccept the graph stays level (above this value)allow stops increasingallow the rate of photosynthesis stays the same (above this value)1(ii)?????any two from:?????????carbon dioxide (concentration)?????????temperature / heat?????????(amount of) chlorophyll / chloroplastsallow waterallow ions / nutrientsignore ref to surface area of the leaf2[8]Q22.Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also apply a ‘best-fit’ approach to the marking.0 marksNo relevant contentLevel 1 (1 – 2 marks)There is at least one reason for deforestationoran attempt at a description of at least one way deforestation is affecting the atmosphere.Level 2 (3 – 4 marks)There is at least one reason for deforestationanda description of the way deforestation is affecting one gas in the atmosphereorthe process that causes an effect.Level 3 (5 – 6 marks)There are reasons for deforestationanda clear description of the way deforestation is affecting one gas in the atmosphereandthe process that causes this.examples of the points made in the responseReasons for deforestation?????????timber for construction / furniture / boat building / paper production?????????growing plants for biofuels for motor fuel / aviation / lawnmowers?????????use of wood as a fuel?????????land for building or agriculture to provide food, such as rice fields and cattle ranchingEffects of deforestation?????????increase in carbon dioxide in atmospheredue to burningdue to activities of microbesless carbon dioxide taken in / locked up (by trees)less photosynthesis?????????increase in methane in atmospheredue to rice production / cattleextra informationignore references to oxygenaccept explanations of the effect of water (vapour)[6]Q23.(a)????any one from:ignore ‘check temperature’?????????add a water bath?????????heat screen?????????use LED?????????low energy bulb / described1(b)????(i)??????rate / number of bubbles decreasesaccept converse with reference to increasing light or shorter distanceorless oxygen / gas releasedignore reference to rate of photosynthesis1(ii)?????temperature / CO2 (concentration)accept ‘it was too cool’ or not enough CO2accept number of chloroplasts / amount of chlorophyllallow heatallow CO2do not allow CO21(c) ????Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response. Examiners should also refer to the information in the Marking guidance, and apply a ‘best-fit’ approach to the marking.0 marksNo relevant content.Level 1 (1-2 marks)There is a brief description of at least 1 tissue or at least 1 function of an indicated part of the leaf.The account lacks clarity or detail.Level 2 (3-4 marks)There is a clear description which includes at least 1 named tissue and at least 1 correct function described for an indicated part of the leaf.Level 3 (5-6 marks)There is a detailed description of most of the structures and their functions.Examples of responses:?????????epidermis?????????cover the plant?????????mesophyll / palisade?????????photosynthesises?????????phloem ?????????xylem?????????transport.The following points are all acceptable but beyond the scope of the specification:?????????(waxy) cuticle – reduce water loss?????????epidermis – no chloroplasts so allows light to penetrate?????????stomata / guard cells – allow CO2 in (and O2 out) or controls water loss?????????palisade (mesophyll) – many chloroplasts to trap light– near top of leaf for receiving more light?????????spongy (mesophyll) – air spaces for rapid movement of gases6[9]Q24.(a)????use of quadrat / point frameallow description1randomly placed / random samplingignore reference to transects1(b)???? (i)??????61(ii)?????more light in A / in field / where sunnyignore sun1more / better / faster photosynthesis in A / with more lightallow converse1(iii)????use light meter / measure light intensity in both habitats1take many measurements at same time of the day1orlaboratory / field investigation with 2 batches high light and low light (1)count or number of flowers in each (1)counting point is dependent on investigation point(c) ????more glucose / energy availableallow other named product eg proteinallow if more energy produced1for growthdependent on 1st mark1[9]Q25.(a)???? (i)??????C and Dno mark if more than one box is ticked1(ii)?????any one from:do not allow if other cell parts are given in a list?????????