Data collection techniques and data analysis — Paper 2 — A Level Environmental Management (AS only) 8291 topical questions

Question 1

Fig. 1.1 shows the international border between the Caribbean countries Haiti and Dominican Republic. international border Haiti Dominican …

Accepted Answer

1(a)(i) Haiti trees are missing / no trees / only small trees; (mountain) soil exposed / bare earth / appears to lack plants; small scrub bushes / grassland; lacks shelter; max 2 1(a)(ii) humans remove trees; for fuel; for agriculture / grazing land; lack of control / law enforcement; poverty; max 2 2 1(a)(iii) soil dries out; exposed to forces of erosion; example e.g. wind; no roots to bind the soil / hold it in place; reduction in litter layer; loss of fertility; max 3 3 1(a)(iv) loss of shelter; loss of food; disruption of food web; reduction in water availability; reduction in species variety / gene pool; max 2 2 1(b)(i) 3-4 points correctly plotted; 5 points correctly plotted; line of best fit accurately drawn; 3 Question Answer Marks 1(b)(ii) there has been a steep decline in the amount remaining; the line off best fit is a straight line; the rate of loss is consistent; use of figures; max 1 1 1(c)(i) five; 1 1(c)(ii) plants / producers / first / 1; 1 1(c)(iii) (they feed in) two; trophic levels; they eat plants; and insects; max 2 2 1(d) increasing light intensity; increases rate of photosynthesis; more glucose produced; increasing growth; until another factor becomes limiting; named factor; max 3 3

Question 2

Fig. 1.1 shows the international border between the Caribbean countries Haiti and Dominican Republic. international border Haiti Dominican …

Accepted Answer

1(a)(i) Haiti trees are missing / no trees / only small trees; (mountain) soil exposed / bare earth / appears to lack plants; small scrub bushes / grassland; lacks shelter; max 2 1(a)(ii) humans remove trees; for fuel; for agriculture / grazing land; lack of control / law enforcement; poverty; max 2 2 1(a)(iii) soil dries out; exposed to forces of erosion; example e.g. wind; no roots to bind the soil / hold it in place; reduction in litter layer; loss of fertility; max 3 3 1(a)(iv) loss of shelter; loss of food; disruption of food web; reduction in water availability; reduction in species variety / gene pool; max 2 2 1(b)(i) 3-4 points correctly plotted; 5 points correctly plotted; line of best fit accurately drawn; 3 Question Answer Marks 1(b)(ii) there has been a steep decline in the amount remaining; the line off best fit is a straight line; the rate of loss is consistent; use of figures; max 1 1 1(c)(i) five; 1 1(c)(ii) plants / producers / first / 1; 1 1(c)(iii) (they feed in) two; trophic levels; they eat plants; and insects; max 2 2 1(d) increasing light intensity; increases rate of photosynthesis; more glucose produced; increasing growth; until another factor becomes limiting; named factor; max 3 3

Question 3

(a) Fig. 2.1 shows an annual climate graph for Madagascar and the changes in the area of the Madagascar rainforest. 30 350 28 300 26 250 24…

Accepted Answer

2(a)(i) between 7 and 9 degrees; 1 2(a)(ii) between 310 and 320 mm; 1 2(a)(iii) large areas of rainforest lost; from the East; areas showing gaps between rainforests; largest remaining in north / north-east; coastal areas have disappeared first; 4 Question Answer Marks 2(a)(iv) forest clearing; for subsistence farming; logging; for timber; urban development; roads; airport; global warming; due to loss of vegetation / desertification; forest fires; 4 2(a)(v) temperature; increases rates of activity; e.g. photosynthesis; water; maintains high humidity; nutrient rich soil; high biodiversity; high level of plant growth / primary productivity; rapidly recycled minerals and organic matter; 2 2(b) loss of nutrients; named example; plants grow less well; loss of structure; roots have less structure to hold; litter layer reduced even further; less water available; disruption of local hydrological cycle; 4 Question Answer Marks 2(c) education; encourage people to respect the environment; legislation; fines for deforestation; licensing to control logging / mining; farmers given support to fertilise existing land; protected area; encourage ecotourism; locals earn a living from the biodiversity; 4

Question 4

In 2020, Ethiopia, a country in Africa, had 15% of its land covered by forest. Fifty years ago, 40% of Ethiopia was covered by forest. (a) …

Accepted Answer

4(a)(i) any one from: satellite; geospatial systems / geographical information systems / GIS; crowd sourcing / surveying; arial photographs / drones; 1 4(a)(ii) any two or developed from: habitat lost / habitat fragmentation; reduces food / disrupts food chains or web / increase competition / reduces carrying capacity; increased predation / less protection from predators; disrupts ecological corridors; changes land use / primary forest replaced by secondary forest; causes migration (of species); soil erosion; loss of, soil fertility / soil structure; 2 4(b)(i) forest cover is decreasing; 1 4(b)(ii) sectors in rank order largest first beginning at noon and proceeding clockwise; correct plotting  1%; sectors match key; 3 4(b)(iii) any one from: sample size; we need information on the method of collection; demographic / information about who has been sampled; 1 Question Answer Marks 4(c)(i) any one from: lack of water; disease; soil infertile / lack of nutrients; natural disaster / wildfires; eaten by livestock or animals; competition or described; tree stolen / damaged by people; removed as part of forest management / trees cut down / trees harvested; 1 4(c)(ii) any one from: cost; other priorities / not seen as important; public or political opinion / lack of volunteers to plant them; lack of land / area already forested; 1 4(c)(iii) any two from: improved soil e.g. improved structure / roots bind soil / improved nutrients / improved fertility; reduces global warming / reduces global temperatures; decreases evaporation from soil; increases interception; increases infiltration decreases run-off. increases (evapo)transpiration / increased water evaporating from leaves; leads to, moisture condenses / increases cloud cover / more precipitation; any one from: soil can absorb more water / soil can hold more water / water can soak into soil; increases or recharge groundwater stores / recharges aquifers; 3 Question Answer Marks 4(c)(iv) any three from: could become invasive; out compete native trees / deplete nutrients / increased competition in food chain / competition described / disrupt food chain / loss of biodiversity; no natural predators / not (local) food source toxic / poisonous; diseases; 3 4(c)(v) any four or developed from: (growing trees are) carbon capture or sinks; (mature trees are) carbon stores; during photosynthesis; reduce carbon dioxide / CO2 (from atmosphere); carbon dioxide + water  glucose + oxygen OR 6CO2 + 6H2O  C6H12O6 + 6O2 ; 4

Question 5

A report stated that 3 billion people cook their food using stoves that require open fires. Wood is a common fuel for the open fire used in…

Accepted Answer

5(a) for solar stove: max [5] advantages of solar stove: renewable energy; solar energy or sun is free to use; uses existing / local / same, materials for stove; saves time collecting fuel; does not produce smoke / smog / particulates / carbon dioxide emissions / produce carbon monoxide / less air pollution; does not cause respiratory disease / breathing difficulties / lung cancer / eye irritation / stated condition related to CO / named condition; not cutting down trees / less deforestation ; less risk of (uncontrolled) fires max [5] disadvantages of solar stove: expense of shiny surface; less reliable / can only be used, when or where sunny / at certain times of day / mealtimes must fit in with weather / less flexible use; used outside; not sturdy construction; food takes longer to cook; does not provide ash for use on soils; harder to build shiny surface / don’t have skills to self-build a shiny surface; 6 5(b)(i) any one from: regions can be (directly) compared; different regions have different numbers of people; 1 5(b)(ii) any three from low income people: greater number of homes with indoor wood / dung / open fire / unventilated stoves; have less access to electricity / less supply of (natural) gas / no alternatives to current fuel; homes not ventilated / limited technology or advancements; have more people per home / homes overcrowded; less access to medical facilities / poorer overall health; limited education; 3 Question Answer Marks 5(c)(i) any one from: origin of pollution not known / difficult to prove who caused the pollution / pollution comes from different countries; too many people cause the pollution / everyone contributes to pollution; lack of funds / lack of money / negative impact on economy; difficult to define pollution; some countries / people, have different priorities; pressure from (large) companies / lobbying; 1 5(c)(ii) any two from: economic reason; leads to loss of jobs; lack of alternatives e.g. no widespread electric vehicle use / lack of control over personal carbon footprint 2

Question 6

(a) A conservationist uses aerial photographs to estimate the population of a species of bird. Fig. 3.1 shows a drawing of the position of …

Accepted Answer

3(a)(i) A4: 4; D3: 5; 2 3(a)(ii) max [4] benefits max 3: can be counted remotely; data can be checked / hard copy of data; avoids bias; large areas can be covered; automated; doesn’t harm the birds / birds not disturbed; limitations max 3: relies on photographing all the birds / birds move; need aeroplane or satellite or drone to take the images / costly; difficult to count if birds on a grid line; reliant on suitable weather conditions; reliant on lack of dense groundcover; potential distortion (due to oblique angle); difficult to identify species of bird; 4 3(b)(i) 0.44; (1 – M1 =) 0.56; 2 3(b)(ii) Z is more diverse (than Y); 1 3(c)(i) any three from: tag / named example e.g. leg rings / tags / chip; recapture idea of capture: marked AND unmarked / random capture; named method of estimating population: Lincoln index; 3 Question Answer Marks 3(c)(ii) any two from: no death / no change in survival rate; no births; no migration; sampling methods are identical to first capture; random mixing of population; 2 3(d)(i) 5; 1 3(d)(ii) algae  zooplankton  (sandhill) crane; OR plants/seeds  (sandhill) crane  eagle 1 3(e) any three from: restrict number of birds hunted / number of birds killed; restricted times/season for hunting; enables birds to reproduce; birds given time to fatten (ready for migration); (sign) education / awareness; 3 3(f) loss of habitat / wetlands dry up; alter migration; loss of other species / loss of food source / disrupt food chain; introduces, invasive species/predators; 4

Question 7

(a) A conservationist uses aerial photographs to estimate the population of a species of bird. Fig. 3.1 shows a drawing of the position of …

