Impacts of human activity on ecosystems — Paper 2 · A Level Environmental Management (AS only) 8291

4 Fig. 4.1 shows changes in the world’s biodiversity according to the Living Planet Index from 1970 to 2003. The index compares biodiversity to the 1970 levels. index (1970 = 1.0) 1.1 1.0 0.9 biodiversity index 0.8 0.7 0.6 1970 1974 1978 1982 1986 1990 1994 1998 2002 year Key freshwater ecosystem (lakes and rivers) marine ecosystem terrestrial ecosystem Fig. 4.1 (a) With reference to Fig. 4.1, describe and explain the trends shown in the biodiversity index of freshwater, marine and terrestrial ecosystems. [10] (b) Conservation can involve a ‘species approach’, which protects species from extinction, or an ‘ecosystem approach’, which protects populations of species in their natural habitats. With reference to examples, compare the advantages of both approaches to conservation. [30] [Total: 40]

40 marks

Mark scheme: 4(a) trends: Overall the graph shows a decrease in biodiversity since 1970 in all ecosystems, from a biodiversity index of 1.0 in 1970. In freshwater ecosystems biodiversity initially increased between 1970 and 1983 with a rise in the biodiversity index from 1.0 to 1.1. This was followed by a significant decrease to a biodiversity index of approx. 0.71 in 2003. There was also an overall increase in biodiversity between 1970 and 1975 in marine ecosystems, followed by a decline to a biodiversity index of approx. 0.72 in 2003. Terrestrial ecosystems show a decreasing trend, ending with the lowest biodiversity index of approx. 0.69 in 2003. However, there are fluctuations and anomalies, for example, 1995 in marine ecosystems or 2000 in freshwater ecosystems. Reasons for decreases include, for example in terrestrial ecosystems, changing land use, habitat loss, pollution such as acid rain and the introduction of invasive species. In marine ecosystems reasons for decreases include marine pollution (e.g. oil spills), climate change, increase in shipping transportation and overexploitation. In freshwater ecosystems reasons for decreases include increases in organic pollutants, sewage disposal and agricultural run-off. Reasons for increases include, for example, pollution control of rivers, waste management and environmental protection. Please use level descriptors 1 10 Question Answer Marks 4(b) The question requirements are: • to consider how a ‘species approach’ can protect species • to consider how an ‘ecosystem approach’ can protect populations in their natural habitats • to compare the advantages of the two approaches • to use examples of conservation. Indicative content: A species approach protects species from extinction. Endangered species are identified, legally protected, and their critical habitat is preserved. Breeding can take place in a wildlife sanctuary or special reserve or in captivity, in a zoo and then reintroduced into suitable habitats. An ecosystem approach protects populations of species in their natural habitats. By preserving areas in the biomes through government action in ecological islands, nature reserves or national parks. Degraded ecosystems can be restored. Advantages of each approach should be considered and compared. A species approach can prevent extinction of a species. Iconic species can help to raise awareness and funds, which can be used generally for conservation. Through protecting the habitat for one species the habitat is also protected for other species. An ecosystem approach considers the need for an entire functioning ecosystem, which protects a range of species including species which may not have even been discovered. Protecting an ecosystem also gives other benefits, for example watershed protection or carbon sequestration depending on examples used. Please use level descriptors 2 30

This question in 8291/21 May/June 2017

1 (a) Fig. 1.1 shows a pyramid of biomass with three trophic levels. trophic level 3 trophic level 2 trophic level 1 Fig. 1.1 (i) What is meant by the terms biomass and trophic level ? biomass … … trophic level … … [2] (ii) State the names of the trophic levels shown in Fig. 1.1. trophic level 3 … trophic level 2 … trophic level 1 … [3] (iii) Describe the relationship between the trophic levels shown in the pyramid in Fig. 1.1 and explain its shape. … … … … … … … … [4] (b) Fig. 1.2 shows the change in percentage coral cover on Caribbean coral reefs from 1973 to 2010. 60 50 40 percentage coral cover 30 20 10 0 1970 1980 1990 2000 2010 year Fig. 1.2 (i) Using the data from Fig. 1.2, describe the change in percentage coral cover from 1973 to 2010. … … … … … … [3] (ii) Suggest how human activities can contribute to the loss of coral cover. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) biomass: (dry) mass / grams of living organisms (per unit area / ecosystem); trophic level: feeding level in a food chain / food web; 2 1(a)(ii) trophic level 3: secondary consumers / carnivores; trophic level 2: primary consumers / herbivores; trophic level 1: producers / plants / organisms containing chlorophyll / chloroplasts / autotrophic organisms; 3 1(a)(iii) organisms at trophic level 1 (autotrophs / producers) produce food by photosynthesis (using sunlight energy); trophic levels 2 and 3 contain organisms (consumers / heterotrophs) that obtain energy through feeding on other organisms; organisms at a higher trophic level feed on the organisms at the level / levels below / organisms at TL 3 feed on organisms at TL 2 / organisms at TL 2 are eaten by organisms at TL 3 / organisms at TL 1 are eaten by organisms at TL 2; biomass decreases at each trophic level as less energy is transferred through the trophic levels from TL 1 to higher levels; but energy decreases through the trophic levels as less energy is available as a result of energy losses from the food chain at each trophic level; e.g., in excretion / movement / not all of the organism is consumed; energy is lost to the environment in respiration; 4 Question Answer Marks 1(b)(i) overall decrease 1973 to 2010 / trend shows a fall in coral cover over time; use of data to support, e.g. approx. 58% highest value to approx. 10% so approx. 48% loss; fluctuations / anomalies in overall decrease noted; ref. to initial increase in coral cover for short period; 3 1(b)(ii) Award one mark for each suggested human activity which can contribute to coral loss. (Max. of four for a list of activities.) Award marks for development and exemplification of how the activity contributes to coral loss. (Max. of four marks for any one activity developed and exemplified.) For example: pollution of the marine environment; example of organic or inorganic pollution, e.g. fertiliser from agriculture; oil; heavy metals; plastics; run-off / siltation; increase in non-coral algae / reduction in coral algae; damaging fishing activities, e.g. blast fishing / dynamite fishing; overfishing; ref. to relevant effect on potential food web / food chain affecting coral cover; coastal development; construction; placing material over coral reefs; extraction, e.g. dredging / digging navigation channels; for shipping / boat access; blasting / coral mining for building materials; destroys coral reef; tourism effects; boating / diving; untreated sewage from hotels etc.; 8 Question Answer Marks 1(b)(ii) coral harvesting; e.g. use in jewellery; e.g. use in fish tanks etc.; burning of fossil fuels; increasing carbon dioxide levels / rising of sea levels / climate change; ocean warming; acidification; coral bleaching;

This question in 8291/22 May/June 2017

2 (a) Fig. 2.1 shows part of a water cycle in a tropical rainforest. rainfall evapotranspiration transpiration evaporation interception stem flow direct throughfall leaf drip infiltration throughflow run-off Fig. 2.1 (i) State what is meant by the following terms: evaporation … … interception … … run-off. … … [3] (ii) With reference to Fig. 2.1, describe how a balance between inputs and outputs of water can be maintained in a tropical rainforest. … … … … … … … … … … … … [6] (b) Fig. 2.2 shows a section of a slope containing undisturbed forest on the left and the same slope after deforestation on the right. undisturbed forest after deforestation soil + roots trees water tableKey evaporation and transpiration table water rainfall run-off infiltration saturated rock river soil / sediment Fig. 2.2 (i) Using Fig. 2.2, describe the effect of deforestation on the local water cycle. … … … … … … … … … … … … [6] (ii) Suggest methods that can be used to reduce the impact of deforestation on the local environment. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) evaporation: formation of water vapour / gas from liquid water; interception: capture of rainfall as it falls / rainfall is prevented from reaching the ground directly; run-off: water moving over soil / land surface; 3 Question Answer Marks 2(a)(ii) Award one mark for a list of correct inputs and outputs. Award development of either inputs or outputs to a max. of three marks each. Award a max. of four marks if there is no balance, e.g. only input. Award one mark for a summative statement of identified input(s) equal to identified output(s). inputs: rainfall, precipitation, throughflow AND outputs: throughflow, run-off, evapotranspiration; (Accept evaporation or transpiration.) description of inputs in rainforest: some rain as it falls is collected / stored by the leaves of the tropical rainforest canopy; (interception) water runs down plant stems / tree trunks to the soil surface; (stem flow) water from leaves drops / reaches the ground; (leaf drip) and water moves into the soil store; (infiltration) water is absorbed by the roots / taken up by vegetation / moves through the plant via the transpiration stream, some is used by the plant in photosynthesis / primary productivity and stored in plant biomass; water moves into the area by groundwater flow from groundwater stores outside of the area; (Credit use as an output to other areas.) description of outputs in rainforest: water in the soil can move downwards, percolation to groundwater stores and groundwater flow; (run-off) transport to rivers / river discharge; water loss from vegetation / soil surfaces (evaporation); roots of plants take up water from the ground, from leaves into the atmosphere (transpiration); water vapour condenses into clouds / to the atmospheric water store; 6 Question Answer Marks 2(b)(i) less water in vegetation store; with less vegetation there is a reduction in interception; increased impact of rainfall on the soil surface; soil compaction; reduced infiltration; less water in the soil water store; less percolation to groundwater; lowering of the water table; increase in surface run-off; increase in soil erosion; increased siltation / sediment accumulation in river channel; increased risk of flooding during period of rain; reduction in evapotranspiration; credit ref. to local microclimate, e.g. less cloud / less humidity / less rainfall / less atmospheric water; possible desertification; Credit references to the deforested slope compared to undisturbed forest in Fig. 2.2. 6 Question Answer Marks 2(b)(ii) Award one mark for each method. Allow up to two further marks per method for development and exemplification. forest conservation; e.g. protected areas / national park; to reduce habitat loss / prevent loss of biodiversity; afforestation; re-populating the area with more trees to increase roots in soil; to reduce exposed soil area; resource managed areas; e.g. selective logging; to maintain tree cover; natural succession; eliminating grazing animals; ecosystem restoration; sustainable land use / changing agricultural practices; agroforestry / combining agricultural and forestry technologies; combining trees and shrubs with crops and / or livestock; intercropping / two or more plant species; increase ground cover; using mulch; contour ploughing; terracing; planting buffer strips adjacent to river; 5 Section B

This question in 8291/22 May/June 2017

1 (a) Fig. 1.1 shows a pyramid of biomass with three trophic levels. trophic level 3 trophic level 2 trophic level 1 Fig. 1.1 (i) What is meant by the terms biomass and trophic level ? biomass … … trophic level … … [2] (ii) State the names of the trophic levels shown in Fig. 1.1. trophic level 3 … trophic level 2 … trophic level 1 … [3] (iii) Describe the relationship between the trophic levels shown in the pyramid in Fig. 1.1 and explain its shape. … … … … … … … … [4] (b) Fig. 1.2 shows the change in percentage coral cover on Caribbean coral reefs from 1973 to 2010. 60 50 40 percentage coral cover 30 20 10 0 1970 1980 1990 2000 2010 year Fig. 1.2 (i) Using the data from Fig. 1.2, describe the change in percentage coral cover from 1973 to 2010. … … … … … … [3] (ii) Suggest how human activities can contribute to the loss of coral cover. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) biomass: (dry) mass / grams of living organisms (per unit area / ecosystem); trophic level: feeding level in a food chain / food web; 2 1(a)(ii) trophic level 3: secondary consumers / carnivores; trophic level 2: primary consumers / herbivores; trophic level 1: producers / plants / organisms containing chlorophyll / chloroplasts / autotrophic organisms; 3 1(a)(iii) organisms at trophic level 1 (autotrophs / producers) produce food by photosynthesis (using sunlight energy); trophic levels 2 and 3 contain organisms (consumers / heterotrophs) that obtain energy through feeding on other organisms; organisms at a higher trophic level feed on the organisms at the level / levels below / organisms at TL 3 feed on organisms at TL 2 / organisms at TL 2 are eaten by organisms at TL 3 / organisms at TL 1 are eaten by organisms at TL 2; biomass decreases at each trophic level as less energy is transferred through the trophic levels from TL 1 to higher levels; but energy decreases through the trophic levels as less energy is available as a result of energy losses from the food chain at each trophic level; e.g., in excretion / movement / not all of the organism is consumed; energy is lost to the environment in respiration; 4 Question Answer Marks 1(b)(i) overall decrease 1973 to 2010 / trend shows a fall in coral cover over time; use of data to support, e.g. approx. 58% highest value to approx. 10% so approx. 48% loss; fluctuations / anomalies in overall decrease noted; ref. to initial increase in coral cover for short period; 3 1(b)(ii) Award one mark for each suggested human activity which can contribute to coral loss. (Max. of four for a list of activities.) Award marks for development and exemplification of how the activity contributes to coral loss. (Max. of four marks for any one activity developed and exemplified.) For example: pollution of the marine environment; example of organic or inorganic pollution, e.g. fertiliser from agriculture; oil; heavy metals; plastics; run-off / siltation; increase in non-coral algae / reduction in coral algae; damaging fishing activities, e.g. blast fishing / dynamite fishing; overfishing; ref. to relevant effect on potential food web / food chain affecting coral cover; coastal development; construction; placing material over coral reefs; extraction, e.g. dredging / digging navigation channels; for shipping / boat access; blasting / coral mining for building materials; destroys coral reef; tourism effects; boating / diving; untreated sewage from hotels etc.; 8 Question Answer Marks 1(b)(ii) coral harvesting; e.g. use in jewellery; e.g. use in fish tanks etc.; burning of fossil fuels; increasing carbon dioxide levels / rising of sea levels / climate change; ocean warming; acidification; coral bleaching;