(have) cell wall(s)?????????(have) vacuole(s)1(b)???? (i)??????Aapply list principle1(ii)?????Dapply list principle1(c) ????respirationapply list principle1[5]Q26.(a)????The starch is stored for use laterno mark if more than one box is ticked1(b)???? (i)??????any two from:do not accept temperatureapply list principleignore reference to time?????????carbon dioxide (concentration)?????????light intensity?????????light colour / wavelengthallow 1 mark for light if neither intensity or colour are awarded?????????pH?????????size / amount of pondweed / plant?????????same / species / type pondweed?????????amount of water in the tubeignore amount of water alone2(ii)?????number / amount of bubbles or amount of gas / oxygenallow volume of bubbles (together)ignore ‘the bubbles’ unqualified1(relevant reference to) time / named time intervalallow how long it bubbles fordo not accept time bubbles start / stopignore speed / rate of bubblingignore instrumentsdo not accept other factors eg temperatureaccept how many bubbles per minute for 2 marks1(c)???? (i)??????temperatureallow heat / cold / °C1(ii)?????carbon dioxide / CO2allow CO2do not accept CO21[7]Q27.(a)???? oxygenallow O2 / O2do not accept O2 or O1(b)???? (i)??????light1(ii)?????chlorophyll1(iii)????decrease1(c) ????any three from:?????????for respiration / energydo not accept use energy for photosynthesis?????????to make cellulose / starchaccept named carbohydrate other than glucose?????????to make lipid / fat / oilaccept fatty acid / glycerol?????????to make proteinaccept named protein / amino acid / named amino acid?????????to build big molecules from small molecules / metabolismif no other marks awarded for making molecules allow 1 mark for growth / repair / new cells3[7]Q28.(a)???? (i)??????decrease1rate of decrease slows1(ii)?????any one from:?????????more use of disinfectantallow any reasonable increase in hygiene or sterilisation precautions?????????more use of hand washing?????????more careful / more often cleaning of patient facilities?????????raised awareness / education about hygiene1Explanation:stops / reduces the bacteria being transferred / spreading1(iii)????800 – 500 / 800 × 100 =137.5 (%)correct answer with or without working gains 2 marks1(iv)????any one from:?????????numbers quite low now so hard to reduce further?????????was a big campaign / much publicity (in 2009) so more people already doing it?????????hygiene / cleaning now good so hard to improve?????????hospitals short of money so less staff to clean1(b) ????mutation occurred giving resistance (to methicillin)do not accept overuse caused mutation1resistant bacteria not able to be treated / not killed1these bacteria multiplied / reproduced / spread quickly1[10]Q29.(a)????xylem and phloemeither orderallow words ringed in boxallow mis-spelling if unambiguous1(b)????(i)??????movement / spreading out of particles / molecules / ions / atomsignore names of substances / ‘gases’1from high to low concentrationaccept down concentration gradientignore ‘along’ / ‘across’ gradientignore ‘with’ gradient1(ii)?????oxygen / water (vapour)allow O2 / O2ignore O2/ Oallow H2O / H2Oignore H2O1[4]Q30.(a)????LHS – carbon dioxide / CO2allow CO2ignore CO21RHSin either orderglucose / carbohydrate / sugarallow starchallow C6H12O6 / C6H12O6ignore C6H12O61oxygenallow O2 / O2ignore O2 / O1(b) ????any five from:?????????factor 1: CO2 (concentration)?????????effect - as CO2 increases so does rate and then it levels off or shown in a graph?????????explanation:(graph increases) because CO2 is the raw material or used in photosynthesis / converted to organic substance / named egor(graph levels off) when another factor limits the rate.accept points made via an annotated / labelled graph?????????factor 2: temperatureallow warmth / heat?????????effect – as temperature increases, so does the rate and then it decreases or shown in a graphallow ‘it peaks’ for description of both phases?????????explanation:(rise in temp) increases rate of chemical reactions / more kinetic energyallow molecules move faster / more collisionsor(decreases) because the enzyme is denatured.context must be clear = high temperature?allow other factor plus effect plus explanation:eg light wavelength / colour / pigments / chlorophyll / pH / minerals / ions / nutrients / size of leaves2nd or 3rd mark can be gained from correct description and explanation5[8]Q31.