Accepted Answer

3(a)(i) A4: 4; D3: 5; 2 3(a)(ii) max [4] benefits max 3: can be counted remotely; data can be checked / hard copy of data; avoids bias; large areas can be covered; automated; doesn’t harm the birds / birds not disturbed; limitations max 3: relies on photographing all the birds / birds move; need aeroplane or satellite or drone to take the images / costly; difficult to count if birds on a grid line; reliant on suitable weather conditions; reliant on lack of dense groundcover; potential distortion (due to oblique angle); difficult to identify species of bird; 4 3(b)(i) 0.44; (1 – M1 =) 0.56; 2 3(b)(ii) Z is more diverse (than Y); 1 3(c)(i) any three from: tag / named example e.g. leg rings / tags / chip; recapture idea of capture: marked AND unmarked / random capture; named method of estimating population: Lincoln index; 3 Question Answer Marks 3(c)(ii) any two from: no death / no change in survival rate; no births; no migration; sampling methods are identical to first capture; random mixing of population; 2 3(d)(i) 5; 1 3(d)(ii) algae  zooplankton  (sandhill) crane; OR plants/seeds  (sandhill) crane  eagle 1 3(e) any three from: restrict number of birds hunted / number of birds killed; restricted times/season for hunting; enables birds to reproduce; birds given time to fatten (ready for migration); (sign) education / awareness; 3 3(f) loss of habitat / wetlands dry up; alter migration; loss of other species / loss of food source / disrupt food chain; introduces, invasive species/predators; 4

Question 8

Fig. 3.1 shows a photograph of Stockton mine, a large coal mine in New Zealand. Fig. 3.1 (a) Coal is a fossil fuel. It is a non-renewable e…

Accepted Answer

3(a)(i) any one from: 1 oil; natural gas; uranium / nuclear; 3(a)(ii) any two from: 2 idea of inequality in global energy resources / more reserves in some countries than others; requires import of energy resource or electricity; limited alternatives of fossil fuels / reduction in a natural energy resource / some countries rely heavily on fossil fuels / main energy source; cost of energy will go up; 3(a)(iii) advantage: 2 existing resources last longer; disadvantage: does not solve the problem of finding an alternative; difficult to police / manage rationing strategy; 3(b)(i) any five from: 5 reference to where sampling will take place / mapping sampling points / random or systematic sampling stated or described; (small) hole for snail to fall into; count all (Mount Augustus) snail in trap; mark shells; with, e.g. correction fluid, nail varnish, marker pen; release back to same location; repeat (after at least 24 hours); repeat for different locations; 3(b)(ii) any two from: 2 all members of the population mix randomly; marks are not lost between samples; the mark does not harm the animal, e.g. making it more obvious to predators; the marks do not affect the chances of recapture; the animals are active; 3(c)(i) 4077; 1 3(c)(ii) any one from: 1 initially population increased; general decrease in population; since 2012; 3(c)(iii) (30% mortality) 15 (dead); 2 (50 – 15 =) 35; 3(c)(iv) any two from: 2 to protect from predators; to have a genetic record / for research or study; to ensure species does not become extinct; breeding programme; 3(d)(i) earthworm; 1 3(d)(ii) any one from: 1 rats become resistant to the poison; may affect non-target species / may poison other animals that eat the rat; builds-up in food chain / biomagnification; 3(e)(i) negative value / – symbol; 2 2; 3(e)(ii) 6.6 / 7; 1 3(e)(iii) any one from: 1 anomalous result; snail has disease / illness; 3(e)(iv) diet B is better because the snails increase more in mass (than A); 1

Question 9

A biologist wants to investigate the biodiversity in a stream using a kick sampling method. Fig. 3.1 is a field sketch of the stream. strea…

Accepted Answer

3(a) identify location to sample; 5 use of a net; opening of net facing upstream / against the direction of flow; kick stream bed in front of net (opening); for set period of time; count organisms collected in net; repeat (for same location / different time) and average; repeat for different location; 3(b)(i) 0.54; 1 3(b)(ii) 0.0144 / 0.01; 2 0.014 (answer given to two sig. figs); 3(b)(iii) yes or no with any two reasons: 2 data only shows diversity / value of 1 represents complete diversity / value of 0 represents complete uniformity; data shows stream is more diverse in 2020 than 2019; organism in stream in 2020 might be better suited to lower pH or acidic water; 3(b)(iv) any two from: 2 acid deposition; emissions from combustion of fossil fuels or car (exhausts) / SO2 or NOx in atmosphere; run-off from fields; due to fertiliser; industrial pollution / chemicals from factories; sewage waste;

Question 10

Approximately 623 million people practise open defecation. This is going to the toilet outside in fields, water bodies and open spaces. (a)…

Accepted Answer

4(a) any three from: 3 less open spaces (for privacy to open defecate); more people living in an area / increased population density; leads to increased risk of disease; from contaminated water / from contact with faeces; 4(b)(i) decomposer / decomposition; 1 4(b)(ii) any two from: 2 high ground water level / high water table (result in flooding); area prone to floods; area prone to drought / dry conditions; no access to water / not enough water to flush; 4(b)(iii) any one from: 1 kills the tiger worms; leaches into soil; products would kill bacteria and fungi which aid the decomposition; 4(c)(i) random; 2 (random) number generator / draw names out of a ‘hat’; OR systematic; assign everyone a number; e.g. every third house / every nth person; 4(c)(ii) any one benefit: 2 (type 1) easier to process / less data to process / less time consuming; any one limitation: limited by question asked / no idea of their opinion; 4(c)(iii) suitable yes / no question: 1 Is the TWT easy to use? Would you recommend the TWT to other people? 4(d) any one advantage: 2 cheaper / worms not needed; no need for water after use; familiar technology; easier or simpler to build; any one disadvantage: needs to be moved once full / faeces is not digested or broken down; increased risk of disease as faeces is left in the ground; difficult to dig a hole if ground rocky; pit must be deeper than TWT;

Question 11

Fig. 3.1 shows a photograph of Stockton mine, a large coal mine in New Zealand. Fig. 3.1 (a) Coal is a fossil fuel. It is a non-renewable e…

Accepted Answer

3(a)(i) any one from: 1 oil; natural gas; uranium / nuclear; 3(a)(ii) any two from: 2 idea of inequality in global energy resources / more reserves in some countries than others; requires import of energy resource or electricity; limited alternatives of fossil fuels / reduction in a natural energy resource / some countries rely heavily on fossil fuels / main energy source; cost of energy will go up; 3(a)(iii) advantage: 2 existing resources last longer; disadvantage: does not solve the problem of finding an alternative; difficult to police / manage rationing strategy; 3(b)(i) any five from: 5 reference to where sampling will take place / mapping sampling points / random or systematic sampling stated or described; (small) hole for snail to fall into; count all (Mount Augustus) snail in trap; mark shells; with, e.g. correction fluid, nail varnish, marker pen; release back to same location; repeat (after at least 24 hours); repeat for different locations; 3(b)(ii) any two from: 2 all members of the population mix randomly; marks are not lost between samples; the mark does not harm the animal, e.g. making it more obvious to predators; the marks do not affect the chances of recapture; the animals are active; 3(c)(i) 4077; 1 3(c)(ii) any one from: 1 initially population increased; general decrease in population; since 2012; 3(c)(iii) (30% mortality) 15 (dead); 2 (50 – 15 =) 35; 3(c)(iv) any two from: 2 to protect from predators; to have a genetic record / for research or study; to ensure species does not become extinct; breeding programme; 3(d)(i) earthworm; 1 3(d)(ii) any one from: 1 rats become resistant to the poison; may affect non-target species / may poison other animals that eat the rat; builds-up in food chain / biomagnification; 3(e)(i) negative value / – symbol; 2 2; 3(e)(ii) 6.6 / 7; 1 3(e)(iii) any one from: 1 anomalous result; snail has disease / illness; 3(e)(iv) diet B is better because the snails increase more in mass (than A); 1

Question 12

The Sous reservoir in the Czech Republic is a source of drinking water for 100 000 people in the region. The area has been affected by acid…

Accepted Answer

2(a)(i) idea of (atmospheric) deposits with a pH < 5.6; 1 2(a)(ii) any three from: M1 combustion or burning of fossil fuels; M2 formation sulfur dioxide or SO2 / sulfur reacts with oxygen / S + O2  SO2; M3 (their M2) gas reacts with water or H2O; M4 to form sulfuric acid / H2SO4; 3 2(a)(iii) any three strategies/developments from: M1 reduce use of fossil fuels / use renewable resources / use stated renewable resource; SO2: M2 flue gas desulfurisation / flue gas removal from chimneys; M3 fuel desulfurisation; NOx: M4 catalytic convertors; 3 Question Answer Marks 2(b)(i) 1.6; 1 2(b)(ii) anomalous data point / outlier; 1 2(b)(iii) any two from: M1 pH values similar / sulfate concentrations vary, at each location; M2 low pH / acidic pH / pH less than drinking water; M3 high (concentration of) sulfate / more (concentrated with) sulfate than drinking water; M4 idea that (reservoir) water affected by acid deposition; 2 2(b)(iv) to remove any impurities from the bottle; 1 2(b)(v) any two from: M1 time; M2 water temperature; M3 air temperature; M4 weather conditions; M5 water depth of sample; M6 volume of water collected; 2 2(b)(vi) any two from: M1 more (than 3) locations; M2 not all in one place / spread out sampling; M3 longer sampling period / more than three years of sampling / more than once a month; M4 different depths; 2 2(c)(i) plankton; 1 2(c)(ii) second; 1 Question Answer Marks 2(c)(iii) any three from: M1 lost as heat; M2 idea of only 10% of energy passed between levels / 90% is lost; lost through: M3 respiration; M4 digestion; M5 (excreted) waste (products); M6 movement; M7 death / decomposition; M8 maintaining body temperature / thermoregulation; M9 feeding / consumers do not consume the whole organism; 3

Question 13

(a) Brazil’s Atlantic forest contains approximately 6000 plant species, 263 amphibian species and 160 species of mammal, which are found no…

Accepted Answer

3(a)(i) M1 two correct plots; M2 bars same width as existing bars; 2 3(a)(ii) 1999 AND 2000; 1 3(a)(iii) any three from: M1 population increase; M2 logging / timber; M3 (wild)fire; M4 drought / lack of water; M5 disease; M6 invasive species; M7 (bio) fuels; land needed for: M8 housing / buildings / urbanisation / industrialisation / construction / commercial / business; M9 roads / infrastructure; M10 agriculture / production of food / grazing / crops / farms; M11 mineral extraction / mining; M12 hydroelectric / reservoirs; 3 Question Answer Marks 3(b) any three from: M1 idea of: ($21 million of) Brazil’s debt (to USA) cancelled; money is then invested in ways to improve the forest: M2 idea of preserving or increasing biodiversity; M3 ecotourism; M4 national parks; M5 afforestation / re-forestation / replanting; M6 compensating farmers / helping people financially / financial incentive to individuals (to not cut down trees); 3 3(c)(i) any three from: M1 no information on number of houses in street; M2 may be too much data or too little data, to analyse; M3 only women selected / ora; M4 only 2030 year olds selected / no stated other age range; M5 only Sao Paulo selected / only one street or area selected; M6 data is not representative; M7 data could be biased; 3 3(c)(ii) quick or easy / do not have to read long responses / answers are limited or quantifiable / not ambiguous / does not need interpretation / AVP; 1