This question in 8291/23 May/June 2017

2 (a) Fig. 2.1 shows part of a water cycle in a tropical rainforest. rainfall evapotranspiration transpiration evaporation interception stem flow direct throughfall leaf drip infiltration throughflow run-off Fig. 2.1 (i) State what is meant by the following terms: evaporation … … interception … … run-off. … … [3] (ii) With reference to Fig. 2.1, describe how a balance between inputs and outputs of water can be maintained in a tropical rainforest. … … … … … … … … … … … … [6] (b) Fig. 2.2 shows a section of a slope containing undisturbed forest on the left and the same slope after deforestation on the right. undisturbed forest after deforestation soil + roots trees water tableKey evaporation and transpiration table water rainfall run-off infiltration saturated rock river soil / sediment Fig. 2.2 (i) Using Fig. 2.2, describe the effect of deforestation on the local water cycle. … … … … … … … … … … … … [6] (ii) Suggest methods that can be used to reduce the impact of deforestation on the local environment. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) evaporation: formation of water vapour / gas from liquid water; interception: capture of rainfall as it falls / rainfall is prevented from reaching the ground directly; run-off: water moving over soil / land surface; 3 Question Answer Marks 2(a)(ii) Award one mark for a list of correct inputs and outputs. Award development of either inputs or outputs to a max. of three marks each. Award a max. of four marks if there is no balance, e.g. only input. Award one mark for a summative statement of identified input(s) equal to identified output(s). inputs: rainfall, precipitation, throughflow AND outputs: throughflow, run-off, evapotranspiration; (Accept evaporation or transpiration.) description of inputs in rainforest: some rain as it falls is collected / stored by the leaves of the tropical rainforest canopy; (interception) water runs down plant stems / tree trunks to the soil surface; (stem flow) water from leaves drops / reaches the ground; (leaf drip) and water moves into the soil store; (infiltration) water is absorbed by the roots / taken up by vegetation / moves through the plant via the transpiration stream, some is used by the plant in photosynthesis / primary productivity and stored in plant biomass; water moves into the area by groundwater flow from groundwater stores outside of the area; (Credit use as an output to other areas.) description of outputs in rainforest: water in the soil can move downwards, percolation to groundwater stores and groundwater flow; (run-off) transport to rivers / river discharge; water loss from vegetation / soil surfaces (evaporation); roots of plants take up water from the ground, from leaves into the atmosphere (transpiration); water vapour condenses into clouds / to the atmospheric water store; 6 Question Answer Marks 2(b)(i) less water in vegetation store; with less vegetation there is a reduction in interception; increased impact of rainfall on the soil surface; soil compaction; reduced infiltration; less water in the soil water store; less percolation to groundwater; lowering of the water table; increase in surface run-off; increase in soil erosion; increased siltation / sediment accumulation in river channel; increased risk of flooding during period of rain; reduction in evapotranspiration; credit ref. to local microclimate, e.g. less cloud / less humidity / less rainfall / less atmospheric water; possible desertification; Credit references to the deforested slope compared to undisturbed forest in Fig. 2.2. 6 Question Answer Marks 2(b)(ii) Award one mark for each method. Allow up to two further marks per method for development and exemplification. forest conservation; e.g. protected areas / national park; to reduce habitat loss / prevent loss of biodiversity; afforestation; re-populating the area with more trees to increase roots in soil; to reduce exposed soil area; resource managed areas; e.g. selective logging; to maintain tree cover; natural succession; eliminating grazing animals; ecosystem restoration; sustainable land use / changing agricultural practices; agroforestry / combining agricultural and forestry technologies; combining trees and shrubs with crops and / or livestock; intercropping / two or more plant species; increase ground cover; using mulch; contour ploughing; terracing; planting buffer strips adjacent to river; 5 Section B

This question in 8291/23 May/June 2017

1 (a) Fig. 1.1 gives information on some effects of increasing urban development on a local water cycle. increasing urban development % of land covered by 0 25 75 100 impervious surfaces (an impervious surface does not allow water to infiltrate) precipitation 100 100 100 100 / arbitrary units evaporation 40 38 35 30 (includes evapotranspiration) / arbitrary units infiltration 50 42 35 15 / arbitrary units run-off 10 20 30 55 /arbitrary units Fig. 1.1 (i) With reference to Fig. 1.1, describe the trend between increasing urban development and both evaporation and infiltration in this local water cycle. evaporation … … … … infiltration … … … … [4] (ii) Using the data in Fig. 1.1, calculate the percentage increase in run-off from 0% land covered by impervious surfaces to 100% land covered by impervious surfaces. Show your working. … % [2] (iii) Explain why an increase in the percentage of land covered by impervious surfaces increases run-off. … … … … [2] (iv) Briefly explain two effects of run-off from urban areas on a river environment. … … … … … … … … [4] (b) Fig. 1.2 shows a vegetation zoning system designed to reduce the impact of human activity on a river environment. run-offrun-offfrofromm agriculturalagricultural lalanndd run-orun-o ffff fromfrom ururbabann lalandnd river zone 3 zone 2 zone 1 zone 1 zone 2 zone 3 grass managed natural natural managed grass forest forest forest forest benefits wildlife habitat protection flood reduction nutrient uptake by vegetation run-off reduction river bank stability Fig. 1.2 Describe and explain how the vegetation zoning system shown in Fig. 1.2 reduces the negative impact of human activity on the river environment. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) Trend: with increasing urban development / more buildings and less vegetation or soil cover, there is a decreasing evaporation; with (increasing urban development) there is decreasing infiltration; use of data/information from Fig.1.1to support trend: there is an overall decrease from, 40 to 30 / 10 arbitrary units of evaporation and 50 to15 arbitrary / 35 units of infiltration; further manipulation of data e.g. a non-linear rate of decrease is described / e.g. increasing impervious surfaces by 25% decreases evaporation by 2 units (5%) but increasing impervious surfaces by 100% decreases evaporation by 10 units (25%), 5 × more; 4 Do not accept any references to differences in rainfall in questions 1(a)(i)–(iv). Accept alternative descriptions using data and information. 1(a)(ii) 55 – 10 / 10 = 45 / 10 = 4.5; 4.5 × 100 = 450% 2 Award 2 marks for a correct answer without working. 450% = 2 marks ecf for incorrect difference from (i). 1(a)(iii) impermeable / non-porous surfaces; prevent water from being absorbed / prevent infiltration into the ground; more water will flow overland as run-off; there is less resistance to run-off (due to less vegetation / soil) increasing the rate of flow of water overland; reference to structure of the impervious surfaces e.g. gullies which collect and channel the flow of water across the surface of the land to drains; 2 Question Answer Marks Guidance 1(a)(iv) run-off contains pollutants which contaminate the river environment; e.g. oil from vehicles collects on the water surface; reducing light penetration; decreasing photosynthesis by aquatic plants; nutrients from garden fertilisers, increases the concentration of nutrients in the river water / eutrophication; lowers biodiversity; organic matter in sewage increases biochemical oxygen demand; depletion of oxygen in water; detergents / chemicals; alter the pH of the water; run-off carries sediment / debris; increasing turbidity; run-off increases river discharge; increasing the chance of river flooding; damaging / eroding waterside vegetation / river banks; 4 Award 1 mark for a general point on effect of pollution. Or For each of 2 effects 2 × 2. (1 mark for an explanation of 1 effect and 1 mark for further exemplification.) Pollution must refer to be river pollution. Do not accept pollutants which are not carried in run-off. Do not accept fertiliser alone – must be linked to an urban area. Do not accept increased run-off alone as in previous question. Question Answer Marks Guidance 1(b) zone 1 / natural forest is linked to the stabilising of river bank by: tree roots holding soil particles; reducing the risk of riverbank erosion; zones 1 and 2 / natural and managed forest is linked to reducing the likelihood of river flooding through: forest soil absorbing water; reducing river discharge; trapping sediment / soil from agricultural land; reducing sedimentation; zone 2 / managed forest has fast-growing plants which increase nutrient uptake; zones 1–3 / natural forest, managed forest, grass increase nutrient uptake: vegetation absorbs excess nutrients; reducing the input of nutrients into the river / reducing the risk of eutrophication; zones 1–3 / natural forest, managed forest, grass slows the rate of run-off : by providing ground cover; increasing infiltration; improving drainage; zones 1–3 / natural forest, managed forest, grass increases biodiversity by: providing ecological benefits for wildlife; nesting / breeding sites; stratification / variety of habitats / niche; other benefits not listed in Fig. 1.2: e.g. filters groundwater flow from non-point source pollution; acts as a buffer strip; 8 Max 5 if zoning system discussed as a whole and no analysis of zones.

This question in 8291/21 Oct/Nov 2017

2 (a) Fig. 2.1 shows part of a food web for a coral reef ecosystem. reef shark angelfish pufferfish butterflyfish crown-of-thorns sea sponge fan worm starfish zooplankton green turtle microscopic photosynthetic algae in coral seagrass filamentous phytoplankton coral algae Fig. 2.1 (i) From Fig. 2.1, identify one organism at: the first trophic level … the second trophic level … the third trophic level. … [2] (ii) Suggest the role of the microscopic photosynthetic algae living within the coral, as shown in Fig. 2.1. … … … … [2] (iii) With reference to Fig. 2.1, describe and explain one effect of an increase in the number of crown-of-thorns starfish on the amount of coral. … … … … [2] (iv) With reference to Fig. 2.1, explain one effect of overfishing in the seas around the coral reefs. … … … … [2] (b) Fig. 2.2 shows the threats to and the impact of human activity on coral reefs. The map is divided into two regions, region A South East Asia and region B Australia and Papua New Guinea. Pacific region Ocean A S.E.S.E. AsiaAsia region B PapuaPapua NewNew Indian GuineaGuinea Ocean Australia Key threats fishing pollution coral harvesting tourism impact on the coral percentage in region percentage in region reefs A B already destroyed 37 2 critical 28 3 threatened 27 15 at low threat 8 80 Fig. 2.2 (i) With reference to Fig. 2.2, compare the threats to and the impact of human activity on the coral reefs in region A and region B. … … … … … … … … … … … … [6] (ii) Describe and explain methods that can be used to preserve and conserve coral reefs. … … … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) e.g.: 1st trophic level: sea grass / filamentous algae / phytoplankton / photosynthetic algae; 2nd trophic level: green turtle / zooplankton / butterfly fish / coral / reef shark; 3rd trophic level: sea sponge / fan worm / coral / reef shark; 2 2 / 3 trophic levels correct for 2 marks 1correct for 1 mark. Allow algae. 2(a)(ii) absorb sunlight energy; produce (organic) food (photosynthesis); nutrients for coral organisms; symbiotic relationship; 2 No mark for photosynthesis alone; 2(a)(iii) reduced size of coral (colony) / decreased amount of coral; increased predation of coral; more feeding by crown-of thorns starfish; 2 2(a)(iv) reduced fish stock / declining fish populations; reduces food source for higher level consumers / tertiary consumers; reduces the number of primary consumers (or named); less consumption of filamentous algae / increasing non-coral algae; increased competition for light / nutrients; decrease in the algae associated with coral; less competition for the crown-of-thorns starfish for coral; increasing population of predatory crown-of-thorns starfish; destructive fishing methods damaging the coral; 2 Question Answer Marks Guidance 2(b)(i) Threats: A (South East Asia) has greater overall threat with a higher number of threats; compared to B (Australia and Papua New Guinea) with fewer threats; In A (South East Asia) mainly due to threats from fishing; and more threats in every category of threat (fishing, pollution, coral harvesting, tourism) – use of data from map; compared to in B in Papua New Guinea with the largest threat from pollution from land, followed by tourism in Australia and (dynamite) fishing in Papua New Guinea; no coral harvesting in B; Impact: A greater overall impact (reference to data); largest % of coral reefs already destroyed and large % of critical and threatened and lowest % of low impact (8%); B has less impact with the largest % in the low risk category (80%); lower % in all other categories of already destroyed, critical and threatened (20%); 6 Answer must be comparative. Award a max of 4 for either threats or impacts. Question Answer Marks Guidance 2(b)(ii) restricting coastal developments which cause sedimentation on the reefs; sediment damages the coral colonies; increased turbidity reduces light for the coral algae; reducing land based sources of marine pollution; reducing nutrient input into to the sea by reducing fertilisers from agricultural runoff; reducing sewage from domestic sources; excess nutrients encourage the growth of non-coral algae which outcompete the coral algae; reducing marine based pollution by; impose fishing regulations; reducing the exploitation of the coral reef organisms; ban the use of dynamite / cyanide in fishing ; control human marine activities; restrict areas of boating / snorkelling to minimise damage to coral; educate the public; establish protected areas to preserve species and protect habitats; national park / marine park / conservation area; zones for different uses e.g. recreation, shipping ; monitoring the coral: 6