(a)????water1oxygenin this order onlyaccept correct chemical symbolsallow H2O / OH21(b) ????allow light (in / through) / need lightdo not accept attracts lightignore heat / moisture / carbon dioxideignore so the plants can be seenaccept the converse, ie the black plastic bag would not let light in (1)1for photosynthesis / make sugar / glucoseso there would be no photosynthesis (1)do not allow make food unqualified1(c) ????Increase (in leaves / new leaves) ignore growth unqualified1(then) level off or number of (new) leaves (then) stays the same 1numerical statement eg max at 3 tablets / 5 (new) leavesshould refer to one of the first two marking pointsfor every extra tablet get 1 extra leaf = 2 marksfor every extra tablet get 1 extra leaf then it levels off = 3 marks1[7]Q32.(a)????? (i)?????sunignore lightapply list principle1(ii)?????photosynthesisapply list principleallow approximate spellingdo not accept phototropism1(b)???? (i)?????chemical1(ii)?????carbon dioxide1(iii)????carbohydrates1(c) ????As carbon dioxide from the caterpillarif more than 2 boxes ticked deduct one mark for each additional incorrect box1As faeces (droppings) from the blue-tit1[7]Q33.(a)???? (LHS) water / H2Oallow H2Odo not accept H2O1(RHS) glucose / sugar / C6H12O6allow starch / carbohydrateallow C6H12O6do not accept C6H12O61(b)???? (i)????? 1 arbitrary unitextra box ticked – cancel1(ii)???? 2101(iii)????carbon dioxide / CO2 / CO2ortemperature / heat / warmthdo not accept CO2ignore mineral ions ignore water1[5]Q34.(a)???? LHS: carbon dioxide AND waterin either orderaccept CO2 and H2Oallow CO2 and H2Oif names given ignore symbolsdo not accept CO2 / H2O / Co / COignore balancing1RHS: sugar(s) / glucose / starch / carbohydrate(s)accept C6H12O6allow C6H12O6do not accept C6H12O61(b)???? (i)????? light is needed for photosynthesisorno photosynthesis occurred (so no oxygen produced)1(ii)???? oxygen is needed / used for (aerobic) respirationfull statementrespiration occurs or oxygen is needed for anaerobic respiration gains 1 mark2(c)???? (i)????? (with increasing temperature) rise then fall in rate1use of figures, iemax. production at 40 °Cor maximum rate of 37.5 to 381(ii)???? 25 – 35 °Ceither faster movement of particles / molecules / more collisions or particles have more energy / enzymes have more energy1or temperature is a limiting factor over this range40 – 50 °Cdenaturation of proteins / enzymesignore denaturation of cellsignore stomata1(d)???? above 35 °C (to 40 °C) – little increase in rateor > 40 °C – causes decrease in rate1so waste of money or less profit / expensive1because respiration rate is higher at > 35 °Correspiration reduces the effect of photosynthesis1[12]Q35.(a)???? 7.15 to 7.45 am and 7.15 to 7.45 pmboth required, either orderaccept in 24 hr clock mode1(b)?????(i)????? 111(ii)?????32.5 to 33allow answer to (b)(i) + 21.5 to 221(c) ????any two from:?????????more photosynthesis than respiration?????????more biomass / carbohydrate made than usedallow more food made than used?????????so plant able to grow / floweraccept plant able to store food2[5]Q36.(a)????? (i)?????70award 2 marks for correct answer irrespective of workingallow 1 mark for 30 + 10 + 24 + 6 (with wrong answer or no answer), do not award this sum if other figure(s) are included in the addition2(ii)?????6award 2 marks for correct answer irrespective of workingaward 2 marks for correct answer to (a)(i) – 64 (ecf)award 1 mark either for 70 – 64 or answer to (a)(i) – 64 with no answer or incorrect answer2(b)???????? photosynthesis.1[5]Q37.(a)????? (i)?????colour of light / bulb / lampallow wavelength for colourallow bulb alonedo not accept light / colour unqualified1(ii)?????any one from eg?????????temperatureallow heat?????????light intensity or distance between lamp and plant / tubeallow amount / brightness of lightignore light unqualified?????????carbon dioxideallow symbols?????????other light in roomallow use a dark room?????????mass / size / amount / age / type of pondweedallow same piece of pondweedignore pondweed unqualified?????????volume / amount of waterignore reference to time1(iii)????improved reliabilityallow for reliability or less likely to lose countorcan spot anomalies / changesallow reference to calculating a mean / averageignore reference to accuracy / precision / fair1(b)?????