Question 14

Fig. 2.1 shows the African clawed frog and tadpole. The frog is native to Africa. 1–5 cm 5–12 cm tadpole mature frog Fig. 2.1 The female Af…

Accepted Answer

2(a)(i) 6; 1 2(a)(ii) sensible linear scale and data occupying over half the grid; axes labels AND unit; e.g. y-axis label:( mean) number of frogs AND x-axis: artificial light / hours per day 5 correct plotted points  half small square; bars of equal width that are not touching; 4 2(a)(iii) anomalous result / outlier; 1 Question Answer Marks 2(a)(iv) any one from: the more artificial light per day the fewer the number of adult frogs; tadpoles are less likely to mature into adult frogs with artificial light; 1 2(a)(v) any one from: do not know the original number of eggs; each female may lay different numbers of eggs; small sample of frogs / only five frogs sampled; 1 2(b) stated size of quadrat e.g. 1 m  1 m quadrat; stated sampling distances e.g. every 5 metres / systematic e.g. every metre OR distances selected at random; count number of frogs (in the quadrat); repeat AND take an average; 4 2(c)(i) not representative / all in one place; 1 2(c)(ii) 288; 1 2(d) any two from: can survive in conditions other frogs cannot; outcompetes other frogs; produces a lot of eggs; accidental introduction (by humans); no predators; 2 2(e) any one from: temperature; humidity; water; oxygen; light; pH; 1 2(f)(i) snake; 1 2(f)(ii) 4th; 1 Question Answer Marks 2(f)(iii) decrease population AND, more predators / more are eaten; 1

Question 15

Fig. 2.1 shows the African clawed frog and tadpole. The frog is native to Africa. 1–5 cm 5–12 cm tadpole mature frog Fig. 2.1 The female Af…

Accepted Answer

2(a)(i) 6; 1 2(a)(ii) sensible linear scale and data occupying over half the grid; axes labels AND unit; e.g. y-axis label:( mean) number of frogs AND x-axis: artificial light / hours per day 5 correct plotted points  half small square; bars of equal width that are not touching; 4 2(a)(iii) anomalous result / outlier; 1 Question Answer Marks 2(a)(iv) any one from: the more artificial light per day the fewer the number of adult frogs; tadpoles are less likely to mature into adult frogs with artificial light; 1 2(a)(v) any one from: do not know the original number of eggs; each female may lay different numbers of eggs; small sample of frogs / only five frogs sampled; 1 2(b) stated size of quadrat e.g. 1 m  1 m quadrat; stated sampling distances e.g. every 5 metres / systematic e.g. every metre OR distances selected at random; count number of frogs (in the quadrat); repeat AND take an average; 4 2(c)(i) not representative / all in one place; 1 2(c)(ii) 288; 1 2(d) any two from: can survive in conditions other frogs cannot; outcompetes other frogs; produces a lot of eggs; accidental introduction (by humans); no predators; 2 2(e) any one from: temperature; humidity; water; oxygen; light; pH; 1 2(f)(i) snake; 1 2(f)(ii) 4th; 1 Question Answer Marks 2(f)(iii) decrease population AND, more predators / more are eaten; 1

Question 16

(a) A student investigates the concentration of nitrate ions in a lake. The student makes the following hypothesis: ‘The concentration of n…

Accepted Answer

2(a)(i) (air) temperature; 1 2(a)(ii) any one from: 1 volume / amount of water; collect water, in same way / at same depth; time of day / time of collection; location e.g. side of lake / position of sampling; 2(a)(iii) any two from: 2 results can be compared; anomalous results exclude / identifies anomalous results or outliers / identify mistakes; average/mean found; averaging/identifying anomalies increases accuracy; averaging reduces effect of random errors / reduces margin of error; confirm results / proves or disproves results; 2(b)(i) answer to one decimal place: 3.2; 2 unrounded answer: 3.16; 2(b)(ii) 16; 1 2(b)(iii) no; 1 AND any one from: valid evidence e.g. highest temperature and lowest concentration or correctly quoted data; no correlation (between air temperature and concentration of nitrate ions); 2(b)(iv) systematic sampling described e.g. every nth distance across lake selected; 1 2(b)(v) any one from: 1 data only gives information on nitrate; only five samples / not representative; may contain other pollutants / named pollutant; 2(c)(i) any three from: 3 nitrate concentrations (in wells) greatest in centre of state / towards middle / increases close to the state capital; cluster in southwest corner > 10.0 (mg /L ); between 3.0–10.0 (mg / L) in south east corner / between Wisconsin and Iowa; low concentrations along border with Lake Superior / in North / border with Canada; low concentrations around the state capital; 2(c)(ii) leaching; 1 2(d) any two from: 2 piped / from taps; aquifer; borehole; gravity-fed; reservoirs / dams; 2(e)(i) any two from: 2 people spend hours collecting water; cannot work / cannot earn money; cannot attend school / get an education; people drink contaminated water; people become ill (dehydrated / water-borne disease) so cannot work; less crops grown so less income for farmers / higher prices so cannot afford; 2(e)(ii) any two from: 2 limited or no irrigation; unreliable water supply / water available at wrong time for crop growth; water needed for plant growth / for photosynthesis / grow crops; less feed grown for livestock / livestock don’t survive so less meat or dairy production;

Question 17

(a) A conservationist investigates the population of beetles in five different locations in Italy, Europe. Table 5.1 shows the results. Tab…

Accepted Answer

5(a) axis labels: y-axis number of (species of) beetles AND x-axis location; 4 sensible linear scale to cover at least half of grid; bars equal width and not touching; 4–5 correct plots; 5(b)(i) 50; 1 5(b)(ii) the area sample / quadrat is representative (of whole area); 2 scale up from quadrat to whole area / multiple by number of quadrats; 5(b)(iii) any one inconsistency in: 1 counting individual beetles on the edge of the quadrat / different counting methods (between two people); ability to ‘see’ the beetles; misclassification e.g. between woodlouse and beetle; 5(b)(iv) sweep net / pitfall trap; 1 tree/bush shaking with sheet / beating tray under the tree to collect beetles; 5(c) too large / larger / big; 2 fast moving / move around a lot / constantly moving; 5(d) any two from: 2 biased / subjective / not accurate; qualitative method / non-quantitative; over-estimations of conspicuous plants or plants in flower / underestimation of inconspicuous plants; some species can be confused with others; 5(e) higher percentage of population loss for A; 2 comparative quoted data: A = 10% / B = 5% 5(f) any two from: 2 maintains resources / named resources e.g. food, wood, medicines; diversity in genes; cultural value; recreational / tourism values; pollination; idea that it prevents extinction; 5(g)(i) eats producer / in the second trophic level; 1 5(g)(ii) reduced population; 2 as less food; 5(h) 10; 1

Question 18

(a) Spraying aerosols into the stratosphere and growing crops with shiny leaves are two geo-engineering methods that can counteract climate…

Accepted Answer

Question Answer Marks 1(a)(i) any two from: 2 reflect (incoming) solar radiation / (sun)light, back into space; before it reaches the Earth’s surface; reduces global temperatures; 1(a)(ii) any two from: 2 increases, albedo / reflectivity (of plants / Earth’s surface); reflect (incoming) solar radiation / (sun)light, back into space; reduces global temperatures; 1(b)(i) any two from: 2 changed (wind/atmospheric) circulation; adverse effect on rainfall / too much rain / too little rain; changed temperatures; more extreme weather conditions e.g. hurricanes / storms / heatwaves; 1(b)(ii) any two from: 2 Positives: both strategies reduce global temperatures; Negatives: both strategies cause adverse effects e.g. floods / drought; many people adversely impacted (due to floods / droughts) e.g. relocation; more people adversely impacted by spraying aerosols than growing crops with shiny leaves / 3 billion (aerosols) versus 1.4 billion (shiny leaves); but need to fix climate change regardless of cost; 1(b)(iii) any one from: 1 laboratory / small scale testing; field testing; repeat the (computer) models with different parameters e.g. measure, humidity / greenhouse gas concentration or named greenhouse gas; 1(c) axis labels: y-axis number of people / million AND x-axis country; 4 sensible linear scale to cover at least half the grid; bars equal width AND not touching; four or five correct plots; 1(d) any three from: 3 (flooding) contaminates / pollutes, water bodies; stated examples of contamination / pollution e.g. sewage / industrial waste / domestic waste / agricultural waste / fertilisers; water, cannot be drunk / is unsafe; (flooding can lead to) saltwater / seawater intrusion; damage to, infrastructure / distribution pipes / tanks (so distribution adversely affected); 1(e) any three from: 3 plants / crops, need water for growth; by photosynthesis; (lack of water) reduces crop yield / loss of crops / loss of livestock; leads to famine / starvation; leads to food insecurity; 1(f) any three from: 3 majority south of Tropic of Cancer; some north of Tropic of Cancer; between Tropic of Cancer and equator; underweight children in Africa / (South) Asia; relevant quoted country / data e.g. high in India or Indian sub-continent / low in Americas;

Question 19

Rice is the main food of three billion people and provides one fifth of the calories consumed globally. (a) Fig. 3.1 shows rice growing in …

Accepted Answer

3(a)(i) any three from: 3 methane / carbon dioxide, are greenhouse gases; leads to, global warming / climate change; (growing new varieties) reduces carbon footprint; rice eaten by very large number of people / rice is a staple food; (growing new varieties) mean less water used / increases water security; 3(a)(ii) any one from: 1 no need to irrigate; farmers familiar with this method / traditional method; terracing prevents soil erosion; can be grown on limited / poor quality soil; water contains nutrients; high yield (per unit area); 3(b)(i) any two from: 2 size / area (of field); soil type; soil pH; moisture content of field; salinity / soil fertility; 3(b)(ii) C AND lowest yield / mass per ha; 1 3(b)(iii) total max four: 4 any one from: random sampling described: sample sites selected using grid and use a random number generator; OR systematic sampling described: divide the field into grid / transects and select every nth square / transect; any two from: method of sweeping: walk slowly up/down rows or across field; sweep from side to side / sweep through 180; use one sweep per step; avoid thorns/sharp bushes; sweep upper part of plant; count the number of insects / average number of insects; any one from: method of stopping insects escaping: turn the net so opening is face down / hold net closed above contents; let bottom of net drape over edge of a frame (to trap insects in net); 3(b)(iv) any two from: 2 some insects, missed / escape; insects missed close to, soil / ground; difficult to use in, water / paddy field; does not work well in short or dense vegetation; net is easily damaged; time consuming / hard work; 3(b)(v) total max four: 4 max [3] advantages: effective / efficient; quicker method / less labour intensive; prevents decrease in crop yield; reduces chance of food insecurity; do not need to reintroduce a predator; biological control can become invasive; max [3] disadvantages: affects non-target species / soil organisms; affects pollinators; can become resistant to insecticide; can enter water bodies / can enter food chain / bioaccumulation described / biomagnification described; 3(b)(vi) N = 541; 4 grasshopper = 0.095 AND earwig = 0.182 AND aphid = 0.0079 AND thrip = 0.031;  n  2 = 0.316 / 0.32;     N  D = 0.684 / 0.68;