This question in 8291/21 Oct/Nov 2017

3 Fig. 3.1 is a diagram representing energy flow and nutrient recycling in an ecosystem. energy out of the ecosystem tertiary consumers secondary consumers energy from detritivores the Sun and decomposers primary consumers producers Key nutrient biomass store energy flow nutrient recycling Fig. 3.1 (a) With reference to Fig. 3.1, describe the flow of energy and the recycling of nutrients in an ecosystem. [10] (b) Describe the impact of deforestation on forest ecosystems. Using examples, assess the strategies used to reduce the pressures on forest ecosystems. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Energy enters the ecosystem as sunlight energy, is transferred by photosynthesis to chemical energy in primary productivity and transferred through the trophic levels from producers to consumers when one organism feeds on another, in food chains. Energy is also transferred to the detritivores and decomposers. At each trophic level energy is lost from the ecosystem as heat in respiration. Nutrients are absorbed from the soil by plants, assimilated and passed along the food chains when one organism feeds on another. Dead plants and animals are broken down by detritivores, decomposed by decomposers and the nutrients released into the soil. Both energy and nutrients transfer through food chains. Energy flows through the ecosystem while, nutrients are recycled. Please use level descriptors 1 10 Question Answer Marks Guidance 3(b) The question requirements are: • to describe the impacts of deforestation on terrestrial ecosystems • to describe strategies to reduce the human impact upon ecosystems • to assess the strategies • to use examples Indicative content: Deforestation impacts upon the forest ecosystem through loss of habitat and loss of food supply nesting and breeding sites for the community of organisms. Declining populations result in a loss of biodiversity, with species becoming vulnerable, threatened and at risk of extinction. Deforestation also impacts the forest environment by affecting climate and the hydrological cycle, for example through reduced evapotranspiration. Soil is impacted through increased surface run-off and the nutrient cycles are affected by increased leaching of soil, soil erosion and soil degradation. Strategies to reduce the impact of deforestation include the sustainable use of forest resources for example through selective logging in timber managed areas or agroforestry, by maintaining the forest but using the land for growing a suitable crop. Establishing protected forest reserves, preventing the illegal logging of specific species and afforestation of fragmented forest areas can be effective strategies. Education by emphasising the benefits of maintaining forest cover and associated wildlife and encouraging ecotourism for the economic value of the forest are alternative strategies. Please use level descriptors 2 30

This question in 8291/21 Oct/Nov 2017

1 (a) Fig. 1.1 shows the relationship between precipitation and temperature for some major biomes. 4500 4000 3500 A 3000 average annual precipitation 2500 / mm 2000 temperatetemperate 1500 deciduousdeciduous forestforest 1000 savannahsavannah grassland 500 C B 0 –20 –15 –10 –5 0 5 10 15 20 25 30 average annual temperature / °C Fig. 1.1 (i) State what is meant by the term biome. … … [1] (ii) Use Fig. 1.1 to name the biomes labelled A, B and C. A … B … C … [2] (iii) Use Fig. 1.1 to state the range of temperature and precipitation within the temperate deciduous forest biome. range of temperature … range of precipitation … [2] (iv) State one factor, other than temperature and precipitation, which determines the distribution of the major biomes. … … [1] (v) Suggest why the boundaries between some of the biomes shown in Fig. 1.1 overlap. … … … … [2] (b) Fig. 1.2 shows the stores and the flows of nutrients within a tropical rainforest ecosystem. In this diagram the sizes of the circles and the width of the arrows are proportional to the quantity of nutrients. Key B B biomass P L litter S soil Le leaching W weathering R run-off L P precipitation S flow of nutrients Le store of nutrients R W Fig. 1.2 (i) With reference to Fig. 1.2, describe how the nutrient balance of a tropical rainforest ecosystem is maintained. … … … … … … … … [4] (ii) Fig. 1.3 shows three different ways human activity impacts on tropical rainforest ecosystems. photograph X photograph Y photograph Z Fig. 1.3 Describe the impacts of human activity on tropical rainforest ecosystems. Refer to Fig. 1.2 and Fig. 1.3 in your answer. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 1(a)(i) regional, biotic community characterised by a dominant form of vegetation type (and distinct climate); 1 Allow large scale ecosystem. 1(a)(ii) A Tropical rainforest; B Desert; C Tundra; 2 1 mark for any 1 correct. 2 marks for any 2 / 3 correct. 1(a)(iii) temperature range: between 1.5 degrees centigrade to 21 degrees centigrade; precipitation range: between 520 mm to 2350 mm; 2 Accept a range from just above 0–2 and 20–21. Accept a correct calculated difference. Accept a range from 500–600 and 2300–2400. Accept a correct calculated difference. 1(a)(iv) latitude / altitude / soil; 1 1(a)(v) conditions do not usually change abruptly; there is a gradual change in climate .e.g. becoming drier / wetter; transition in terms of vegetation from one biome to another; 2 Accept a well described example e.g. desert to savannah grassland / shrub-land to forest. 1(b)(i) input of nutrients from precipitation is greater than output by runoff; nutrient flow from the biomass to the litter store together with the nutrient input from precipitation, is balanced with the flow of nutrients to the soil store; balanced with the uptake of nutrients by the vegetation from the soil store; vegetation / biomass have proportionally the largest nutrient store compared to soil / litter; (rapid) decomposition of dead plant material and incorporation into soil; (rapid) uptake of nutrients and incorporation into biomass; or (rapid) recycling of nutrients; inputs from weathering equal losses by leaching; 4 Question Answer Marks Guidance 1(b)(ii) human activity impacting on the forest: photograph X : part of the forest is cleared by burning / slash and burn; for subsistence agriculture; photograph Y : large tracts of forest are clear-cut by logging for; urban development / infrastructure / mining / commercial agriculture (e.g. oil palm plantation); photograph Z : the forest is largely deforested; replaced with grass for cattle-ranching; impacts on the community of organisms in the ecosystem: fragmentation of habitats; loss of habitats; reduction in food supply; loss of nesting / breeding sites; loss of biodiversity; a wide range of species threatened with risk of extinction; impacts on the environment on the hydrological cycle / climate: reduced evapotranspiration; reduced precipitation; carbon sink reduction; increased surface run-off; impact on soil: removal of the biomass store; removes input to litter store; reduces soil nutrient store; increased leaching of nutrients; soil erosion / soil degradation; soil compaction by trampling; 8 Max.6 marks if there is no reference to Fig.1.3. or Fig.1.2.

This question in 8291/22 Oct/Nov 2017

2 (a) Fig. 2.1 shows a diagram of a local water cycle. precipitation evaporation from vegetationinfiltration evaporation A B water table riverriver groundwater flow groundwater flow (not to scale) Key A proposed urban development B agricultural activity Fig. 2.1 (i) With reference to Fig. 2.1, state one input and one output of the local water cycle. input … output … [1] (ii) Use Fig. 2.1 to explain why the level of the water table may rise and fall. … … … … … … [3] (iii) Explain how proposed urban development in the area labelled A in Fig. 2.1 could increase the chance of flooding. … … … … … … … … [4] (iv) Explain how agricultural activity in the area labelled B in Fig. 2.1 could cause the river to become polluted. … … … … … … … … [4] (b) Fig. 2.2 shows effects of a single event of organic pollution on a river. river concentration distance Key input of organic pollution organic pollution river flow organic matter mineral ions (e.g. nitrates and phosphates) dissolved oxygen Fig. 2.2 With reference to Fig. 2.2, describe and explain the changes in the quality of river water with increasing distance from the input of organic pollution. … … … … … … … … … … … … … … … … [8] [Total: 20]

20 marks

Mark scheme: 2(a)(i) input: precipitation / river / groundwater flow; output: evaporation / evapotranspiration / river / groundwater flow; 1 Both correct for one mark. Accept evapotranspiration for evaporation from vegetation. 2(a)(ii) water table can rise – an explanation linking: increased rainfall; increased infiltration; pores in underground, porous store fill with water / saturated; water table can fall – an explanation linking: increased temperature; increased uptake of water from soil by vegetation; increased evaporation (from vegetation) / evapotranspiration; reduced precipitation; less infiltration; decrease in saturated zone; increase in extraction of water for human use; 3 Credit reverse arguments only once i.e. increased / deceased precipitation / rainfall. 2(a)(iii) reduced soil / vegetation cover; increase in impermeable surfaces; less infiltration; increased surface run-off; increase in poor quality runoff-from land surface; water collected from drains; increased discharge to streams / river; 4 Award up to 4 marks for single points or award 2 × 2 marks for 2 developed points. Question Answer Marks Guidance 2(a)(iv) less permanent vegetation cover; soil surface exposed for long periods between crops; increased loss of nutrients from soil; increased leaching; increased nutrient in surface run-off; increased nutrient in groundwater flow due to infiltration and percolation through permeable layers into the groundwater; increased use of fertilisers on land; irrigation water; enhanced nutrient load; eutrophication; 4 Accept alternative agricultural effects e.g. grazing animals. Award up to 4 marks for single points or award 2 × 2 marks for 2 developed points. Question Answer Marks Guidance 2(b) description of water quality: a decrease in water quality immediately following the discharge of organic pollution; as shown by the initial increase in density of organic pollution / increase in organic matter; decrease in dissolved oxygen; followed by a gradual improvement in water quality downstream; decreasing organic pollution with distance downstream / gradual decease in organic matter; gradual increase in oxygen levels; explanation: sewage effluent / discharge; contains suspended solids / organic matter; increases turbidity; oxygen levels decrease due to decomposition; by decomposer organisms / e.g.; use oxygen in respiration; increased BOD; decreasing organic matter levels are due to the breakdown of organic matter; dispersion / dilution; increased oxygenation of water; due to aeration of water; decreasing microbial activity; the gradual increase in concentration of mineral ions can be linked to the release of minerals from the decomposition of organic material; 8 Award notionally 4 marks for description and 4 for explanation.