(i)????? green1(ii)?????any two from:ignore references to colour?????????least / less bubbles / gas / oxygen / meanreference to least / less needed only once, in context, for 2 marks?????????least / less photosynthesis?????????least / less glucose / sugar / carbohydrate / food madeonly penalise no once, ieno bubbles = 0 markno bubbles so no photosynthesis = 1 markallow most / more green light reflected (by chloroplasts)2[6]Q38.(a)???? add mineral ions to the soilextra box ticked cancels the mark1(b) ????increasing the temperatureeach extra box ticked cancels 1 mark1turning lights on at night1[3]Q39.any three from:maximum 2 marks if only advantages or only disadvantages givenignore references to cost unqualifiedadvantages: (max 2)ignore reference to fresher?????????less transport / example of transport or less fuel usedaccept implication eg less food milesallow no transport / fuel costs?????????less pollution / exampleaccept eg less carbon dioxide / smaller carbon footprintallow no pollution / example?????????support of local / UK economy / farmersdisadvantages: (max 2)?????????not available all year?????????may require use of heat / light?????????(production of) heat / light causes pollution[3]Q40.(a)????? (i)?????increase (and then level off) and max / up to at 0.15 (%) (carbon dioxide)ignore references to oxygen concentration onlyignore mention of 231(ii)?????CO2 is limiting at low CO2 / at firstignore specific numbers1light is limiting at high CO2 / at end1(b) ??????????????????????mark both parts togethereffect: (oxygen) falls1explanation: (oxygen) used for respirationif no other marks awarded allow (effect) no change and (explanation) no photosynthesis for 1 mark1(c) ????more chlorophyll / chloroplasts1allows more photosynthesis / descriptionfor both marks must refer to more at least once1[7]Q41.(a)??????(i)???? oxygen produced1(ii)???? any one from:???????? average / mean / medianignore reliable / precise / accurate???????? some may be anomalousallow some may not float1(b)??????(i)????????????? do not allow answers in terms of time onlyif candidate answers in terms of comparing rate of change then the rate of change of photosynthesis must be in the correct direction for 1 markany two from:???????? low intensity / below 12.5 / 2.5 - 12.5 (units of light) flat wrack /it, rate of photosynthesis faster or saw wrack rate of photosynthesis slowerallow any value in range???????? high intensity / above 12.5 / 12.5 - 15 (units of light) flat wrack / it,rate of photosynthesis slower or saw wrack rate of photosynthesis fasterallow any value in range???????? same (rate) at 12.5 units2(ii)???? any two from:???????? saw wrack receives less lightaccept converse if clear reference to bladder wrack???????? less photosynthesisif first and second responses, ‘less’ needed only once???????? orless carbohydrate / sugar / starch production???????? when tide is in or at high tide or any tide above low tideaccept saw wrack covered by water / submerged longer / morereference to position on shore is insufficient2[6]Q42.(a)???? the starch is stored for later use.1(b)?????(i)????? any two from:do not accept temperature-apply list principleignore reference to time???????? carbon dioxide (concentration)???????? light intensityallow one mark for light if neither intensity or colour are awarded???????? light colour / wavelength???????? pH???????? size / amount plant???????? same / species / type plantallow ‘the plant’????? amount of water in the tubeignore amount of water alone2(ii)???? number / amount of bubbles or amount of gas / oxygenallow volume of bubbles (together)ignore ‘the bubbles’ unqualified1(relevant reference to) time / named time intervalallow how long it bubbles fordo not accept time bubbles start / stopignore speed / rate bubblesignore instrumentsdo not accept other factors eg temperatureaccept how many bubbles per minute for 2 marks1(c)?????(i)????? temperatureallow heat / °C / cold1(ii)???? carbon dioxide / CO2CO2 / CO2 / Co2 / Co2 / co2 / co2do not accept CO / 2CO1[7]Q43.