Question 20

(a) The UK government promotes the use of electric cars. Electric cars do not use fossil fuel to power them. In 2022, most of the electrici…

Accepted Answer

4(a) Total max five: 5 max [4] advantages: electric cars do not emit carbon dioxide; which is a greenhouse gas; less impact on, climate change / global warming / air pollution; lower running costs / cheaper or free parking / cheaper to maintain; subsidies for, purchasing car / installing charging; easier to get around in towns / can use bus lanes / no congestion charge; reduced noise pollution; max [4] disadvantages: electricity for charging comes from burning fossil fuels AND this releases CO2 / greenhouse gases; batteries made with energy from combusting fossil fuels / high amount of energy or raw materials (lithium) needed to produce batteries; (charging) infrastructure currently not widely available; contamination issue from disposal of batteries; short travel distance / short battery range / batteries do not last long (need repairs) / batteries take long time to charge; 4(b)(i) any one from: 1 get large amount of information; time consuming / difficult, to process answers; 4(b)(ii) 1 ; 4(c)(i) 62 000; 1 4(c)(ii) 42; 1 4(c)(iii) any two from: 2 percentage (of electric cars) takes into account the total number of cars; can compare between countries / shows the differences between countries; more accurate representation of the use of electric cars (in a country); 4(d)(i) any two from: 2 fossil fuel depletion; inequality in global energy resources; population growth; differing energy needs; climate change; delays or disruption in supply; reliance on imports; reliance on one form of energy; war / conflict; 4(d)(ii) any two from: 2 increased prices for, fuel / energy; increasing cost to industry; job losses; economic recession / decreased economic wealth / slowed economic growth / unstable economy; increased poverty / lower standards of living; reliance on price set by other countries (as energy imported);

Question 21

(a) A student investigates the concentration of nitrate ions in a lake. The student makes the following hypothesis: ‘The concentration of n…

Accepted Answer

2(a)(i) (air) temperature; 1 2(a)(ii) any one from: 1 volume / amount of water; collect water, in same way / at same depth; time of day / time of collection; location e.g. side of lake / position of sampling; 2(a)(iii) any two from: 2 results can be compared; anomalous results exclude / identifies anomalous results or outliers / identify mistakes; average/mean found; averaging/identifying anomalies increases accuracy; averaging reduces effect of random errors / reduces margin of error; confirm results / proves or disproves results; 2(b)(i) answer to one decimal place: 3.2; 2 unrounded answer: 3.16; 2(b)(ii) 16; 1 2(b)(iii) no; 1 AND any one from: valid evidence e.g. highest temperature and lowest concentration or correctly quoted data; no correlation (between air temperature and concentration of nitrate ions); 2(b)(iv) systematic sampling described e.g. every nth distance across lake selected; 1 2(b)(v) any one from: 1 data only gives information on nitrate; only five samples / not representative; may contain other pollutants / named pollutant; 2(c)(i) any three from: 3 nitrate concentrations (in wells) greatest in centre of state / towards middle / increases close to the state capital; cluster in southwest corner > 10.0 (mg /L ); between 3.0–10.0 (mg / L) in south east corner / between Wisconsin and Iowa; low concentrations along border with Lake Superior / in North / border with Canada; low concentrations around the state capital; 2(c)(ii) leaching; 1 2(d) any two from: 2 piped / from taps; aquifer; borehole; gravity-fed; reservoirs / dams; 2(e)(i) any two from: 2 people spend hours collecting water; cannot work / cannot earn money; cannot attend school / get an education; people drink contaminated water; people become ill (dehydrated / water-borne disease) so cannot work; less crops grown so less income for farmers / higher prices so cannot afford; 2(e)(ii) any two from: 2 limited or no irrigation; unreliable water supply / water available at wrong time for crop growth; water needed for plant growth / for photosynthesis / grow crops; less feed grown for livestock / livestock don’t survive so less meat or dairy production;

Question 22

(a) A conservationist investigates the population of beetles in five different locations in Italy, Europe. Table 5.1 shows the results. Tab…

Accepted Answer

5(a) axis labels: y-axis number of (species of) beetles AND x-axis location; 4 sensible linear scale to cover at least half of grid; bars equal width and not touching; 4–5 correct plots; 5(b)(i) 50; 1 5(b)(ii) the area sample / quadrat is representative (of whole area); 2 scale up from quadrat to whole area / multiple by number of quadrats; 5(b)(iii) any one inconsistency in: 1 counting individual beetles on the edge of the quadrat / different counting methods (between two people); ability to ‘see’ the beetles; misclassification e.g. between woodlouse and beetle; 5(b)(iv) sweep net / pitfall trap; 1 tree/bush shaking with sheet / beating tray under the tree to collect beetles; 5(c) too large / larger / big; 2 fast moving / move around a lot / constantly moving; 5(d) any two from: 2 biased / subjective / not accurate; qualitative method / non-quantitative; over-estimations of conspicuous plants or plants in flower / underestimation of inconspicuous plants; some species can be confused with others; 5(e) higher percentage of population loss for A; 2 comparative quoted data: A = 10% / B = 5% 5(f) any two from: 2 maintains resources / named resources e.g. food, wood, medicines; diversity in genes; cultural value; recreational / tourism values; pollination; idea that it prevents extinction; 5(g)(i) eats producer / in the second trophic level; 1 5(g)(ii) reduced population; 2 as less food; 5(h) 10; 1

Question 23

(a) Fig. 1.1 shows water usage by sector in the USA and Nigeria. Content removed due to copyright restrictions. Fig. 1.1 Suggest reasons fo…

Accepted Answer

1(a) any two from: comparative idea of different level of economy; Nigeria, recycles water / wastes less water / ora USA; Nigeria large(r) agriculture sector / economy based on agriculture / ora USA; Nigeria small(er) industry sector / less reliant on industrialisation / less industrialisation / less investment in industry / ora USA; idea of restrictions on water usage in stated sector AND country / ora; idea of more efficient appliances in stated sector AND country / ora; 2 1(b) any three from: causes illness or named illness / diarrhoea / cholera / named disease; cannot farm or work / leads to loss of earnings; time is needed to find clean drinking water; idea of cost of, buying clean water or treating water; idea of cost of medical treatment; idea of shortage of water leading to conflict; idea of contaminated water cannot be used to grow crops AND link to impact e.g. which then have to purchased or cannot be sold or food prices increase; idea of needing to move to a different area; 3 1(c) well that starts in surface layer and ends in either water layer; 1 Question Answer Marks 1(d) any two from: collects or uses rain water / rain water is recycled / rain water catchment / stores water; can be used for, irrigation / crops / washing clothes; reduces use of domestic water supply / reduces use of ground water; can be used for drinking water after treatment; water can be used during a drought; idea of lower cost as not buying treated water or paying for water; 2 1(e) ice sheets / glaciers / lakes / rivers / permafrost; 1 1(f) axes labelled with unit for y-axis: x-axis: year AND y-axis: (mean) concentration AND (arbitrary) units; sensible linear scale for both axes with plotted points that cover at least half of grid; 89 plots correct; all 10 plots correct; straight line drawn with ruler between each point AND not extrapolated back to zero or beyond year 10; 5

Question 24

(a) In 2022, 80% of the timber used in the UK was imported. (i) Suggest one negative impact for the UK of importing timber. ...............…

Accepted Answer

2(a)(i) any one from: prices can be increased (by other country); lack of self-reliance / reliance on other countries / idea of imbalance of supply and demand; not sustainable; stated economic impact (e.g. cost of transport / cost of importing / impact on UK timber industry; energy use of transport or using vehicles / transport has carbon footprint / atmospheric impact of use of transport / named air pollution linked to transport; may introduce, invasive species / disease; 1 2(a)(ii) any two or one developed from: livestock cannot graze on land / less space for livestock; food or crops, not grown or less grown / less yield or less space for food or crops; leads to food insecurity; long lead time / timber harvest will not be available for many years / trees take a long time to grow; 2 2(b) reference to (trees) photosynthesise; trees remove or store, carbon dioxide / carbon dioxide reactant (in photosynthesis) / carbon dioxide  water (→ glucose  oxygen); 2 Question Answer Marks 2(c) any three from: road separates or fragments the forest or habitat / one side of the forest is cut off by a road / road separates animals or organisms; power lines / pylons, separate or fragment forest / pylons separate animals or organisms; no access to the lake / animals have to cross the road to reach the lake; loss of trees at edges or barren land around edges of forest or edges road; 3 2(d)(i) idea of most in, (north) Scotland / north / few in England AND Wales; any one from population: dispersed / scattered / spread out; more along coast / more west (Wales) / few in east / few in central England or in centre / cluster south (England); 2 2(d)(ii) any three from: public are not experts / misidentification / wrong species counted; bees, may be missed / counted more than once / move around / difficult to see / difficult to get close to / miscounting / inputted incorrectly / counting errors / error in remembering number counted; no details on how the sightings were made e.g. random / systematic / stated conditions e.g. weather, temperature; some areas give more or less returns / no information on number of people reporting / no information on number of bees; difficulty in finding map grid reference / location may not be correct / wrong grid; need access to, smartphone / computer / internet; 3 Question Answer Marks 2(e) for max [4] at least one from each section (method, repeat, estimation) plus any other marking point: method: count the bees observed / count bees (along transect or line); within stated distance either side or along transect or line; e.g. 2 m repeat: repeat at different times (of day / year); repeat complete investigation AND average; estimation: idea of scaling up e.g. determine number of bees in 1 m or 1 m2 and multiply by total area; 4 Question Answer Marks 2(f) any five from: artificial hives / ORA natural nests: bees may not adapt to artificial hives / hives might not be suitable to bees’ needs; quality or quantity of honey may be different / different productivity in artificial hives; idea of cost of artificial hives; conditions controlled; bees can be, fed / given water; hives can be cleaned; disease can be treated; easier to collect honey / hive in convenient location / ease of maintenance or monitoring (for beekeeper); can hold larger population / hives are larger than nests / fixed size; last longer / more durable; protects from predators; sun hive: tree or location same as nest / location is in natural habitat; similar shape to natural nest; can get blown away / damaged by wind or weather / at risk due to deforestation; wooden hive: easier to monitor at ground level; wood destroyed by termites / wood rots; AVP; 5 2(g) any three from: (out)compete for, habitat / nesting sites / shelter / territory; (out)compete for stated resources e.g. food / disrupt food chain; carry disease; breed quicker (than bees); predators of bees / prey on bees; no known predators (for hornets); 3