This question in 8291/22 Oct/Nov 2017

1 (a) Fig. 1.1 shows the flows and stores of nutrients in a tropical rainforest ecosystem. biomass leaf fall uptake by plants precipitation weathering litter soil 13% of 14% of nutrients nutrients run-off decomposition leaching Key store of nutrients flow of nutrients input / output Fig. 1.1 (i) Calculate the percentage of nutrients stored in biomass in the tropical rainforest ecosystem shown in Fig. 1.1. … % [1] (ii) State what is meant by the term biomass. … … [1] (iii) With reference to Fig. 1.1, describe the interactions between the stores of nutrients within a tropical rainforest ecosystem. … … … … … … [3] (iv) Explain how precipitation influences the stores and flows of nutrients in a tropical rainforest ecosystem. … … … … … … … … [4] (v) Explain why more nutrients are stored in biomass than in the litter and soil in a tropical rainforest. … … … … … … [3] (b) Fig. 1.2 shows human activities that lead to deforestation of a tropical rainforest. 5% other* 10% logging 20% large-scale 45% small-scale commercial agriculture agriculture (oil palm) 20% pasture (cattle ranching) *other includes urbanisation, mining, construction of roads and dams Fig. 1.2 (i) Describe the ways in which the human activities shown in Fig. 1.2 affect the nutrient cycle in the tropical rainforest shown in Fig. 1.1. … … … … … … … … … … [5] (ii) Suggest ways in which the impact of human activities on tropical rainforest ecosystems can be reduced. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) 73%; 1 1(a)(ii) (mass of) living / biotic / organic (components of the ecosystem) (per unit area / ecosystem); mass of living organisms, in a given area, measured in grams per square metre; 1 1(a)(iii) nutrients are recycled in the ecosystem; (inorganic compounds / nutrients) from the soil are absorbed by plant roots into the plant; assimilation (into organic compounds) / (secondary) productivity; growth; stored as wood / new biomass; dead leaves / dead organisms / leaf fall are incorporated into leaf litter; leaf litter is broken down / decays; due to the action of detritivores / microbial action; humus formation; nutrients are released into the soil store as (inorganic compounds / minerals) soil is enriched; 3 Question Answer Marks 1(a)(iv) precipitation outputs: run-off, removes nutrients (dissolved in precipitation); leaching removes nutrients from the soil store by; percolation to groundwater; precipitation inputs: nutrients, dissolved in rainfall; e.g. nitrite; throughfall / interception / leaf drip / stem flow; infiltration of rainwater into soil store; nutrients dissolved in solution; allows the uptake of nutrients by plants; by diffusion / active transport; used in plant growth and stored in biomass; (chemical weathering) of bedrock releases nutrients into the soil store; 4 1(a)(v) rapid rate of decomposition of (organic material); due to increased rate of microbial activity; high temperature and high humidity / rainfall provide optimum conditions for this (rapid decomposition); rapid incorporation of nutrients into humus; rapid recycling of nutrients / nutrients spend a relatively short time period in litter and soil; longevity / nutrients are incorporated by organisms over a long period of time in growth; 3 Question Answer Marks 1(b)(i) removal of the biomass; increased surface run-off; increased nutrient loss from soil store; increased leaching of soil; soil erosion / soil degradation; the destruction of the vegetation results in loss of habitat; loss of food supply; loss of nesting and breeding sites for the community of organisms; declining populations; biodiversity loss / species are vulnerable / threatened / at risk of extinction; effect on climate / hydrological cycle, e.g.; a change in rates of evaporation / evapotranspiration; a change in precipitation rate; risk of flooding; subsistence agriculture has the highest percentage use (45%) but has less effect on the nutrient cycles; the ecosystem can be restored through natural succession; only small fragmented areas are used; nutrients are replenished through nutrient recycling; the effect of logging (10%) will be dependent on the type of logging / area of land involved; cattle ranching (20%) / plantation (20%) have greater effect due to removal of biomass from large areas; overgrazing; soil compaction by trampling; pasture land has less effect on nutrient cycles, as the ground is covered with vegetation and soil cover is maintained (compared to plantation where the soil is part exposed during the growing season) / and manure is added; although the lowest percentage of deforestation (5%) is from the ‘others’ category, e.g. mining, dams, these have a greater effect due to complete removal of biomass and soil pollution; 5 Question Answer Marks 1(b)(ii) sustainable agriculture in conservation areas; e.g. agroforestry which combines using the land for growing a suitable crop within the forest thus maintaining the forest; use crop rotation; subsistence agriculture using small fragmented areas with sufficient time for natural succession; sustainable use of forest resources; selective logging in timber managed areas; removing some trees from forest while maintaining the overall forest as opposed to clear cutting large areas; preventing the illegal logging of specific species; afforestation; of fragmented forest areas; re-growing the forest; protected areas / protected forest reserves; national parks; restricting impact of human activity by, e.g.; raising awareness through education of the economic value of and benefits of maintaining forest cover and its associated wildlife; ecotourism; 3

This question in 8291/21 May/June 2018

3 Fig. 3.1 shows the number of major oil spills from tankers in the world’s oceans in four successive decades. 260 240 220 200 180 160 number of 140 major oil spills 120 100 80 60 40 20 0 1970 − 79 1980 − 89 1990 − 99 2000 − 09 year Fig. 3.1 (a) With reference to Fig. 3.1, describe the change in the number of major oil spills and suggest reasons for this change. [10] (b) Briefly describe the main sources of marine pollutants other than oil spills. Using examples, explain to what extent the pollution of the marine environment can be managed by individual countries. [30] [Total: 40]

40 marks

Mark scheme: 3(a) A decreasing trend is shown in the number of oil spills from tankers in each decade (245, 93, 77 and 35 oil spills). The largest decrease occurred between the 1970s and 1980s with a decrease of 152 spills subsequently followed by a slowing in the rate of decrease. The number of oil spills was six times greater between 1970–79 to, compared to 2000– 09. Suggested reasons for the changes may include reference to changes in shipping regulations; changes in the size and the design of ships for oil transportation or to an overall reduction in the transport of oil, linked to decreasing demand and the use of alternative fuel and energy resources. Please use level descriptors 1 10 3(b) The question requirements are: • to describe the main sources of pollution other than oil spills • to use examples of the management of marine pollution • to explain to what extent marine pollution can be managed by individual countries Indicative content: Sources of marine pollution include, for example, sewage; agricultural run-off; industrial wastewater; natural sources; drainage of coastal ecosystems; deforestation; dredging and urban development. Reference can be made to the management of marine pollution by individual countries through examples of laws or policies; the management of waste; changes in agricultural practices; coastal ecosystem restoration; shipping regulations; the establishment of protected areas; pollution controls; as well as education, awareness and research. For example pollution of the Great Barrier Reef is effectively managed through the establishment of a marine park and zoning plan. An assessment may consider that as sources of pollution occur some distance from their effect and cross international borders, for example air pollution or due to maritime transportation which together, with the dispersal of marine pollutants make management difficult. Environmental management resulting from international management plans may be more effective, for example, UNEP’s Regional Seas Program. Please use level descriptors 2 30

This question in 8291/21 May/June 2018

1 (a) Table 1.1 shows the approximate residence time for some major water stores. Residence time is the time water spends in a particular water store. Table 1.1 water store approximate residence time glaciers 10 to 10 000 years deep groundwater 10 000 years shallow groundwater 100 to 200 years lakes 10 to 100 years living organisms 1 week oceans 4000 years rivers 2 weeks to 6 months soil moisture 2 weeks to 1 year (i) State the water store with the lowest approximate residence time in Table 1.1. … [1] (ii) With reference to Table 1.1, suggest why the residence times given in Table 1.1 are approximate. … … … … [2] (b) Fig. 1.1 is a newspaper extract about an incident of river pollution in Brazil. November 2015 River and sea threatened by industrial sludge Dams holding 50 million cubic metres of iron-mine waste collapsed and discharged a flood of thick, red, toxic sludge. The sludge covered a small town and made its way into the River Doce. A 650 km stretch of the river was affected. The sludge greatly increased the concentration of suspended particles in the water and drastically reduced the oxygen levels. People living in the area are now dependent on supplies of bottled water. Two weeks later the water in the estuary (where the river joins the sea) turned brown. The pollution then spread out along the coast, affecting a nature reserve containing nesting sites of the endangered leatherback turtle. Fig. 1.1 (i) State the source of the river pollution referred to in Fig. 1.1. … … [1] (ii) With reference to Fig. 1.1, describe how the river became polluted. … … [1] (iii) Suggest the effects of the pollution on the quality of the river water. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (iv) Fig. 1.2 shows the distribution of the pollution where the River Doce flows into the sea. River Doce pollution sea Fig. 1.2 Explain the distribution of the pollution in the sea shown in Fig. 1.2. … … … … [2] (v) Describe the possible effects of industrial pollution on coastal and marine environments. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (c) Briefly describe strategies that can be used to manage river pollution. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 1(a)(i) living organisms; 1 1(a)(ii) there is a wide variation in the residence time for water stores of each type; water stores have different volumes / locations / size; rates of input / output vary; different factors can change over time; e.g. rivers will vary in size, each river will have a different value, and so (a range of values); 2 1(b)(i) mining waste / industrial waste / toxic metals; 1 1(b)(ii) dam burst, waste sludge released, flowed into the river; 1 1(b)(iii) increased turbidity / an increased concentration of suspended particles; reduced light penetration / less light for plants in water; reduced photosynthesis / death of plants; reduced oxygen levels; less respiration; death of animals / organisms in water; reduced biodiversity; increased concentration of metals in water; water contamination; reduced quality of water as drinking water for human consumption / agricultural use / water supply for livestock; 4 1(b)(iv) where the river flows into estuary, a concentrated area is visible, extending over a wide area with decreasing intensity; due the sea currents / tide; extending both out to sea and along the shoreline; disperses / dilution / mixing of the pollution with a large volume of sea water; 2 Question Answer Marks 1(b)(v) death of aquatic organisms; reduced food supply for both aquatic and land based organisms; effect on food chains / web; effect on population size of species; reduced biodiversity; bioaccumulation; degradation of the marine environment; detrimental to the aesthetics of the coastal environment; negative economic effects / fishing industry / human food supply / effect on tourism; Fig.1.1: describes an effect linked to the nature reserve; reduces breeding / nesting sites of the endangered leatherback turtle; 4 1(c) management of leakage, seepage, run-off from industrial sites; eliminating or reducing pollution at source; reducing waste discharge; recycling of waste water to reduce input into river; enforced legislation controlling the discharge of industrial waste; monitoring of rivers by suitable organisations to identify changes in water quality; risk assessment; clean-up operations; management of any form of river pollution not just industrial: reducing agricultural run-off through appropriate management; management of domestic waste by water treatment and waste treatment. 5

This question in 8291/22 May/June 2018

2 (a) Fig. 2.1 shows part of a natural forest ecosystem before deforestation. Fig. 2.2 shows agriculture on the same land after deforestation. precipitation precipitation nutrients in forest tree biomass canopy interception nutrients are removed nutrients in when the crop crops is harvested heavy run-off nutrients in light run-off leaf litter and soil shallow roots deep roots heavy leaching light leaching Before deforestation Agriculture after deforestation Fig. 2.1 Fig. 2.2 (i) State one abiotic and one biotic component in a natural forest ecosystem. abiotic … biotic … [2] (ii) With reference to Fig. 2.1, describe how the biotic and abiotic components of a natural forest ecosystem interact. … … … … … … … … [4] (iii) With reference to Fig. 2.1 and Fig. 2.2, explain the environmental effects of deforestation and then using the land for agriculture. … … … … … … … … [4] (b) Fig. 2.3 shows agroforestry. This is one way of changing the agricultural system to be more sustainable. In agroforestry, crops are grown as part of a forest ecosystem. coffee crops Fig. 2.3 Describe and explain how agroforestry can help restore and conserve forest ecosystems. Refer to Fig. 2.1, Fig. 2.2 and Fig. 2.3 in your answer. … … … … … … … … … … [5] (c) Another strategy for conserving a forest ecosystem sustainably is to encourage ecotourism. Outline the benefits of ecotourism in the sustainable development of ecosystems. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 2(a)(i) abiotic; e.g. soil / water / light / nutrient; biotic: e.g. trees / plants / vegetation / microorganisms / fungi; 2 2(a)(ii) Light and plants: light is absorbed by leaves; primary productivity / photosynthesis; energy is transferred in food chains; minerals and plants: plant absorb minerals / nutrients from soil; used for growth / secondary productivity; stored as biomass; temperature and decomposers: leaf litter provides food for decomposers / detritivores; process of decomposition returns nutrients to soil; higher temperatures increase the rate of microbial action and thus rate of decomposition; precipitation and trees: weathering of parent rock releases nutrients; nutrients are dissolved in solution; tree roots absorb nutrients from the soil; water and vegetation: vegetation cover prevents excessive run-off; water from precipitation infiltrates the soil; plants absorb water from the soil in roots 4 Question Answer Marks 2(a)(iii) loss of nutrients from the ecosystem; as nutrients are removed from the ecosystem when a crop is harvested; nutrients are not recycled; there are no deep roots to utilise nutrients from the weathering of bedrock and increased leaching; loss of soil fertility; the soil surface is more exposed; there is often no permanent vegetation cover / the vegetation cover is reduced; increased runoff results in soil erosion / soil degradation; removal of vegetation / biomass; habitat destruction; 4 2(b) maintains / restores some natural vegetation; provides habitats for organisms; food chains / webs / niche; conserves / increases biodiversity; preserves natural predators of pests; reduces need for artificial pesticides; organic matter is introduced through as leaf fall; (organically) fertilises the soil; reduces need for (artificial) fertilisers; maintains a hydrological / soil balance; permanent vegetation cover; reduces soil exposure / increase soil stability / reduces wind erosion; other economic benefits; co-operation between land use for agriculture and logging; 5 Question Answer Marks 2(c) supports nature conservation; offers environmental benefits; protects ecological balance; reduces pressure on natural resources; economic benefits; natural unspoilt areas have a value; provides opportunities for income generating activities; e.g. game reserve entrance fees / safari tours; helps create job opportunities for locals e.g. employment as rangers / guides; diversifies the economy; improves the income levels for locals; money raised can be used for the maintenance and management of the areas; for conservation / environmental management projects; socio-cultural benefits; local traditions are preserved; local community can be involved in providing services e.g.; educate the public on conservation; 5