(a)???? any one from:???????? (type of / amount of) soil / minerals / nutrients / pH???????? amount of water / time of watering???????? space between plants / plants and wall???????? time for growthlist principleignore carbon dioxide / same number of plants / fooddo not allow temperature / light / exposure to wind1(b)???? (i)????? North wall1(ii)???? nuggetlist principle1(c)???? has not tested all varieties / nugget / champion against all wallsdo not allow repeat experiment1[4]Q44.(a)???? (i)????? water / H2Oallow hydrogen oxide1???????? oxygen / O2 / Oallow upper and lower case symbols and superscriptsanswers must be in this order1(ii)???? respiration in the plantallow clear indication of correct response1(b)???? light (no light) / light intensityignore references to the card / covered / uncovered1????????? chlorophyll (no chlorophyll) / chloroplastallow leaf colour or both green and white given1(c)???? (i)????? no light (received) or it’s darkallow no photosynthesisdo not allow little light / photosynthesisignore sunapply list principle for other factors1(ii)???? no chlorophyll / chloroplasts (present)allow no / little photosynthesisallow white or not green or little chlorophyll / few chloroplastsapply list principle for other factors1[7]Q45.(a)???? (i)????? ??both correct = 2 marksone correct = 1 markextra line from a statement cancels the mark2(ii)???? 1st space: carbon dioxideallow CO2 (ignore superscript)do not allow CO alone1???????? 2nd space: glucose / sugar / starch / carbohydrate1(b)???? (i)????? any one from:???????? move lamp or change distance between lamp and plantignore measure the distance???????? change wattage / power of (light) bulbdo not accept just “change bulb”???????? change voltage / power supply to the (light) bulb???????? change the number of lamps???????? put translucent material between lamp and plantaccept examples, eg tracing paper / filtersdo not accept coloured filters1(ii)???? rises1???????? levels offignore numbers1(iii)???? idea that it levels off???????? or???????? does not increase at all light intensities???????? or???????? it only increases to a certain amountanswers should relate to photosynthesis and not to bubbling1[8]?Q46.(a)???? photosynthesis1(b)???? oxygen1(c)???? chlorophyll1(d)???? starch1[4]Q47.(a)???? any three from:???????? ((mean) mass) increases up to 7 / 8 units (of light) then levels off???????? light limiting factor up to 7 / 8 units???????? for photosynthesismust be in correct context???????? other factor / temperature limiting above 7 / 8 units3(b)???? any two from:???????? cost of providing conditions / heat / light / CO2???????? effect of treatment on profitallow too much of factor is wasteful???????? relevant use of data from graph eg limiting factors???????? named other factors eg fertiliser / pest control / weeds /density of plantingallow taste / appearance2(c)???? nitrate function????????? produce amino acids / proteins / enzymesignore DNAdo not allow chlorophyll1????????? nitrate deficiency????????? stunted growthallow descriptionignore plant dies1????????? magnesium function????????? produce chlorophyllignore chloroplasts1????????? magnesium deficiency????????? yellow leaves / plantignore plant dies1[9]Q48.(a)???? (i)????? L.H.S. – water / H2O1R.H.S. – oxygen / O2accept H2Oaccept O2 / O1(ii)???? chlorophyllmust make it clear that it is the chlorophylldo not credit chloroplast on its owndo not accept chloroplast / chlorophyllwithout indication that it is chlorophyll1(b)???? (i)????? light intensity / temperature is high enough for higher rate or light /temperature is not limiting1???????? low CO2 available or not enough CO2available or rate would be higher with more CO21(ii)???? temperatureallow water / rainallow (too) cold / hot as a minimumallow wave length / frequency / colourignore ionsignore heat1[6]Q49.(a)???? burning fossil fuels / coal / gas / oilaccept driving vehicles / eg carsaccept coal-fired power stationaccept car emissionsignore combustion unqualifieddo not accept power station unqualifieddo not accept using fossil fuels1(b)???? (i)????? (SO2) makes it acidic / makes acid rain / lowers pH1(ii)???? any one from:(SO2) kills leaves reduces number of leaves reduces leaf areaor smaller leaves causes fewer leaves to growignore correct extras, eg withered, yellow etc?? 1(c)???? any two from:????????? (fewer leaves / less leaf S.A) so less photosynthesis????????? less food / less sugar / less starch supplied (to roots / to stems)????????? (SO2) lowers pH of soil / makes soil acidic????????? ions (/minerals / salts / nutrients) less available (to plants)accept don’t get enough nutrients2[5]Q50.