Question 25

Methane is an atmospheric pollutant. (a) Fig. 3.1 shows the concentration of methane gas in the atmosphere from 1983 to 2022. 1950 1900 185…

Accepted Answer

3(a)(i) any two from: methane is a greenhouse gas / increase in greenhouse gases; (increase in enhanced) greenhouse effect; increase (global) temperature / climate change; 2 3(a)(ii) any two from: rice fields or paddies; livestock or named livestock (digestion); landfill; decomposition of vegetation / rotting of vegetation; released from melting permafrost; peat (bogs) / wetlands; mining / rock extraction / fracking; 2 3(b)(i) successful because: emissions decreased; no areas greater than 18 000 tonnes (in 2020) / idea of reduction in emissions in east / no 270 000 tonne emissions in 2020 less successful because: increase in emissions on west (coast); 3 3(b)(ii) (in the atmosphere SO2) reacts with (rain)water (and oxygen); forms sulfuric acid; 2 3(b)(iii) wet acid deposition: snow / rain / hail / fog; dry acid deposition: dust / gas(es); 2 Question Answer Marks 3(b)(iv) any three from or developed responses: use of renewable resources / stated example e.g. solar; fuel desulfurisation; flue gas desulfurisation; description gases dissolved in water; neutralised/reacted/removed with limestone or calcium carbonate or CaCO3; electrostatic removal (from emissions); catalytic convertors; restricting vehicle use / electric cars or EVs / use public transport / car pooling / idea of encouraging walking or cycling; international agreements / legislation / clean air zones / limits on emissions from factories; polluter pays principle / fines; idea of education or raising awareness; 3 3(c)(i) keep soil the same / same consistency / same composition / even distribution (of nutrients or particles or minerals); 1 3(c)(ii) any one from: pH of non-acid deposition; compare results with non-acid rain; control; 1 3(c)(iii) pH (of water); 1 3(c)(iv) identify anomalous result or outlier / trend can be identified / reduce impact of anomalous results / determine a mean; 1 3(c)(v) fair test / results are comparable / amount of water in each leaf is variable (in different plants or leaves); 1 Question Answer Marks 3(c)(vi) any one from: acid precipitation reduces crop yield; the lower the pH the lower the yield; the more acidic the pH the lower the yield / ORA; the greatest reduction in yield was for pH 3.0; highest yield at pH 6.0 / higher pH gives higher yield; 1 3(c)(vii) 10.92; 1 3(c)(viii) any one from: pH 3.5 and lower damages leaves; pH 4.0 and higher does not damage leaves; the more acidic / the lower the pH, the more damage / ORA; pH 3.0 / lowest pH, causes most damage; damage increases as pH decreases; 1

Question 26

(a) Scientists use tree ring data to investigate tree growth in a local area. Each year a tree grows, a new tree ring forms. Wider tree rin…

Accepted Answer

2(a)(i) max two justifications: year 0 to 20: higher than average tree ring width; year 50 to 80: higher than average tree ring width; idea of significant fluctuations; max two conclusion: (no impact from factory because) more years with higher than average tree ring width / more years with above average growth; other factors impact tree growth / factor named e.g. drought / fire / temperature / disease; 2(a)(ii) ice cores; historical accounts; 2 2(b)(i) any two from: for both concentrations mass increases with time; increased ozone concentration decreases plant mass / the longer the plants are exposed to ozone the greater the difference in mass between 20 and 120 ppm; little effect in first year; relevant quoted comparative data e.g. after 3 years 25 g different; 2 2(b)(ii) any three from: total number of plants; species of plant; stated growing conditions ;;; e.g. soil pH, amount of light, volume of water, spacing, temperature, organic content of soil AVP; 3 2(c)(i) troposphere; 1 2(c)(ii) in the presence of sunlight; any two from reaction of ozone with: oxides of nitrogen ; particulates; volatile organic compounds / VOCs; 3 Question Answer Marks 2(c)(iii) any two from: eye irritation; respiratory irritation; 2 2(d)(i) axes labelled with units; time / hour AND concentration / ppm sensible linear scale with plotted points that cover at least half of grid; plotting 78 correct; plotting all 9 correct; straight line drawn with ruler between each point connecting AND not extrapolated beyond 24 hours; 5 2(d)(ii) 0.82; 1 2(d)(iii) no AND any one from: do not know concentration between hours 1518; data is not repeated; concentration at 15 could be anomalous; 1

Question 27

(a) Fig. 3.1 shows the European bee‑eater bird. Fig. 3.1 A scientist investigates whether the number of European bee‑eaters can be predicte…

Accepted Answer

3(a)(i) to get representative data; 1 3(a)(ii) anomalous result circled; 1 3(a)(iii) any one from: (number of birds can be predicted using sound recordings because) songs per minute increases as number of birds increases; positive correlation between number of birds and songs per minute; 1 Question Answer Marks 3(a)(iv) any two from: time consuming / 3 days of recordings to listen to; difficult to identify the song of the European bee-eaters compared to other birds; other sounds other than birds might interfere with the recording; birds all singing at once; same bird could be counted more than once; AVP; 2 3(a)(v) any one from: birds not disturbed; recordings can be left for a long time to run / automated; idea of permanent record / data can be checked; big data that can be analysed by computer; eliminates error if analysed by computer; AVP; 1 3(b)(i) (250  235)  124 / 473.79; 474; 2 3(b)(ii) decreases AND any one from: lower proportion of marked birds in total population; greater mixing of marked released birds with total population; lower recapture of marked birds in second sample; 1 3(c)(i) any three from: reintroducing species; reducing active management of wildlife; allowing natural forest regeneration; idea of letting nature manage itself / idea an area reverts back to natural state; 3 Question Answer Marks 3(c)(ii) any two from: decrease in competition; decrease in predation; more food; ban on hunting; climatic conditions; (seasonal) migration; AVP; 2 3

Question 28

(a) Fig. 3.1 shows the European bee‑eater bird. Fig. 3.1 A scientist investigates whether the number of European bee‑eaters can be predicte…

Accepted Answer

3(a)(i) to get representative data; 1 3(a)(ii) anomalous result circled; 1 3(a)(iii) any one from: (number of birds can be predicted using sound recordings because) songs per minute increases as number of birds increases; positive correlation between number of birds and songs per minute; 1 Question Answer Marks 3(a)(iv) any two from: time consuming / 3 days of recordings to listen to; difficult to identify the song of the European bee-eaters compared to other birds; other sounds other than birds might interfere with the recording; birds all singing at once; same bird could be counted more than once; AVP; 2 3(a)(v) any one from: birds not disturbed; recordings can be left for a long time to run / automated; idea of permanent record / data can be checked; big data that can be analysed by computer; eliminates error if analysed by computer; AVP; 1 3(b)(i) (250  235)  124 / 473.79; 474; 2 3(b)(ii) decreases AND any one from: lower proportion of marked birds in total population; greater mixing of marked released birds with total population; lower recapture of marked birds in second sample; 1 3(c)(i) any three from: reintroducing species; reducing active management of wildlife; allowing natural forest regeneration; idea of letting nature manage itself / idea an area reverts back to natural state; 3 Question Answer Marks 3(c)(ii) any two from: decrease in competition; decrease in predation; more food; ban on hunting; climatic conditions; (seasonal) migration; AVP; 2 3

Question 29

(a) ‘Climate TRACE’ is a global organisation that collects and shares data on greenhouse gas emissions from human activities. (i) Table 2.1…

Accepted Answer

2(a)(i) axis labels: y-axis and unit carbon dioxide emissions / billion tonnes and x-axis sector; 4 sensible linear scale with data that occupies at least half the grid; bars equal width and not touching; correct plots; 2(a)(ii) any three from: 3 provides reliable data; provides a large quantity of data / big data; increases confidence in data; predicts emissions where data is not available; data can be used in climate models; shows which sectors are most polluting; targeted strategies for each sector; increase (public) awareness; idea that it is a global organisation so includes all countries / produces global averages for emissions; 2(b)(i) correct readings from graph: 3 2015: 7.11 and 2020: 6.85; correct manipulation of 2015 and 2020 data; [(7.11 − 6.85)  7.11]  100 3.6568; answer to three significant figures (−)3.66; 2(b)(ii) any two from: 2 decreased use of vehicles; increase use of: public transport; electric cars; biofuel; low-carbon fuels; 2(c) any four from: 4 landfill sites; incineration / burning (of waste); storage; exporting to other countries; recycling; 2(d)(i) any two from: 2 chicken litter content are plant based; plants took in carbon dioxide (during photosynthesis); this carbon dioxide is returned to the atmosphere; 2(d)(ii) biomass / biofuel; 1 2(d)(iii) any two from: 2 could become invasive / could outcompete native plants; replace food crops / use land that could be used for agriculture or crops; could lead to food insecurity; (grown for biofuel so) short lived habitat; reduces biodiversity; require a lot of water;

Question 30

(a) Bats are flying nocturnal mammals. They are active at night time and feed on insects. Fig. 2.1 shows a bat. This species of bat has a w…

Accepted Answer

2(a)(i) idea of a comparison with a control / identify anomalous results; 1 2(a)(ii) No and peak bat activity has low insect numbers / ORA; 1 2(a)(iii) data is only for bat activity / no information on number of bats / same bat could be counted numerous times or not counted 1 at all; 2(b) any two from: 2 fit tracking devices to the bats; monitor by GPS; use radio tracking; put electronic (motion) detectors at different distances from the cave; 2(c) any three from: 3 international agreement or cooperation; to ensure international trade in bats does not threaten the survival of the species / cause extinction; prevents illegal trade / poaching; provides information / updates on endangered status of species; raise awareness / education (of bats); 2(d) max four: 4 max three benefits: quicker than using other methods e.g. sweep net; a lot of insects collected; low skill level needed to operate; could survey a wide area; max three limitations: cost of equipment; insects may be killed or harmed; only collects insects where suction device is pointed; equipment might be heavy to use; requires fuel or battery (unlike a sweep net);