This question in 8291/22 May/June 2018

1 (a) Table 1.1 shows the approximate residence time for some major water stores. Residence time is the time water spends in a particular water store. Table 1.1 water store approximate residence time glaciers 10 to 10 000 years deep groundwater 10 000 years shallow groundwater 100 to 200 years lakes 10 to 100 years living organisms 1 week oceans 4000 years rivers 2 weeks to 6 months soil moisture 2 weeks to 1 year (i) State the water store with the lowest approximate residence time in Table 1.1. … [1] (ii) With reference to Table 1.1, suggest why the residence times given in Table 1.1 are approximate. … … … … [2] (b) Fig. 1.1 is a newspaper extract about an incident of river pollution in Brazil. November 2015 River and sea threatened by industrial sludge Dams holding 50 million cubic metres of iron-mine waste collapsed and discharged a flood of thick, red, toxic sludge. The sludge covered a small town and made its way into the River Doce. A 650 km stretch of the river was affected. The sludge greatly increased the concentration of suspended particles in the water and drastically reduced the oxygen levels. People living in the area are now dependent on supplies of bottled water. Two weeks later the water in the estuary (where the river joins the sea) turned brown. The pollution then spread out along the coast, affecting a nature reserve containing nesting sites of the endangered leatherback turtle. Fig. 1.1 (i) State the source of the river pollution referred to in Fig. 1.1. … … [1] (ii) With reference to Fig. 1.1, describe how the river became polluted. … … [1] (iii) Suggest the effects of the pollution on the quality of the river water. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (iv) Fig. 1.2 shows the distribution of the pollution where the River Doce flows into the sea. River Doce pollution sea Fig. 1.2 Explain the distribution of the pollution in the sea shown in Fig. 1.2. … … … … [2] (v) Describe the possible effects of industrial pollution on coastal and marine environments. Refer to Fig. 1.1 in your answer. … … … … … … … … [4] (c) Briefly describe strategies that can be used to manage river pollution. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 1(a)(i) living organisms; 1 1(a)(ii) there is a wide variation in the residence time for water stores of each type; water stores have different volumes / locations / size; rates of input / output vary; different factors can change over time; e.g. rivers will vary in size, each river will have a different value, and so (a range of values); 2 1(b)(i) mining waste / industrial waste / toxic metals; 1 1(b)(ii) dam burst, waste sludge released, flowed into the river; 1 1(b)(iii) increased turbidity / an increased concentration of suspended particles; reduced light penetration / less light for plants in water; reduced photosynthesis / death of plants; reduced oxygen levels; less respiration; death of animals / organisms in water; reduced biodiversity; increased concentration of metals in water; water contamination; reduced quality of water as drinking water for human consumption / agricultural use / water supply for livestock; 4 1(b)(iv) where the river flows into estuary, a concentrated area is visible, extending over a wide area with decreasing intensity; due the sea currents / tide; extending both out to sea and along the shoreline; disperses / dilution / mixing of the pollution with a large volume of sea water; 2 Question Answer Marks 1(b)(v) death of aquatic organisms; reduced food supply for both aquatic and land based organisms; effect on food chains / web; effect on population size of species; reduced biodiversity; bioaccumulation; degradation of the marine environment; detrimental to the aesthetics of the coastal environment; negative economic effects / fishing industry / human food supply / effect on tourism; Fig.1.1: describes an effect linked to the nature reserve; reduces breeding / nesting sites of the endangered leatherback turtle; 4 1(c) management of leakage, seepage, run-off from industrial sites; eliminating or reducing pollution at source; reducing waste discharge; recycling of waste water to reduce input into river; enforced legislation controlling the discharge of industrial waste; monitoring of rivers by suitable organisations to identify changes in water quality; risk assessment; clean-up operations; management of any form of river pollution not just industrial: reducing agricultural run-off through appropriate management; management of domestic waste by water treatment and waste treatment. 5

This question in 8291/23 May/June 2018

1 (a) Fig. 1.1 is a diagram of a mangrove ecosystem, which is an example of a coastal water ecosystem. muddy roots of mangrove trees soil coastal inland water high tide changing water low tide level white black red sea mangrove tree mangrove trees mangrove trees grass Fig. 1.1 (i) With reference to Fig. 1.1, state two components of a mangrove ecosystem. … … [2] (ii) With reference to Fig. 1.1, suggest two effects of the changing water level between high tide and low tide on the mangrove ecosystem. … … … … [2] (b) Table 1.1 shows the estimated global mangrove area between 1980 and 2010. Table 1.1 year 1980 1990 2000 2010 estimated global mangrove 18.79 16.93 15.74 15.23 area / million ha (i) With reference to Table 1.1, describe the changes in estimated global mangrove area between 1980 and 2010. … … … … [2] (ii) Using the data in Table 1.1, calculate the difference in estimated global mangrove area between 1980 and 2010 as a percentage. Show your working. … % [2] (iii) Explain reasons why coastal water ecosystems, such as mangrove ecosystems, are at risk. … … … … … … … … [4] (c) Fig. 1.2 shows restoration of a mangrove ecosystem. Fig. 1.2 (i) With reference to Fig. 1.2, briefly explain what is meant by ecosystem restoration. … … … … [2] (ii) Briefly explain two benefits of conserving coastal water ecosystems, such as mangrove ecosystems. … … … … … … … … [4] (iii) Suggest one benefit of community involvement in conservation of ecosystems. … … … … [2] [Total: 20]

20 marks

Mark scheme: 1(a)(i) vegetation / trees; water; soil; max 2 1(a)(ii) transition / zonation of the vegetation (with different types of mangrove adapted to the varying conditions); roots of the mangrove trees (have alternating periods of exposure to air and submergence in water); water is saline / brackish ( mangrove trees are salt tolerant / adapted to increased levels of salinity); soil is waterlogged / oxygen deficient (mangrove trees have aerial roots / breathing roots, so oxygen can diffuse from the air into these roots); mangrove tree roots (buttress, prop roots, stilt) are adapted to provide support in muddy / soft soil; max 2 1(b)(i) decrease in mangrove coverage; use or manipulation of data: e.g. the largest decrease occurs between 1980 and 1990 / 1.86 million hectares; 2 1(b)(ii) (18.79 – 15.23) = 3.56; 3.56 / 18.79 × 100 = 18.95%; 2 Question Answer Marks 1(b)(iii) (coastal water ecosystems are at risk from) human activity / natural events which destroy / disrupt / damage the ecosystem; reasons: coastal water ecosystems are used for aquaculture; rivers flowing into the ecosystem are dammed; water is drained artificially; (water cleared so) the land can be used agriculture / coastal development; timber is cut for fuelwood / charcoal industries; climate change / increase in tropical storms / increase in sea level / flooding; water pollution due to e.g. sewage/nutrients from agriculture; explanation: biodiversity is reduced; ecosystem balance / ecosystem stability is disrupted; water flow / water levels are changed; removing coastal vegetation increases coastal erosion; max 4 1(c)(i) through human intervention / conservation activities; a degraded ecosystem is improved / a destroyed ecosystem is replaced; e.g. trees are planted; organisms bred in captivity / native species are re-introduced; invasive species are removed; max 2 Question Answer Marks 1(c)(ii) any two benefits explained: filters run-off from land; reducing pollution of coastal water; provides habitats; maintains species / biodiversity; provides niche; feeding sites / breeding grounds / nesting sites for birds / nursery for fish or other organisms; sediment is trapped; stabilising roots / soil; provides storm / flood / shore protection; against tsunamis / tidal surges; max 4 1(c)(iii) less destruction / less degradation of the ecosystem; through increased education / environmental awareness; or economic benefits; through an increase in fishing stock / preventing overfishing; or incentive to further conserve; through positive feedback / as benefits to the community become apparent; max 2

This question in 8291/21 Oct/Nov 2018

3 Fig. 3.1 shows global human population and estimated biodiversity from the year 1000 until 2015. 13 12 100 11 10 9 75 global 8 biodiversity population / billion people 7 / arbitrary units 6 50 5 4 3 25 2 1 0 0 1000 1250 1500 1750 2000 year Key biodiversity population Fig. 3.1 (a) Describe the relationship between the global human population and biodiversity shown in Fig. 3.1. Suggest reasons for this relationship. [10] (b) Assess to what extent humans can reduce the loss of biodiversity and provide resources for an increasing human population. Refer to examples in your answer. [30] [Total: 40]

40 marks

Mark scheme: 3(a) There is a negative correlation between human population size and biodiversity. With an increase in population, there is a decrease in biodiversity. A slow increase in population relates to a slow decrease in biodiversity. An exponential increase in population relates to greater decrease in biodiversity. For example between the year 1000 and the year 1500 the population increased by approximately 0.2 billion, while biodiversity decreased by 2 units. By the time the population had reached 1 billion biodiversity decreased more than 10 units. In 2015 with a global human population of 7.4 billion biodiversity has decreased by 25 units. Human population growth has resulted in a decrease in species diversity due to the impact of human activity on ecosystems. As more land is used for urban development, roads and industry and more forest is cleared for agriculture, natural ecosystems are destroyed and habitats lost for example in tropical rainforest. An increasing human population has generated more marine, terrestrial, and freshwater pollution damaging and degrading ecosystems for example through eutrophication, reducing biodiversity. Man has disrupted the stability of ecosystems for example through the exploitation of species resulting in species extinctions. please use level descriptors 1 10 Question Answer Marks 3(b) The question requirements are: • to consider sustainable ways of providing human resources • to assess to what extent these methods can provide the resources for an increasing population • to assess to what extent these methods can limit loss of biodiversity • to use examples. Indicative content: Sustainability is the use and management of resources that allows full natural replacement of the resources exploited and full recovery of the ecosystems affected by their extraction and use. Sustainable methods which provide resources and yet limit loss of biodiversity include sustainable agriculture practices, agriculture in conservation areas, resource managed areas, sustainable fishing practices and agroforestry. An assessment will consider whether degradation of the environment and the consumption of resources by the human population will continue to lead to further loss of biodiversity or whether sufficient resources for a growing population can be produced by sustainable methods halting the loss of biodiversity. Reducing population growth rates and reducing ecological footprint may also be considered. please use level descriptors 2 30

This question in 8291/21 Oct/Nov 2018

1 (a) Fig. 1.1 gives information about the sources of nitrogen compounds and phosphorus compounds (nutrients) entering a lake. source percentage of total percentage of total nitrogen phosphorus compounds compounds sewage 31.5 58.7 urban run-off 5.5 10.0 manured land 9.9 21.5 other crop land 0.7 3.1 rural run-off forest land 0.5 0.3 pasture 0.7 2.9 rural ground water 42.7 2.3 precipitation onto water 8.5 1.2 precipitation urban rural onto water sources sources run-off run-off from from forest urban areas run-off from pasture and manured land excess discharge nutrients from sewage treatment run-off from works algal bloom crop land infiltration lake ground water flow Fig. 1.1 (i) State the source that contributes the highest percentage of nitrogen compounds to the lake, as shown in the table in Fig. 1.1. … [1] (ii) Suggest where the nitrogen and phosphorus compounds (nutrients) in the urban run-off shown in Fig. 1.1 originated. … … … … … … [3] (iii) Use Fig. 1.1 to calculate the difference between the total percentage of nitrogen compounds and the total percentage of phosphorus compounds entering the lake from rural run-off. Show your working. … % [2] (iv) Explain why there is a high percentage of nitrogen compounds entering the lake through rural ground water, as shown in Fig. 1.1. … … … … … … … … [4] (b) Describe and explain the effects of excess nutrients entering a lake. … … … … … … … … … … … … [6] (c) Suggest ways in which the pollution of water stores can be reduced. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 1(a)(i) rural groundwater; 1 1(a)(ii) compounds: (decomposing) organic matter / nitrogen oxides / NOx / phosphates/ nitrates / ammonium compounds; sources: (decomposing) organic matter: waste material from streets; waste disposal sites; nitrogen oxides / NOx : air pollutants; from cars / industry; dissolved in precipitation / rainfall; phosphates: e.g. detergents; domestic sources / street cleaning / car washing; nitrates: from garden fertilisers; ammonium compounds: septic tanks / untreated sewage; storm drainage; max 3 1(a)(iii) (Total % of nitrogen compounds 11.8, total % of phosphorous compounds 27.8) / 27.8 – 11.8; 16; 2 Question Answer Marks 1(a)(iv) non-point source of pollution, from a large area; rainfall/precipitation falls on the land ; water is infiltrated into soil; nutrients from e.g. (inorganic) fertiliser / (organic) manure; are dissolved in soil water; some nutrients not absorbed by the forest / cropland / pasture; leaching; percolation / seep to water table / groundwater; groundwater flow to lake; max 4 1(b) eutrophication; reference to algal bloom in Fig.1.1: increased / excessive growth of algae or plants; (algae bloom) blocks out light for underwater plants below; (underwater) plants cannot photosynthesise; resulting in death and decay of algae or plants; increase in population of microorganisms or decomposers or bacteria; oxygen used in respiration; oxygen depletion of water; reduced biodiversity; death of aquatic organisms; max 6 Question Answer Marks 1(c) reduce pollutants in run-off into water store e.g. reduce pollution from sewage / reduce agricultural run-off; improve waste disposal systems; water treatment / tertiary treatment; re-use of grey water / recycling of water; control of agricultural run-off through e.g. timing of fertiliser application or quantity of fertiliser; buffer strips; legislation to reduce industrial sources; fines for polluters: monitoring of nutrient levels in run-off; measuring of water quality variables in water stores; e.g. oxygen concentration, BOD, biotic index; max 4