(a)???? carbon dioxide/CO21(b)???? through the roots/root hairsdo not accept leaves1(c)???? oxygen1????????? sugar/glucose/other named sugar/starch/carbohydrate1(d)???? award one mark for each mark pointn.b. accept chloroplast for chlorophylln.b. credit the candidate who answers in terms of the white areas of the leafchlorophyll is greene.g. green areas have chlorophyll1????????? chlorophyll/green is needed for photosynthesise.g. it is only in green areas thatphotosynthesis can take placeafter this point do not penalise a candidate if they do not refer to photosynthesis1light is needede.g. it does not happen in the darkdo not accept sunshine/sun1photosynthesis produces/makes starche.g. starch is madesoe.g. ‘you need light to make starch’ scores 3rd and 4th marking points‘you need chlorophyll and light for photosynthesis’ scores on the 2nd and 3rd marking points‘photosynthesis makes starch and you need green leaves and light for it to work’ scoreson the 2nd, 3rd and 4th marking points1[8]Q51.(a)???? water [1]oxygen [1](sun) light or solar [1]do not accept sun’schlorophyll [1]do not accept chloroplasts4(b)???? any two from:????????? stored as fructosestored as sucrosestored as starchstored as oil or lipidmoved or transported away in the phloemdo not accept “stored” by itself????????? respired or burnt up for energy orfuel changed to proteinchanged to cellulosechanged to fructosechanged to starchchanged to oil or lipiddo not accept “food for plant”do not accept “used up” by itself2(c)???? (i)????? roots or root hair (cells)1(ii)???? the mineral salts are (dissolved) in water [1]???????? water transports salts throughout the plant or water enables osmosis or diffusion to take place [1]2(d)???? (i)????? plants grow better with some nutrients than noneorplants grow better with nitrates than withoutcomparison is neededaccept “faster” as equivalent to “better”accept don’t grow well with only water1(ii)???? 0.14(g)units not needed1(iii)???? making protein or amino acidsdo not accept help them growaccept named protein or DNA or chlorophyll1any two from:(iv)??? type or variety or starting weight or2(iii)???? size of seedlingskeep the environment the sameonly if light or temperature or daylength not already credited???????? lighttemperature not heattime of growthdo not accept the same equipmentdo not accept help them grow1???????? day lengthamount of culture solution or/size ofaccept named protein, DNA chlorophyll???????? boiling tubenumber of seedlings per tubepHCO2humidity[15]Q52.(a)???? carbonwateroxygenlightchlorophyllstarch1 mark each6(b)???? leaf (or named part of leaf)orchloroplastsaccept anywhere greendo not credit chlorophyll unless qualified1(c)???? water through the rootsorroot hairsorby osmosisdo not credit where the candidate is unclear about which is which1????????? CO2 through the leaforstomataorby diffusion1(d)???? any one point:????????? increased CO2 concentrationincreased water supplyincreased temperature (up to a point)increased light (intensity)accept altered light quality by less green or increasing other coloursaccept increased duration of exposure to lightdo not credit sun or sunshineaccept CO2 from respiration1?[10]Q53.(a)???? (i)????? light or solardo not credit sun’s energydo not credit radiant1(ii)???? chlorophyll1(iii)???? chloroplast1(iv)??? CO2 + H2Oreactants identified (accept words)1???????? C6H12O6 + O2products identified (accept words)1???????? 6CO2 + 6H2O → C6H12O6 + 6O2balanced equation1(b)???? any two from:????????? increased CO2 concentration????????? increased water supply????????? increased temperature (up to a point)increased light intensitydo not accept heat or warmth????????? altered light quality by less green orincreasing other colours2(c)???? any four points???????? palisade (mesophyll)???????? lots of chloroplasts or chlorophyllor main site for photosynthesisor absorb maximum amount of light???????? guard cells???????? CO2 in or O2 out or water vapourout???????? controls size of stoma or pores inleafallow stomata4[12] ................
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