Question 31

Gold is a valuable metal. (a) Mercury, Hg, is used to extract gold in small-scale gold mining. Mercury is mixed with gold-containing minera…

Accepted Answer

3(a) any four from: 4 dissolves in water in the atmosphere; falls as wet deposition, e.g. snow, rain, hail, fog; absorbed by dust or gases; falls as dry deposition; intercepted by leaves on trees; leaves fall onto soil as litter; 3(b) axis labels: y-axis and unit (mercury) concentration / g per g and x-axis country; 4 sensible linear scale with data that occupies at least half the grid; bars equal width and not touching; 4–5 correct plotting; 3(c) any four from: 4 road built through the forest; deforestation; fragmentation; leaching from ponds; water or soil pollution; piles of waste / overburden; (leading to) habitat loss; loss of biodiversity / food chain disruption; atmospheric pollution from vehicles / machinery; 3(d)(i) any two from: 2 those who produce the pollution should pay (for the cost of managing its impacts); implemented through taxation or fines; incentive not to pollute; 3(d)(ii) any two from: 2 gold mine is illegal; polluter may refuse to pay; difficulty in finding the polluter; difficulty in monitoring the pollution; not all countries agree to the principle; difficult to measure the amount of pollution made particularly if it is a gas; money collected from polluters could be spent elsewhere / not on this location affected by mining; 3(e)(i) ability to meet the needs of the present; 2 without compromising the ability of future generations to meet their own needs; 3(e)(ii) any two from: 2 licences for extraction; quotas for extraction; recycle / reuse / reduce; limits on export; charge high prices for gold;

Question 32

(a) ‘Climate TRACE’ is a global organisation that collects and shares data on greenhouse gas emissions from human activities. (i) Table 2.1…

Accepted Answer

2(a)(i) axis labels: y-axis and unit carbon dioxide emissions / billion tonnes and x-axis sector; 4 sensible linear scale with data that occupies at least half the grid; bars equal width and not touching; correct plots; 2(a)(ii) any three from: 3 provides reliable data; provides a large quantity of data / big data; increases confidence in data; predicts emissions where data is not available; data can be used in climate models; shows which sectors are most polluting; targeted strategies for each sector; increase (public) awareness; idea that it is a global organisation so includes all countries / produces global averages for emissions; 2(b)(i) correct readings from graph: 3 2015: 7.11 and 2020: 6.85; correct manipulation of 2015 and 2020 data; [(7.11 − 6.85)  7.11]  100 3.6568; answer to three significant figures (−)3.66; 2(b)(ii) any two from: 2 decreased use of vehicles; increase use of: public transport; electric cars; biofuel; low-carbon fuels; 2(c) any four from: 4 landfill sites; incineration / burning (of waste); storage; exporting to other countries; recycling; 2(d)(i) any two from: 2 chicken litter content are plant based; plants took in carbon dioxide (during photosynthesis); this carbon dioxide is returned to the atmosphere; 2(d)(ii) biomass / biofuel; 1 2(d)(iii) any two from: 2 could become invasive / could outcompete native plants; replace food crops / use land that could be used for agriculture or crops; could lead to food insecurity; (grown for biofuel so) short lived habitat; reduces biodiversity; require a lot of water;

Question 33

(a) A farmer investigates insect pests on soybean plants. Fig. 3.1 shows soybean plants. Fig. 3.1 The farmer investigates an area of soybea…

Accepted Answer

3(a)(i) 3 plants circled correctly at 32, 60, 53; 1 3(a)(ii) avoids bias / equal chance of selection; 1 3(b)(i) method: 5 (on one plant) tap / hit / shake the plant (gently with a stick); collect falling insects on the beating tray; count (only) the insects; processing: repeat (the beating tray) method and take a mean; idea of scaling up; e.g. multiply the mean number of insects in the sampled area / plants sampled by the total number of plants 3(b)(ii) any two from: 2 soybean plants are close to ground so difficult to get lower insects in tray; beating can damage the plant; beating cannot be used on wet plants; flying insects fly away / some insects might escape; some insects left on plant / not all insects will fall on the tray; 3(c)(i) biological; 1 3(c)(ii) control / to compare the result; 1 3(c)(iii) any one from: 1 to ensure that field 1 and field 2 had a comparable number of aphids (at the start); to see if the predator has an effect; 3(c)(iv) predator reduces the aphid population; 3 predator takes 8–12 days to make an impact / it took 10 days for the introduced predator to work; relevant comparable quoted data e.g. difference in aphid population with no predator is 215 (255-40) by day 65; 3(c)(v) any two from: 2 prevents predator flying away; prevents new pests / insects landing on the plants; prevents new predators landing on the plants; (so that the farmer knows) it is the harlequin beetle predator that has reduced the aphid population; 3(d) any one from: 1 increased temperatures mean it will not become inactive; native species may die at hotter temperatures / in changed conditions; beetle competitors / predators might die; expand range of beetle; 3(e)(i) plants grown at high density / high crop yield (per unit area); 4 any three from: plants grown without soil / roots are in water that contains nutrients; plants less prone to soil pests; plants can be grown in areas with soil erosion / poor quality soil; plants can be grown inside; plants can be grown in controlled conditions; e.g. controlled lighting yields not dependent on weather conditions / rainfall; crops are not seasonal / can be grown all year; 3(e)(ii) any three from: 3 leads to food shortages; more likely to benefit rich; food could rot if not stored properly; danger of losing (large) quantity of food at one time; fresh food loses nutritional value if stored for long period; idea that food should be distributed to people who are hungry now; 3(e)(iii) any four from: 4 food scarcity; nutritional deficiency / malnutrition; famine / starvation; poverty; forces migration; conflict;

Question 34

Water turbidity measures the cloudiness of water. Turbidity is caused by undissolved solids in water. (a) A student uses a Secchi disc to m…

Accepted Answer

2(a)(i) 1.70; 1 2(a)(ii) any two from: 2 M1 wind / rain / floods / storms, stir up the water / disturb sediments / increase turbulence / change turbidity / reduces visibility (in water); M2 wind or storms, cord will not be vertical / cord will move / difficult to read; M3 wind or storms, cord or disc gets damaged / broken; M4 waves / not flat water / not calm water, difficult to read the cord / make depth variable; M5 (long period of) rain can, water levels that fluctuate / give variable depths; M6 lack of sunlight / cloudy / foggy / overcast / dull day, reduces visibility or difficult to see disc or cord; M7 high sunlight causes glare; M8 cold temperatures water could be frozen; M9 temperature changes particle distribution; M10 safety idea about going on water when bad weather; 2(a)(iii) any two from: 2 M1 identifies outliers / anomalous results excluded; M2 results can be compared; M3 mean found; M4 get representative data / increases sample size; 2(b)(i) Sun; 1 2(b)(ii) any two from: 2 M1 producers / phytoplankton/plants, contain chlorophyll; M2 as chlorophyll (concentration) increases (population of) producers increase / chlorophyll needed for photosynthesis; M3 higher chlorophyll (concentration) gives greater primary production / (primary) productivity; 2(c) any one from: 1 M1 as (Secchi) depth decreases chlorophyll or concentration increases / ORA; M2 higher the chlorophyll or higher concentration the lower the (Secchi) depth; 2(d)(i) total max four: 4 max three benefits: M1 cheap / costs less; M2 large quantity of data provided; M3 data can be collected from inaccessible areas / (scientist) don’t have to travel to all places; M4 representative data / global data; M5 quicker (for scientists) / saves (scientist) time; max three limitations: M6 big data / problem of analysing large quantity of data; M7 who owns the data rights; M8 amateurs / non-scientists / non-professionals, collecting data; M9 cannot verify or confirm data / no information about how data collected / subjective / potential for errors / misinterpretation / wrong information; M10 may only come from one areas / some areas not covered; M11 not everyone has access to website; 2(d)(ii) any three from: 3 M1 seas too warm / temperature of sea increases; M2 photosynthesis reduced; (rising temperatures cause): M3 change in salinity; M4 increased carbon dioxide concentrations; M5 ocean acidification / decrease in water pH; M6 change in ocean, circulation / currents; M7 phytoplankton cannot adjust to changed conditions; M8 increased risk of invasive species; M9 change in migration of organisms that consume phytoplankton; M10 more extreme weather / storms, increase turbidity (reducing photosynthesis); 2(e)(i) 4; 1 2(e)(ii) 29; 1 2(f) any two from: 2 M1 reduced growth (rates); M2 delayed or less, hatching (rates); M3 feeding stress / reduced feeding (rate) / reduced feeding success;

Question 35

(a) A questionnaire is used to obtain the opinions of people in different regions on the importance of recycling. Fig. 1.1 shows the result…

Accepted Answer

Question Answer Marks 1(a) any three from: 3 MP1 most people in all regions view recycling as extremely important; MP2 Africa has highest percentage; MP3 Oceania has lowest percentage; MP4 comparative data quote e.g. Europe is greater than North America; 1(b)(i) any two from: 2 benefits (max 1): MP1 limits (detailed / explained) responses; MP2 easy to answer; MP3 quick to analyse; MP4 quantifiable; limitations (max 1): MP5 no category for, ‘do not know’ / no opinion / no personal response; MP6 limits detail in answers / does not allow for detailed answers; MP7 difficult to choose between the categories; 1(b)(ii) any one from: 1 MP1 representative sample; MP2 large sample; MP3 reduces bias; 1(c) any three from: 3 MP1 lack of facilities; MP2 lack of understanding of what can be recycled; MP3 lack of trust in recycling programmes; MP4 inconvenience / time consuming; MP5 lack of government support / legislation; MP6 existing waste disposal methods; 1(d)(i) any four stated or developed: 4 MP1 does not biodegrade; MP2 can be ingested by marine life / cause choking to marine life; MP3 can entangle marine life; MP4 risk of suffocation; MP5 form microplastics; MP6 bioaccumulation; MP7 bioaccumulation described; e.g. build-up of toxins within an organism / ingested faster than can excreted; MP8 biomagnification; MP9 biomagnification described: e.g. increase in concentration of pollutants up the food chain; 1(d)(ii) any two from plastic fibres: 2 MP1 can reduce land required for crops / land can be used to grow food instead; MP2 water not needed to water a crop; MP3 a method of recycling or disposing of plastic; MP4 reduces the plastic waste in the ocean; MP5 uses less energy; MP6 less CO2 produced; 1(e) any four from: 4 benefits (max 3): MP1 reduces quantity of waste / reduces waste in landfill; MP2 quick method; MP3 small area of land needed; MP4 heat generated can be used to heat homes or produce electricity / energy dense; MP5 safely disposes of plastics that are contaminated; limitations (max 3): MP6 produces toxic substances / air pollution; MP7 named example: e.g. particulates / acidic gases / NOx / CO2; MP8 stated impact or air pollution e.g. acid rain / global warming / respiratory problems / impact on crop yield; MP9 smell; MP10 need specialist equipment e.g. tall chimneys; MP11 (high) energy requirement;