This question in 8291/22 Oct/Nov 2018

2 (a) Fig. 2.1 shows the distribution of the tundra biome and Fig. 2.2 shows the number of polar bears living in this biome. Arctic Circle, 66.5 °N Tropic of Cancer, 23.5 °N Equator Tropic of Capricorn, 23.5 °S Key tundra biome Fig. 2.1 RUSSIA Area 2 Area 3 ? Area 1 Area 4 Arctic Ocean Area 5 Area 18 Area 12 ? Pacific ALASKA Area 17 Ocean Area 8 Area 14 Key Area 16 Area 7 GREENLANDnumber of polar bears <200 Area 13 Area 9 Atlantic 200–500 CANADA Ocean 500–1000 Area 10 1000–1500 Area trend 15 1500–2000 declining Area 11 2000–2500 Area 6 stable increasing 2500–3000 0 500 1000 insufficient data ? unknown km Fig. 2.2 (i) With reference to Fig. 2.1, describe the distribution of the tundra biome. … … … … [2] (ii) Outline factors that influence the distribution of the tundra biome. … … … … … … … … [4] (iii) With reference to Fig. 2.2, describe the evidence which suggests that the polar bear is at risk of extinction. … … … … … … … … [4] (b) Fig. 2.3 shows part of a food web in the Arctic. polar bear Arctic birds Arctic fox Arctic char fish ringed seal bearded seal Arctic cod fish amphipods shrimps capelin fish mussels zooplankton phytoplankton Fig. 2.3 Describe the effects of a decrease in the number of polar bears on the food web shown in Fig. 2.3. … … … … … … … … [4] (c) Explain the importance of international protocols in the management of the tundra biome. … … … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) high latitude; northern hemisphere; within Arctic Circle; surrounding the Arctic Ocean; max 2 2(a)(ii) climate; low average temperatures (–20 to 15); low average rainfall (less than 70 mm); soil; permafrost / permanently frozen soil layer; bare rocky areas / limited soil; vegetation; limiting factors for growth / productivity; vegetation is restricted to grasses, mosses, lichens, dwarf shrubs / low growing plants; treeless plains; latitude; effect on day length / insolation; ocean currents; max 4 2(a)(iii) populations are very low in some areas; less than 200 in Area 12 and Area 8 (Lancaster Sound / Kane Basin); populations are declining in 6 / 50% / examples of areas); a population range of less than 2000 in areas where the populations are declining; even in areas where the population is stable the range is only 1000–3000; there are only a few, areas where the population is currently increasing; population change and population numbers are unknown for large areas; max 4 Question Answer Marks 2(b) increase in population of polar bear prey; e.g. bearded seal; increased availability of food for other predators; e.g. ringed seal; increase in population of other predators; reduced competition; e.g. Arctic fox ; max 4 2(c) agreements / treaties are required in order to manage the environment; different nations must share a collective responsibility for the biosphere including the tundra biome; other countries can have an effect on the tundra not just those in the immediate region; problems originate in the industrialised nations far away from where the effects are felt; e.g. air pollution – greenhouse gases; resulting in global warming / rising temperatures; resulting in earlier spring melting / shrinking of sea ice; habitat loss for polar bear; e.g. marine pollution – due to shipping; oil pollution; ocean currents spread maritime pollution; impact on food web; max 6

This question in 8291/22 Oct/Nov 2018

(a) With reference to Fig. 4.1, compare and contrast the trends in changes to forest reserves globally. Suggest reasons for the trends. [10] (b) Assess the effectiveness of methods used in the conservation of a named ecosystem. [30] [Total: 40]

40 marks

Mark scheme: 4(a) Overall there is a greater decrease in forest reserves. Europe has the largest forest area in 2010 and also the largest increase, with a gain of 20 000 thousand hectares between 1990 and 2010. Although in 1990, Asia has the second lowest area of forest of all the regions with only 580 000 thousand hectares; Asia has increased forest cover between 2000 and 2010 by 10 000 thousand hectares. Decreases in forest area have occurred in S. America and Africa. These regions had the second and third highest area of forest cover of 940 000 thousand hectares and 750 000 thousand hectares in 1990. The largest decrease occurred in S. America with a loss of 80 000 thousand hectares in 20 years. Africa lost 60 000 thousand hectares with the largest decrease occurring between 1990 and 2000. There was increasing forest cover in North America cover between 1990 and 2000 but since then forest cover has remained constant at 670 000 thousand hectares. Exploitation of forests, the unsustainable harvesting of forest wood resources or use of forests for fuel wood contributes to the decrease in forest area. Rapid population growth with forests cleared to provide land for agricultural use, commercial cattle farming, plantations and urbanisation as well as building of infrastructure, dams, mining and climate change can also account for losses. Reasons for increases may include the conservation of the forest resources, forest restoration and afforestation. The more sustainable use of forest resources, alternative uses of forests for example in ecotourism, the establishment of protected areas and international agreements have also contributed to increases in forest cover. please use level descriptors 1 10 Question Answer Marks 4(b) The question requirements are: • to consider the conservation of a named ecosystem • to detail the strategies • to assess the effectiveness of the strategies. Indicative content: Content will be dependent upon the chosen example, e.g. a coral reef ecosystem or a forest ecosystem. Assessment should consider the extent to which the strategies have been effective in conserving the ecosystem or whether strategies have been ineffectual due to other factors which can impact upon the ecosystem. please use level descriptors 2 30

This question in 8291/22 Oct/Nov 2018

1 (a) Fig. 1.1 shows maps of Bangladesh and the surrounding area. Most of Bangladesh is a low‑lying area where floods often occur. Key CHINA international boundary NEPAL BHUTAN disputed boundary INDIA hills / mountains BANGLADESH INDIA MYANMAR THAILAND N Key Brahmaputra low-lying land Dinajpur hills / mountains Rangpur INDIA water international boundary city Jamalpur capital city Sylhet major river Mymensingh Rajshahi river Pabna Brahmanbaria Dhaka INDIA Narayanganj BANGLADESH Comilla Jessore Khulna INDIA Barisal Chittagong Mongla Bay of Bengal Cox’s Bazar 0 60 Indian Ocean km Fig. 1.1 (i) With reference to Fig. 1.1, suggest how the following human activities could cause flooding in Bangladesh: increased deforestation in Nepal … … … … increased dam building in India … … … … increased population in Bangladesh. … … … … [6] (ii) With reference to Fig. 1.1, suggest the impacts on Bangladesh of rising sea levels due to global warming. … … … … … … … … [4] (b) Fig. 1.2 is an internet article about world population growth and water supply. The 2009 World Water Development report stated that in 2000, 508 million people inhabited water‑scarce regions. The report predicted that the percentage of the world population affected by water scarcity could increase from 8% in 2000 to 47% in 2030. Water scarcity is directly linked to poverty. World population is expanding by 80 million people per year, increasing the demand for fresh water by about 64 billion m3 a year. Water withdrawals tripled over the last 50 years as a result of population growth. This rapid growth also caused the potential global availability of fresh water to decline. Fig. 1.2 (i) Using Fig. 1.2, describe the relationship between human population growth and water scarcity. … … … … [2] (ii) The human population is predicted to be 8.5 billion (8 500 000 000) in 2030. Calculate how many people could be affected by water scarcity according to Fig. 1.2. … billion [2] (iii) State what is meant by the term water demand. … … [1] (iv) Outline five ways population growth increases the demand for water. … … … … … … … … … … [5] [Total: 20]

20 marks

Mark scheme: 1(a)(i) Deforestation in Nepal: reduced evapotranspiration; increased run-off; faster soil erosion; increased silting; increased volume of water in rivers; Dams in India: reduced / intermittent flow; increases silting in Bangladesh; which reduces river depth; Increased Population: increasing urbanisation / construction; removal of trees; reduction in absorbent surfaces; increases run-off; more wells dug; lowers water table; leading to land subsidence; max 6 1(a)(ii) 70% of land is < 1 m above sea level / low-lying; Bangladesh is a flood plain; coastal defences inundated from both sides; coastal cities / named cities could flood / flooding occurs; damaging property / housing / infrastructure; increased salinization of soil leads to agricultural land being abandoned; salinization of water supply; less likely to have maintained levees; increased snow melt / increased rainfall contributes to flooding; population movement; loss of biodiversity; max 4 Question Answer Marks 1(b)(i) as population grows; the percentage of people in water scarcity increases; as population grows; the amount of water withdrawals triples; as population grows; global water availability declines; max 2 1(b)(ii) 8.5 × (47 / 100); 3.995 (Billion) / 3 995 000 000; 2 1(b)(iii) water demand is total needed from sources for domestic / industrial / agricultural use / for population to survive; 1 1(b)(iv) water needed for basic / domestic needs; example / e.g. hydration / hygiene / cooking / sewage systems; industrial use; for manufacture of goods / construction / energy generation; agricultural use; for growing food / animals; water used for non-basic needs; example / dishwashers, washing machines / washing cars / watering gardens; max 5

This question in 8291/21 May/June 2019

2 (a) Fig. 2.1 is a map of a region of the North West Pacific and a graph showing total input of nitrogen compounds into the sea for the areas marked on the map. Nitrogen compounds can be used as an indicator of the amount of pollution in water. RUSSIA CHINA Peter the Great Bay N. KOREA Toyama Bay S. KOREA Jinhae Bay JAPAN Northwest Kyushu sea area 0 1000 km 20 000 Key 18 000 input from waste water 16 000 input from rivers 14 000 12 000 total input of nitrogen compounds 10 000 (tonnes per year) 8 000 6 000 4 000 2 000 0 Northwest Toyama Bay, Jinhae Bay, Peter the Kyushu Japan South Korea Great Bay, sea area, Russia Japan Fig. 2.1 (i) Using Fig. 2.1, state which area receives the highest total input of nitrogen compounds from waste water. … … [1] (ii) Using Fig. 2.1, calculate the total input of nitrogen compounds from rivers per year into the four areas. … tonnes of nitrogen per year [2] (iii) Name the process in which pollution of lakes by compounds containing nitrogen and phosphorus leads to algal blooms. … [1] (iv) Explain how the process named in 2(a)(iii) leads to the loss of biodiversity. … … … … … … … … … … … … [6] (v) Suggest two human activities that lead to the pollution of water stores. 1. … … 2. … … [2] (b) Fig. 2.2 shows part of a food web for the North West Pacific region shown in Fig. 2.1. shark tuna dolphin sardines small fish crabs lobster zooplankton shrimp phytoplankton Fig. 2.2 (i) State two primary consumers shown in Fig. 2.2. … … [2] (ii) Tuna are becoming endangered in this region. Suggest two possible effects of this on the food web shown in Fig. 2.2. … … … … [2] (iii) Marine ecosystems are under threat from a range of human activities. Suggest strategies to manage these threats and to conserve these important habitats. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) Northwest Kyushu sea area 1 2(a)(ii) 26 200; 5200 + 10 000 + 6000 + 5000 or 5000 + 10 000 + 6000 + 5000 or 5000 + 10 000 + 6000 + 4900 or 5200 + 10 000 +6000 + 4900; 2 2(a)(iii) Eutrophication; 1 2(a)(iv) increased nitrate acts as fertiliser; plant growth increases rapidly; algae are plants and grow rapidly; excess growth leads to competition for resources; example e.g. sunlight; for photosynthesis; plants / algae die; decomposition occurs; microbes consume oxygen; for respiration; oxygen levels in water depleted; (invertebrates / vertebrates) die / move away; max 6 2(a)(v) waste from cattle farms; leaks from sewage; dumping / littering; industrial leaks; overuse of chemical fertilisers; overuse of manure; long term release of sewage from leaks; run-off; max 2 Question Answer Marks 2(b)(i) zooplankton; shrimp; 2 2(b)(ii) less food for shark; increased predation of sardines / small fish; reduced feeding on zooplankton; increased population of zooplankton; more food for shrimp / small fish; max 2 2(b)(iii) monitoring; international cooperation; legislation; fines; education; fisheries management; marine conservation zone; cleaning up pollution events; max 4

This question in 8291/21 May/June 2019

3 Fig. 3.1 is a flow diagram showing the effect of human pressure on an ecosystem and the possible management response. ecosystem damaged/disrupted Human pressure on Altered structure the ecosystem and use ecosystem restored ecosystem changed Management response Fig. 3.1 (a) With reference to Fig. 3.1, describe the effects of human activity on a named terrestrial ecosystem. [10] (b) ‘It is important to balance the needs of an increasing population with the need to protect the resources of the biosphere’. Using examples of countries with contrasting levels of economic development, assess the problems of achieving this balance. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Human activity could include pollution (named pollutant), physical habitat changes such as deforestation, dams and agriculture, urban sprawl, infrastructure building, poaching and hunting. These can lead to lower biodiversity, change in succession, eutrophication, flooding and loss of habitat. Human activity could also be the various management strategies to protect the terrestrial ecosystems Please use level descriptors 1 10 3(b) The question requirements are: • To explain the demands made by increasing population • To explain the importance of protecting the resources of the biosphere • To assess the different problems faced by countries with different levels of economic development in meeting both demands Increasing population leads to increased demands for living space (development and infrastructure) and pressure on the resources of the biosphere (loss of habitat, pollution, agriculture demands). Protection of the biosphere is important to maintain the balance in the biomes and to prevent irreversible change and loss of biodiversity. Such protection requires will, finance, legislation and education. Countries with different levels of economic development face different challenges and demands placed on resources including financial. Some mention of international agreements impacting developing countries is valid. Please use level descriptors 2 30