Question 36

Fig. 2.1 shows a ghost swift moth. Moths are flying insects. 5 cm Fig. 2.1 (a) ‘Moth Night’ is an initiative for the public to record infor…

Accepted Answer

2(a)(i) any one from: 1 MP1 not everyone knows the species of moth; MP2 public are not experts in identifying moths; 2(a)(ii) so results across the country can be compared (for different weather conditions); 1 2(b)(i) MP1 light attracts moths; 2 MP2 fall into container; 2(b)(ii) to prevent dehydration (of moths) / for moths to drink; 1 2(b)(iii) any two from: 2 MP1 species other than moths are collected; MP2 only attracts moths active at night; MP3 uses electricity / energy (which is expensive); MP4 non-target species may eat moths; MP5 moths may get killed by flying too close to light; MP6 difficult to use in wet/windy conditions; 2(c)(i) 420; 1 2(c)(ii) any two from: 2 MP1 fluctuating population; MP2 overall decline from year 1 to year 50; MP3 population starts to recover after 32 years; MP4 difficult to determine if moth population declining, requires more data / time ; 2(d)(i) any three from: 3 MP1 increase crop yield / number of fruit on tree; MP2 increase profit; MP3 max two examples of how profit can be used to increase food security e.g. reinvest in seeds / new crops / machinery;; MP4 MP1 leads to lower food prices; 2(d)(ii) any two from: 2 MP1 25–49% / 10–24% are most frequent; MP2 most dependent crops are within the tropics; MP3 relevant quoted data e.g. North America is 10–24% ; 2(e) MP1 plant as first trophic level and four trophic levels total; 2 MP2 arrows pointing correctly; plant → moth → bluetit → owl 2(f) any two from: 2 MP1 shows the total number of individual organisms at each, food chain level / trophic level; MP2 does not take into account biomass of (organisms); MP3 top level may be parasites; MP4 small number of producers could support larger number of smaller consumers / ORA;

Question 37

An increase in wild fires is an impact of climate change. (a) Explain how climate change leads to wild fires. .............................…

Accepted Answer

3(a) any three from: 3 MP1 higher temperatures; MP2 drought; MP3 less rainfall; MP4 vegetation drier; 3(b)(i) MP1 axes labels e.g. y-axis label: number of (recorded) wild fires AND x-axis: year; 4 MP2 sensible linear scale, plotted points occupy half the grid; MP3 6–7 bars of correct height; MP4 bars drawn with a ruler and equal width and not touching; 3(b)(ii) any one from: 1 not all fires reported; AVP; 3(c) any three from: 3 MP1 global warming / increased temperatures; MP2 more evaporation; MP3 more convection; MP4 more moisture to form clouds; 3(d)(i) any one from: 1 MP1 lower value (than 2000 value); MP2 (from 1900 to 2000) gradually increasing; 3(d)(ii) any two from: 2 MP1 based on different theories / policies; MP2 different data used / stated example e.g. temperature; MP3 biased data; MP4 improved or different technology / knowledge; 3(e)(i) any one from: 1 MP1 increased temperatures can melt ice; MP2 many research bases on ice shelfs; MP3 loss of habitat / loss of biodiversity; 3(e)(ii) any three from: 3 MP1 Antarctic Treaty / legislation / international agreement; MP2 people not allowed to enter protected areas / restricted activities; MP3 waste management / waste taken away from Antarctica; MP4 permits for travel; MP5 guides required; MP6 restriction of tourist / ship numbers;

Question 38

(a) A questionnaire is used to obtain the opinions of people in different regions on the importance of recycling. Fig. 1.1 shows the result…

Accepted Answer

Question Answer Marks 1(a) any three from: 3 MP1 most people in all regions view recycling as extremely important; MP2 Africa has highest percentage; MP3 Oceania has lowest percentage; MP4 comparative data quote e.g. Europe is greater than North America; 1(b)(i) any two from: 2 benefits (max 1): MP1 limits (detailed / explained) responses; MP2 easy to answer; MP3 quick to analyse; MP4 quantifiable; limitations (max 1): MP5 no category for, ‘do not know’ / no opinion / no personal response; MP6 limits detail in answers / does not allow for detailed answers; MP7 difficult to choose between the categories; 1(b)(ii) any one from: 1 MP1 representative sample; MP2 large sample; MP3 reduces bias; 1(c) any three from: 3 MP1 lack of facilities; MP2 lack of understanding of what can be recycled; MP3 lack of trust in recycling programmes; MP4 inconvenience / time consuming; MP5 lack of government support / legislation; MP6 existing waste disposal methods; 1(d)(i) any four stated or developed: 4 MP1 does not biodegrade; MP2 can be ingested by marine life / cause choking to marine life; MP3 can entangle marine life; MP4 risk of suffocation; MP5 form microplastics; MP6 bioaccumulation; MP7 bioaccumulation described; e.g. build-up of toxins within an organism / ingested faster than can excreted; MP8 biomagnification; MP9 biomagnification described: e.g. increase in concentration of pollutants up the food chain; 1(d)(ii) any two from plastic fibres: 2 MP1 can reduce land required for crops / land can be used to grow food instead; MP2 water not needed to water a crop; MP3 a method of recycling or disposing of plastic; MP4 reduces the plastic waste in the ocean; MP5 uses less energy; MP6 less CO2 produced; 1(e) any four from: 4 benefits (max 3): MP1 reduces quantity of waste / reduces waste in landfill; MP2 quick method; MP3 small area of land needed; MP4 heat generated can be used to heat homes or produce electricity / energy dense; MP5 safely disposes of plastics that are contaminated; limitations (max 3): MP6 produces toxic substances / air pollution; MP7 named example: e.g. particulates / acidic gases / NOx / CO2; MP8 stated impact or air pollution e.g. acid rain / global warming / respiratory problems / impact on crop yield; MP9 smell; MP10 need specialist equipment e.g. tall chimneys; MP11 (high) energy requirement;

Question 39

An increase in wild fires is an impact of climate change. (a) Explain how climate change leads to wild fires. .............................…

Accepted Answer

3(a) any three from: 3 MP1 higher temperatures; MP2 drought; MP3 less rainfall; MP4 vegetation drier; 3(b)(i) MP1 axes labels e.g. y-axis label: number of (recorded) wild fires AND x-axis: year; 4 MP2 sensible linear scale, plotted points occupy half the grid; MP3 6–7 bars of correct height; MP4 bars drawn with a ruler and equal width and not touching; 3(b)(ii) any one from: 1 not all fires reported; AVP; 3(c) any three from: 3 MP1 global warming / increased temperatures; MP2 more evaporation; MP3 more convection; MP4 more moisture to form clouds; 3(d)(i) any one from: 1 MP1 lower value (than 2000 value); MP2 (from 1900 to 2000) gradually increasing; 3(d)(ii) any two from: 2 MP1 based on different theories / policies; MP2 different data used / stated example e.g. temperature; MP3 biased data; MP4 improved or different technology / knowledge; 3(e)(i) any one from: 1 MP1 increased temperatures can melt ice; MP2 many research bases on ice shelfs; MP3 loss of habitat / loss of biodiversity; 3(e)(ii) any three from: 3 MP1 Antarctic Treaty / legislation / international agreement; MP2 people not allowed to enter protected areas / restricted activities; MP3 waste management / waste taken away from Antarctica; MP4 permits for travel; MP5 guides required; MP6 restriction of tourist / ship numbers;

Question 40

Rhinoceros are at risk from climate change. (a) A scientist uses capture-mark-recapture to record the number of rhinoceros in an area. (i) …

Accepted Answer

2(a)(i) any one from: 1 M1 may stress or frighten the animals; M2 increased risk of predation; M3 reduces chance of breeding success; M4 time consuming; 2(a)(ii) n1 (total) number of individuals captured in first sample; 3 n2 number of individuals captured in second sample both marked and unmarked; m2 number of marked individuals recaptured in second sample; 2(b) any three from: 3 M1 (only) continent of Africa; M2 highest in south(east) of Africa / mostly southern tip of continent; M3 (highest in) region of Tropic of Capricorn (in Africa) / mostly south of Equator / mostly southern hemisphere; M4 relevant quoted data; e.g. 1001–2500 in South of Africa 2(c)(i) 1970–1975 circled; 1 2(c)(ii) any three from: 3 M1 national park created; M2 hunting or poaching ban; M3 patrols / surveillance; M4 international protection e.g. IUCN red list; M5 increased awareness / education (on conservation); M6 captive breeding programme; 2(d)(i) March / Mar; 1 2(d)(ii) 10; 1 2(d)(iii) any three from: 3 M1 high rainfall; M2 high temperatures bake soil; M3 ground cannot absorb water; M4 leads to flooding; M5 climate change leads to extreme weather; 2(d)(iv) provides place to avoid (flood)water / mounds provide high ground; 1 2(d)(v) any two from: 2 M1 predation; M2 hunting / poaching; M3 competition for named resource, e.g., food / water / shelter / space; M4 disease / pests;

Question 41

(a) Fig. 5.1 shows the ‘Firelight Toilet’ system. Content removed due to copyright restrictions. Fig. 5.1 The system heats and dries toilet…