This question in 8291/21 May/June 2019

5 Fig. 5.1 shows details of the tropical rainforests in West and Central Africa. Key tropical rainforests Africa The African tropical rainforests are known for high levels of biodiversity, including more than 600 tree species and 10 000 animal species. Elephants, gorillas and large herbivores keep the number of small trees very low which reduces competition for large trees. But in areas where these animals have been depleted by hunting, forests tend to be denser with small trees. Mature forests in Africa store huge volumes of carbon in their vegetation and tree trunks, serving as an important buffer against climate change. Fig. 5.1 (a) Describe the human activities which can lead to the loss of tropical rainforests such as those in Fig. 5.1. [10] (b) Explain how ecotourism can lead to the successful conservation of rainforests. Using examples, assess the advantages and disadvantages of ecotourism projects. [30] [Total: 40]

40 marks

Mark scheme: 5(a) Biggest human activity is clearance of forest for subsistence farming activities (including charcoal burning and fuel wood collection), palm oil plantations, urban expansion and mining. Some of these are illegal activities. Industrial logging is also a large factor, and the clearance for logging roads also increases hunting and larger farming opportunities (palm oil, sugar and rubber) which affect the rate of loss. Increased hunting and poaching alter the balance of species and alters the structure of the rainforest plants in terms of height and species. Burning for clearance also occurs. Please use level descriptors 1 10 5(b) The question requirements are: • To show understanding of the principles underlying ecotourism • To apply the principles of ecotourism to rainforests • To assess the relative successes of ecotourism projects Ecotourism is defined as environmentally responsible travel to natural areas, in order to enjoy and appreciate nature (and accompanying cultural features, both past and present) that promote conservation, have a low visitor impact and provide for beneficially active socio-economic involvement of local peoples. Most tourism in natural areas today is not ecotourism and is not, therefore, sustainable. Ecotourism is distinguished by its emphasis on conservation, education, traveller responsibility and active community participation. Specifically, ecotourism possesses the following characteristics: • Conscientious, low-impact visitor behaviour • Sensitivity towards, and appreciation of, local cultures and biodiversity • Support for local conservation efforts • Sustainable benefits to local communities • Local participation in decision-making • Educational components for both the traveller and local communities Applying these underlying principles to rainforests such as the Congo can help conserve the rainforest. 30 Question Answer Marks 5(b) Advantages include preservation of species and the environment of the area, increased prosperity of the locals through involvement in the ecotourism, improved education, improved understanding of environment. Disadvantages include disturbance of the wildlife, damage and erosion caused by tourist numbers, increased carbon footprint of travellers, cultural erosion of traditional ways of life, travel industry is sensitive to world economic influences and this could lead to failure of projects. Please use level descriptors 2 Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level Section B descriptor levels: level descriptors 1 Level one, 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer Level two, 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance Level three, 1–4 marks The response: • may contain errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Section B descriptor levels: level descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain poor balanced of content • may not contain evaluations • make limited use of relevant vocabulary Section B descriptor levels: Level five, 1–5 marks • fulfil a few requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

This question in 8291/21 May/June 2019

2 (a) The Great Barrier Reef is the world’s largest coral reef ecosystem. Fig. 2.1 shows the areas of the Great Barrier Reef monitored for bleaching in 2016 and 2017. Bleaching events turn the coral white due to the death of algae within coral. 2016 2017 N N Key most severe bleaching no or negligible bleaching Cairns Cairns Townsville Townsville Mackay Mackay 0 500 0 500 km km Fig. 2.1 (i) Describe two differences in the coral bleaching in 2016 and 2017 shown in Fig. 2.1. … … … … [2] (ii) Suggest two human activities which could directly cause damage to the coral. … … … … [2] (b) Fig. 2.2 is an extract from a report about coral bleaching of the Great Barrier Reef. Aerial surveys have found that two severe bleaching events in 2016 and 2017 affected two- thirds of the Great Barrier Reef. This phenomenon is mainly caused by increases to the sea surface temperature. Scientists using aerial surveys recorded bleaching at 800 individual coral reefs across 8,000 km. The results show the two consecutive mass bleaching events have affected a 1,500 km stretch, leaving only the reef’s southern third undamaged. The 2017 event spread further south, and was most intense in the middle section of the Great Barrier Reef. The 2017 mass bleaching, second in severity only to 2016, has occurred even in the absence of an El Niño event. Mass coral bleaching has occurred on the reef four times in recorded history. Fig. 2.2 (i) With reference to Fig. 2.2, explain what has led to the mass bleaching of the coral. … … … … [2] (ii) Suggest two ways, other than aerial surveys, scientists monitor changes in the coral reef. 1 … … 2 … … [2] (c) Fig. 2.3 is part of a food web for a coral reef such as the Great Barrier Reef. sea eagle reef shark sea turtle large fish jellyfish sea horse small fish molluscs coral zooplankton krill phytoplankton Fig. 2.3 (i) With reference to Fig. 2.3, suggest the effects that an increase in jellyfish numbers might have on this coral reef food web. … … … … … … … … … [4] (ii) The Crown of Thorns Starfish is an invasive predatory species which feeds on coral. Suggest how an invasion by these starfish might affect the food web shown in Fig. 2.3. … … … … … … … … [4] (iii) Suggest strategies to control the population of the Crown of Thorns Starfish. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) more areas of severe bleaching; previously affected areas (2016) are larger; damage spreading further north / south; southern area remains undamaged; max 2 2(a)(ii) diving; boating damage (contact); boating damage from nets / lines / anchors; pollution; named pollutant; coral mining; overfishing; max 2 2(b)(i) increased global warming / climate change; leads to rising sea temperatures; El Nino affects sea temperature; and leads to increased bleaching; complex chemical changes in the water lead to increased coral bleaching; acidification; max 2 2(b)(ii) satellite imaging; aerial photos; dive monitoring; monitoring of sea temperatures; colour chart testing; max 2 2(c)(i) increased phytoplankton; decreased zooplankton; reduction in small fish; reduction in molluscs; increased coral; food web becomes unbalanced; likely increase in top predators / reef shark / sea eagle; max 4 Question Answer Marks 2(c)(ii) damage / kill large areas of coral; reduce biodiversity of coral; less coral available for secondary consumers; reduction in species in the food web; named example; less food for top predators; loss of habitat / shelter for species in the food web; max 4 2(c)(iii) collection / removal by divers; allows reduction of numbers and provides opportunities to inspect the progress / state of the reef; kill by chemical injections; some concern over chemicals entering the food web; disrupt reproduction with hormones; population gradually declines as reproduction rate falls; introduce predatory fish; these eat the starfish but could interfere with the food web; a robot has been designed to catch and inject the starfish; less need for human interaction with the reef and the species there; max 4

This question in 8291/22 May/June 2019

2 (a) The Great Barrier Reef is the world’s largest coral reef ecosystem. Fig. 2.1 shows the areas of the Great Barrier Reef monitored for bleaching in 2016 and 2017. Bleaching events turn the coral white due to the death of algae within coral. 2016 2017 N N Key most severe bleaching no or negligible bleaching Cairns Cairns Townsville Townsville Mackay Mackay 0 500 0 500 km km Fig. 2.1 (i) Describe two differences in the coral bleaching in 2016 and 2017 shown in Fig. 2.1. … … … … [2] (ii) Suggest two human activities which could directly cause damage to the coral. … … … … [2] (b) Fig. 2.2 is an extract from a report about coral bleaching of the Great Barrier Reef. Aerial surveys have found that two severe bleaching events in 2016 and 2017 affected two- thirds of the Great Barrier Reef. This phenomenon is mainly caused by increases to the sea surface temperature. Scientists using aerial surveys recorded bleaching at 800 individual coral reefs across 8,000 km. The results show the two consecutive mass bleaching events have affected a 1,500 km stretch, leaving only the reef’s southern third undamaged. The 2017 event spread further south, and was most intense in the middle section of the Great Barrier Reef. The 2017 mass bleaching, second in severity only to 2016, has occurred even in the absence of an El Niño event. Mass coral bleaching has occurred on the reef four times in recorded history. Fig. 2.2 (i) With reference to Fig. 2.2, explain what has led to the mass bleaching of the coral. … … … … [2] (ii) Suggest two ways, other than aerial surveys, scientists monitor changes in the coral reef. 1 … … 2 … … [2] (c) Fig. 2.3 is part of a food web for a coral reef such as the Great Barrier Reef. sea eagle reef shark sea turtle large fish jellyfish sea horse small fish molluscs coral zooplankton krill phytoplankton Fig. 2.3 (i) With reference to Fig. 2.3, suggest the effects that an increase in jellyfish numbers might have on this coral reef food web. … … … … … … … … … [4] (ii) The Crown of Thorns Starfish is an invasive predatory species which feeds on coral. Suggest how an invasion by these starfish might affect the food web shown in Fig. 2.3. … … … … … … … … [4] (iii) Suggest strategies to control the population of the Crown of Thorns Starfish. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) more areas of severe bleaching; previously affected areas (2016) are larger; damage spreading further north / south; southern area remains undamaged; max 2 2(a)(ii) diving; boating damage (contact); boating damage from nets / lines / anchors; pollution; named pollutant; coral mining; overfishing; max 2 2(b)(i) increased global warming / climate change; leads to rising sea temperatures; El Nino affects sea temperature; and leads to increased bleaching; complex chemical changes in the water lead to increased coral bleaching; acidification; max 2 2(b)(ii) satellite imaging; aerial photos; dive monitoring; monitoring of sea temperatures; colour chart testing; max 2 2(c)(i) increased phytoplankton; decreased zooplankton; reduction in small fish; reduction in molluscs; increased coral; food web becomes unbalanced; likely increase in top predators / reef shark / sea eagle; max 4 Question Answer Marks 2(c)(ii) damage / kill large areas of coral; reduce biodiversity of coral; less coral available for secondary consumers; reduction in species in the food web; named example; less food for top predators; loss of habitat / shelter for species in the food web; max 4 2(c)(iii) collection / removal by divers; allows reduction of numbers and provides opportunities to inspect the progress / state of the reef; kill by chemical injections; some concern over chemicals entering the food web; disrupt reproduction with hormones; population gradually declines as reproduction rate falls; introduce predatory fish; these eat the starfish but could interfere with the food web; a robot has been designed to catch and inject the starfish; less need for human interaction with the reef and the species there; max 4

This question in 8291/23 May/June 2019

1 (a) Fig. 1.1 is a photograph of a desert biome. Fig. 1.1 (i) State the two main abiotic factors which control the distribution of the biome shown in Fig. 1.1. 1 … 2 … [2] (ii) Describe the effect that one abiotic factor has on a desert soil. … … … … [2] (iii) Table 1.1 contains six soil characteristics. Identify two characteristics of a soil in a desert biome. Place a tick (3) in the boxes next to your choices. Table 1.1 characteristic present in desert soil very little leaf litter high soil moisture content silt and clay layers thick, dry horizon over parent rock thick humus layer rapid rate of decomposition [2] (b) Fig. 1.2 shows part of a desert food web. hawks desert foxes large lizards scorpions snakes kangaroo rat insects small lizards desert plants Fig. 1.2 (i) State the trophic level of each of the following organisms in Fig. 1.2. scorpion … desert plant … kangaroo rat … [3] (ii) Explain one possible effect of the loss of insects on the food web shown in Fig. 1.2. … … … … [2] (iii) State which trophic level has the least energy in a pyramid of energy. … [1] (iv) State which type of organism is essential for the breakdown of organic matter in an ecosystem. … [1] (v) Desertification is the process of desert biomes spreading into previously fertile areas. Describe two human activities responsible for desertification. … … … … … … … … [4] (vi) Suggest reasons why desertification is increasing. … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) temperature; water; 2 1(a)(ii) appropriate description of chosen factor (from water, sunlight, oxygen, or temperature) on desert soil; effect of chosen factor on desert soil; 2 1(a)(iii) ; ; characteristic present in desert soil very little leaf litter 9 high soil moisture content silt and clay layers thick dry horizon over parent rock 9 thick humus layer 2 1(b)(i) scorpion – secondary consumer; desert plant – producer; kangaroo rat – primary consumer; 3 1(b)(ii) fewer scorpions; due to less food; large lizards have less food; large lizards prey more on small lizards; leading to fewer small lizards; max 2 2 1(b)(iii) hawks / desert foxes / top predators; 1 1(b)(iv) decomposers; 1 Question Answer Marks 1(b)(v) expansion of agricultural land; destroys original habitats; over-use of agricultural land; destroys the soil structure / affects soil fertility; poor irrigation practices; causes aridity; deforestation; disrupts local water cycle / destroys habitats / leads to soil aridity; over-grazing; loss of plants leads to aridity; max 4 4 1(b)(vi) increasing urbanisation / increasing human activities, e.g. logging; increasing global warming; climate change leading to increasing weather extremes; increasing drought / reduced precipitation; max 3 3