Accepted Answer

5(a)(i) any three from: 3 treated toilet waste: M1 better sanitation / reduces risk of diseases / reduces risk of contamination of water sources; M2 named disease or illness e.g. diarrhoea / cholera / dysentery; clean water produced: M3 clean water can be used for named purpose; e.g., irrigation / household use closed system: M4 reduces risk of leakage into water sources; M5 reduces open defecation (prevents water contamination); M6 water (for flushing), is produced from toilet waste / is recycled; M7 less water is used; 5(a)(ii) any two from: 2 M1 provides source of electricity or energy; M2 no chemicals added to toilet (which could contaminate water sources); M3 no pit needs to be dug to store waste; M4 ash can be used as a fertiliser; 5(b) any two from: 2 M1 water demand in increasing; M2 water availability is decreasing; M3 rate of increase and decrease the same; M4 demand exceeds availability in or after 2040; 5(c)(i) M1 axes labels and units: volume of water / billion m3 and all years indicated / year; 3 M2 suitable linear scale whereby plotted data occupies at least half the grid; M3 5 correct plots; 5(c)(ii) any two from: 2 M1 data is for, USA / one country; M2 not all countries are HICs; M3 differing, amounts of industrialisation or needs between rural and urban areas; M4 no data after 2010; M5 unpredictable events (may change industry usage by 2030); 5(d) any three from: 3 M1 improved irrigation / named improvement e.g. trickle drip; M2 growing crops less dependent on high water supply / GM modified drought resistant crops; M3 recycling water; M4 rainwater catchment; M5 mulching / covering soil (to reduce evaporation); M6 wind breaks (to reduce evaporation); M7 limits on water volume (legally) allowed to be used / legislation; 5(e) ground water and permafrost 2nd and 3rd box ticked; 1 5(f) any four from: 4 M1 water source or intake uphill from village; M2 idea of small dam that raises water level locally; M3 idea of source protected from contamination e.g. limited agriculture / no housing; M4 settlement tank / sediments or solids fall to bottom of a tank; M5 pressure break tank; M6 pipes to village; M7 idea of water treatment; e.g. add iodine tablets / chlorination / storage tank / water stand posts / taps M8 not all water taken from source (to maintain the system);

Question 42

Albatross are birds. Many of the 22 species of albatross are listed by the International Union for Conservation of Nature (IUCN) Red List. …

Accepted Answer

2(a) any two from: 2 M1 identifies threat status of organisms or species; M2 monitors, organisms / ecosystems; M3 raises awareness; M4 aims to influence policies or laws in favour of biodiversity; 2(b) any two from: 2 M1 increased, rainfall / flooding / sea level rise, washes away nests; M2 increased, storms / wind / extreme weather, blows away nests; M3 increased temperature / lack of rainfall, dries out or cracks mud; M4 loss of land due to sea level rise so less available land to build nests; M5 this increases competition for available land; 2(c) M1 phytoplankton; 2 M2 total of four levels and with arrows in correct direction; phytoplankton → small fish → large fish → albatross 2(d)(i) M1 don’t need to kill the albatross; 2 M2 (albatross are) listed in (IUCN) Red List / idea of being endangered or threatened; 2(d)(ii) M1 3.88 g per g circled; 2 M2 biomagnification / concentration (of toxins) increases up a food chain; 2(e) M1 tag or (radio) tracker fitted to bird; 2 M2 (location transmitted which is) received by GPS; 2(f)(i) tally used with 34 shown; 1 2(f)(ii) using large numbers of people / general public, to obtain data; 1 2(f)(iii) total four from: 4 max three benefits: M1 large area can be sampled; M2 do not need to go to where albatrosses are / Antarctica is difficult to get to; M3 does not disturb albatrosses / does not disturb environment; M4 quick to sample / quick to take images; M5 birds are not counted twice (in static image); max three limitations: M6 idea of big data / time consuming (to count or analyse all images); M7 idea of albatross huddled together so difficult to see or count individual birds; M8 can’t be used when cloudy; M9 expense (of satellite); M10 cannot identify different species; 2(g) M1  sum of (total); 3 M2 n number of individuals of each species (present in the sample); M3 N total number of all individuals in all species (present in sample);

Question 43

Fig. 3.1 shows part of a sand dune. The dune is a hill of sand made by the wind near the sea. Fig. 3.1 A scientist investigates four specie…

Accepted Answer

3(a) total max four from: 4 max three from building trap: M1 dig a hole and insert or bury a container; M2 container should have a small hole or drainage in base; M3 cover trap; M4 cover raised slightly at sides; max three from use trap: M5 leave trap for period of time; M6 identify and count insects M7 release insects; 3(b) correct label position for: 2 pioneer species; climax community; intermediate species; 3 correct = 2 1–2 correct = 1 3(c) to obtain a representative sample / to calculate a mean value; 1 3(d)(i) D; 1 3(d)(ii) numbers increase / greater distribution, closer to the sea; 1 3(d)(iii) 25; 1 3(d)(iv) 1650; 1

Question 44

Rhinoceros are at risk from climate change. (a) A scientist uses capture-mark-recapture to record the number of rhinoceros in an area. (i) …

Accepted Answer

2(a)(i) any one from: 1 M1 may stress or frighten the animals; M2 increased risk of predation; M3 reduces chance of breeding success; M4 time consuming; 2(a)(ii) n1 (total) number of individuals captured in first sample; 3 n2 number of individuals captured in second sample both marked and unmarked; m2 number of marked individuals recaptured in second sample; 2(b) any three from: 3 M1 (only) continent of Africa; M2 highest in south(east) of Africa / mostly southern tip of continent; M3 (highest in) region of Tropic of Capricorn (in Africa) / mostly south of Equator / mostly southern hemisphere; M4 relevant quoted data; e.g. 1001–2500 in South of Africa 2(c)(i) 1970–1975 circled; 1 2(c)(ii) any three from: 3 M1 national park created; M2 hunting or poaching ban; M3 patrols / surveillance; M4 international protection e.g. IUCN red list; M5 increased awareness / education (on conservation); M6 captive breeding programme; 2(d)(i) March / Mar; 1 2(d)(ii) 10; 1 2(d)(iii) any three from: 3 M1 high rainfall; M2 high temperatures bake soil; M3 ground cannot absorb water; M4 leads to flooding; M5 climate change leads to extreme weather; 2(d)(iv) provides place to avoid (flood)water / mounds provide high ground; 1 2(d)(v) any two from: 2 M1 predation; M2 hunting / poaching; M3 competition for named resource, e.g., food / water / shelter / space; M4 disease / pests;

Question 45

(a) Fig. 5.1 shows the ‘Firelight Toilet’ system. Content removed due to copyright restrictions. Fig. 5.1 The system heats and dries toilet…

Accepted Answer

5(a)(i) any three from: 3 treated toilet waste: M1 better sanitation / reduces risk of diseases / reduces risk of contamination of water sources; M2 named disease or illness e.g. diarrhoea / cholera / dysentery; clean water produced: M3 clean water can be used for named purpose; e.g., irrigation / household use closed system: M4 reduces risk of leakage into water sources; M5 reduces open defecation (prevents water contamination); M6 water (for flushing), is produced from toilet waste / is recycled; M7 less water is used; 5(a)(ii) any two from: 2 M1 provides source of electricity or energy; M2 no chemicals added to toilet (which could contaminate water sources); M3 no pit needs to be dug to store waste; M4 ash can be used as a fertiliser; 5(b) any two from: 2 M1 water demand in increasing; M2 water availability is decreasing; M3 rate of increase and decrease the same; M4 demand exceeds availability in or after 2040; 5(c)(i) M1 axes labels and units: volume of water / billion m3 and all years indicated / year; 3 M2 suitable linear scale whereby plotted data occupies at least half the grid; M3 5 correct plots; 5(c)(ii) any two from: 2 M1 data is for, USA / one country; M2 not all countries are HICs; M3 differing, amounts of industrialisation or needs between rural and urban areas; M4 no data after 2010; M5 unpredictable events (may change industry usage by 2030); 5(d) any three from: 3 M1 improved irrigation / named improvement e.g. trickle drip; M2 growing crops less dependent on high water supply / GM modified drought resistant crops; M3 recycling water; M4 rainwater catchment; M5 mulching / covering soil (to reduce evaporation); M6 wind breaks (to reduce evaporation); M7 limits on water volume (legally) allowed to be used / legislation; 5(e) ground water and permafrost 2nd and 3rd box ticked; 1 5(f) any four from: 4 M1 water source or intake uphill from village; M2 idea of small dam that raises water level locally; M3 idea of source protected from contamination e.g. limited agriculture / no housing; M4 settlement tank / sediments or solids fall to bottom of a tank; M5 pressure break tank; M6 pipes to village; M7 idea of water treatment; e.g. add iodine tablets / chlorination / storage tank / water stand posts / taps M8 not all water taken from source (to maintain the system);

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Questions174 pages

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Q17 · A conservationist investigates the population of beetles in five different locations in… 8291/21 Oct/Nov 2023

Q18 · Spraying aerosols into the stratosphere and growing crops with shiny leaves are two… 8291/22 Oct/Nov 2023

Q19 · Rice is the main food of three billion people and provides one fifth of the calories… 8291/22 Oct/Nov 2023

Q20 · The UK government promotes the use of electric cars 8291/22 Oct/Nov 2023

Q21 · A student investigates the concentration of nitrate ions in a lake 8291/23 Oct/Nov 2023

Q22 · A conservationist investigates the population of beetles in five different locations in… 8291/23 Oct/Nov 2023

Q23 · Water usage by sector in the USA and Nigeria 8291/21 May/June 2024

Q24 · In 2022, 80% of the timber used in the UK was imported 8291/21 May/June 2024

Q25 · Methane is an atmospheric pollutant 8291/21 May/June 2024

Q26 · Scientists use tree ring data to investigate tree growth in a local area 8291/22 May/June 2024

Q27 · The European bee‑eater bird 8291/22 May/June 2024

Q28 · The European bee‑eater bird 8291/23 May/June 2024

Q29 · ‘Climate TRACE’ is a global organisation that collects and shares data on greenhouse gas… 8291/21 Oct/Nov 2024

Q30 · Bats are flying nocturnal mammals 8291/22 Oct/Nov 2024

Q31 · Gold is a valuable metal 8291/22 Oct/Nov 2024

Q32 · ‘Climate TRACE’ is a global organisation that collects and shares data on greenhouse gas… 8291/23 Oct/Nov 2024

Q33 · A farmer investigates insect pests on soybean plants 8291/23 Oct/Nov 2024

Q34 · Water turbidity measures the cloudiness of water 8291/21 May/June 2025

Q35 · A questionnaire is used to obtain the opinions of people in different regions on the… 8291/22 May/June 2025

Q36 · A ghost swift moth 8291/22 May/June 2025

Q37 · An increase in wild fires is an impact of climate change 8291/22 May/June 2025

Q38 · A questionnaire is used to obtain the opinions of people in different regions on the… 8291/23 May/June 2025

Q39 · An increase in wild fires is an impact of climate change 8291/23 May/June 2025

Q40 · Rhinoceros are at risk from climate change 8291/21 Oct/Nov 2025

Q41 · The ‘Firelight Toilet’ system 8291/21 Oct/Nov 2025

Question 42 8291/22 Oct/Nov 2025

Q43 · Part of a sand dune 8291/22 Oct/Nov 2025

Q44 · Rhinoceros are at risk from climate change 8291/23 Oct/Nov 2025

Q45 · The ‘Firelight Toilet’ system 8291/23 Oct/Nov 2025