This question in 8291/21 Oct/Nov 2019

1 (a) Fig. 1.1 is a diagram showing energy flow through an ecosystem. energy from the sun gross primary production respiration net primary production feeding consumers respiration death excretion X respiration Fig. 1.1 (i) State what X represents in Fig. 1.1. … [1] (ii) Use Fig. 1.1 to explain the difference between gross primary production and net primary production. … … … … [2] (iii) State two abiotic factors that affect the rate of primary productivity. 1. … 2. … [2] (iv) Name the process by which primary producers synthesise organic molecules using energy from the sun. … [1] (v) State the biome with the highest net primary productivity. … [1] (b) Fig. 1.2 is a pyramid of biomass for a temperate deciduous forest food chain. wolves (420 kg / km2) red foxes (2 100 kg / km2) snowshoe hares (20 925 kg / km2) grass (2.0925 x 107 kg / km2) Fig. 1.2 (i) State the primary consumer shown in Fig. 1.2. … [1] (ii) Describe what a pyramid of biomass shows. … … … … [2] (iii) Explain the shape of the pyramid of biomass shown in Fig. 1.2. … … … … [2] (iv) If the population of wolves decreased, state and explain two changes that could occur in the food chain shown in Fig. 1.2. … … … … … … … … [4] (c) Fig. 1.3 shows the nutrient flows and stores for a temperate deciduous forest. biomass precipitation Key Y size of circle proportional to the size of the nutrient store litter width of arrow proportional to the amount of soil nutrient flow leaching run-off weathering Fig. 1.3 (i) Describe the method by which nutrients flow in the process labelled Y on Fig. 1.3. … [1] (ii) With reference to Fig. 1.3, describe the changes which might occur to the forest nutrient stores and flows as a result of deforestation. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) decomposition / decay; 1 1(a)(ii) (gross primary production) is all the production; minus the energy used in respiration; 2 1(a)(iii) temperature; moisture / water; sunlight; carbon dioxide; max 2 2 1(a)(iv) photosynthesis; 1 1(a)(v) tropical rainforest; 1 1(b)(i) (snowshoe) hare; 1 1(b)(ii) the mass of organism / species; at each trophic level; the amount of energy available; at each trophic level; the transfer of energy; between trophic levels; max 2 2 1(b)(iii) only energy stored; is transferred; energy is lost; as heat / due to respiration / other wastes; max 2 2 Question Answer Marks 1(b)(iv) red foxes would increase; because of less predation; snowshoe hares would suffer more predation; population would decrease; resulting in more grass; max 4 4 1(c)(i) absorption; 1 1(c)(ii) large amount of stored biomass lost / reduced; as trees are felled; less input / flow into the litter; litter store will decrease; run-off will increase; less flow from litter to soil; less flow from soil to biomass; weathering of soil increases; max 3 3

This question in 8291/22 Oct/Nov 2019

3 Fig. 3.1 is two photographs showing farming in countries at different levels of economic development. photograph A (harvesting potatoes) photograph B (harvesting grain) Fig. 3.1 (a) Describe the effects that the farming shown in Fig. 3.1 might have on local habitats. [10] (b) Using examples, assess the methods used to maintain a sustainable food supply in countries at different levels of economic development. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Subsistence farming: Methods lead to loss of fertility of soils and loss of local habitats through clearance of land for crops, slash and burn, reduction of available water as land becomes more arid. Mechanised farming; Large areas of land cleared for monoculture removes habitats, soil compacted by machinery, fertility maintained artificially but can lead to problems such as eutrophication of water resources. please use level descriptors 1 10 Question Answer Marks 3(b) The question requirements are: • to demonstrate understanding of the different pressures to maintain food supply sustainably • to demonstrate understanding of the issues faced by countries with different levels of economic development • to assess the methods used to provide food sustainably. Indicative content: Different levels of economic development present different problems with regard to the sustainable production food. Also, population size is a factor linked to economic development. Lack of money means a lack of commercial fertiliser and poorer quality seed or crop plants available to purchase, e.g. cloning of date palms leads to cheaper plants with a guaranteed product. Subsistence level farming is risky and very prone to changes in weather patterns such as drought – leading to poor harvests and lack of money to buy livestock fodder and nothing left over to buy the requirements for next season. Declining soil means the need to destroy more habitat to grow sufficient produce to survive. Such countries lack the infrastructure to transport materials easily. Farming methods could be described as traditional. In more economically developed countries farming is industrial and mechanised. Overproduction can be an issue. Money means quality seeds and crops can be purchased and the infrastructure is in place to easily transport goods and produce. There is also the potential for farming to co-exist with natural habitats because of productivity, e.g. organic farming, maintaining hedgerows and wildlife strips. please use level descriptors 2 30

This question in 8291/22 Oct/Nov 2019

2 (a) Fig. 2.1 is a graph showing the demand for water by sector in China for 2005, 2015 and predicted demand for 2030. Key domestic industry 818 agriculture 133133 667 8888 555 265265 6868 194194 annual water 129129 usage billion m3 420420 358358 385385 2005 2015 2030 year Fig. 2.1 (i) State the sector shown in Fig. 2.1 which is predicted to have the largest increase in demand for water from 2005 to 2030. … [1] (ii) Suggest reasons for the increase in demand for water by the sector stated in (a)(i). … … … … … … [2] (iii) Describe four ways China might manage the increase in demand for water shown in Fig. 2.1. … … … … … … … … [4] (iv) Fig. 2.2 shows how the predicted demand for water will affect the water supply in different regions of China in 2030. Key surplus supply moderate shortage severe shortage Song Northwest Huang Liao Hai Huai Southwest Pearl Yangtze Southeast Fig. 2.2 Describe the impact of the predicted 2030 water supply for the Yangtze region of China. … … … … … … … … [4] (b) Fig. 2.3 is an extract from an English-language webpage published in China. Jade Dragon Snow Mountain Shrinks The melting of the glaciers at Jade Dragon Snow Mountain, in Lijiang city of China’s southwest Province, has accelerated. Fig. 2.3 (i) Suggest one reason for the accelerated melting of the glaciers described in Fig. 2.3. Explain your answer. … … … … [2] (ii) Glaciers and ice caps store more than 68% of the Earth’s freshwater. Describe three impacts of glaciers melting. … … … … … … [3] (c) Describe the impacts of pollution due to human activity on a named water store. Include the source of this pollution in your answer. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) industry; 1 2(a)(ii) growing population; greater consumer demands; increasing industrialisation; growing economy; increasing manufacture for export; max 2 2(a)(iii) build reservoirs; use desalination methods; improve infrastructure; establish water grid system to move water to places in need; import water; reduce waste; education; max 4 2(a)(iv) severe shortage predicted; domestic use affected; (less) for drinking / washing / valid example; Industrial use affected; (less) for use in cooling / manufacturing processes / valid example; Agricultural use affected; (less) for watering crops / livestock / valid example; max 4 2(b)(i) increased release of greenhouse gases; accumulate in upper atmosphere; absorb infra-red / heat; emitted back to Earth; increasing temperatures; max 2 Question Answer Marks 2(b)(ii) affect the supply of drinking water / irrigation water; could lead to drought conditions; due to loss of annual melt flow; leads to rising sea levels; coastal and low-lying areas at risk; loss of reflective areas / decrease in albedo affects global temperatures; contributing to global warming; max 3 2(b)(c) named pollutant e.g. fertiliser / nutrient enrichment / sewage / named chemical; relevant method of pollution e.g. farming run-off / sewage pipes into the sea / chemical spills; relevant environmental impact or impacts; relevant health impact or impacts; 4

This question in 8291/21 May/June 2020

4 Fig. 4.1 shows the major types of waste found in marine ecosystems and information about the potential threats. types of waste found in marine ecosystems 1.20% 3.80% 6.00%6.00% 6.00%6.00% Key plastic clothing paper metal wood 83%83% Threats from marine debris Over 100 million marine animals are killed each year due to plastic waste in the ocean. It is estimated that there are 100 million tonnes of plastic waste in oceans around the world. It is expected that at least another 60 billion kilograms will be produced every year. In some areas, the build-up of plastic waste is estimated to cover 8 million square kilometres, approximately the area of the USA. Eighty percent of the plastic waste comes from land. It is washed out to sea from our roads, storm drains, rivers and beaches. Fig. 4.1 (a) With reference to Fig. 4.1, suggest the likely effects of plastic waste on marine species. [10] (b) Using examples evaluate the strategies used to manage the problems caused by different sources of marine pollution. [30] [Total: 40]

40 marks

Mark scheme: 4(a) Plastics in the form of bottles, bags (look like jellyfish to a turtle), fishing nets and lines and plastic pellets are the main types. Death caused by ingesting plastics, accumulating in the digestive systems, reducing the ability to feed, or reducing the amount eaten, plastic becomes entangled around limbs impeding mobility. Plastics accumulate in huge masses in the centre of ocean gyres making passage difficult and interfering with migration routes. Plastics interfere with reproduction. Plastics can reduce visibility and reduce the chances of successful predation and reproduction. 10 4(b) The question requirements are: • to show understanding of the range of marine pollutants both point and non-point in origin • to suggest strategies to reduce the pollution of the marine environment • to evaluate the success of such strategies. Indicative content: Point sources can be traced and are usually factories, oil refineries, paper mills and farms discharging waste into water bodies or via sewage treatment plants. Also, there is direct dumping from vessels. Non-point sources are harder to trace and are usually the result of run-off water from rainfall or snow melt collecting pollutants as they flow into the water ways. Plastics and chemicals from landfill sites. Strategies for point sources include regulation and legislation with sources expected to use technology to clean effluent before it enters the water. Licensing schemes exist to control release of pollutants. Fines for breaches of regulations. Strategies for non-point include education to encourage people to not allow accidental spills of the pollutants and to discourage illegal dumping. Controls over landfills to ensure the plastics are dealt with and not allowed to leach into the waterways and hence the seas Encouraging the reduction in packaging in consumer goods, the charging for plastic bags at supermarkets, encouraging people to cut up plastics such as those rings from a six pack of cans. Encouraging the removal of plastic micro-beads from cosmetics and related products. Making oil tankers more secure from spills such as double hulls, and increasing legislation with regards to safety in the off- shore oil industry. Organising clean-up campaigns, NGOs have campaigns and publicity to educate and inform. Named examples such as Greenpeace and Surfers against sewage. 30 Please Use Level Descriptors 1 Please Use Level Descriptors 2

This question in 8291/21 May/June 2020

5 Fig. 5.1 shows the area of susceptible drylands in each continent, and the main causes of soil deterioration in these areas. 0.9% 5.4% 39.1% 41.5% 7.7 11.7% % Europe 34.8% North 99.4 km2 America 32.1% 79.5 km2 18.4% Asia 52.1% 30.1% 370.3 km2 11.5% 33.1% 26.1% South 16.9% America 4.8% 79.1 km2 40.7% 5.8% 5.5 14.7% Africa % 319.4 km2 57.8% Key Oceania 19.5% cause of soil deterioration 87.5 km2 grazing agriculture deforestation 89.7% other Fig. 5.1 (a) With reference to Fig. 5.1, describe the regional variation of the causes of soil deterioration. Suggest reasons for the regional variation described. [10] (b) Using examples, discuss how countries with different levels of economic development might prevent the loss of local habitats as a result of agricultural practices. [30] [Total: 40]

40 marks

Mark scheme: 5(a) Overgrazing is responsible for most soil degradation except for North and South America. Next most responsible is deforestation particularly significant in Asia, South America and Europe. Differences are due to the nature of the lands available, the increasing aridity of the areas and the growing populations putting particular pressures on the lands in some areas, whether or not legislation and enforcement protects areas from e.g. clearance / burning etc. The difference in pressures from subsistence and mechanised industrial-level farming. 5(b) The question requirements are: • to show understanding of the need to increase agricultural production • to demonstrate how this impacts on soil quality and local habitats • to suggest how this can be managed in countries with differing levels of financial development. Indicative content: Subsistence farming in countries with low economic development leads to loss of habitats. As soil quality falls farmers who can’t afford to use fertilisers clear new land instead (slash and burn) and destroy habitats. Increasing degradation of soil promotes desertification, as soil becomes increasingly arid farming becomes increasingly difficult. Such countries lack the money for infrastructure projects such as irrigation schemes and may come to rely on funding from elsewhere increasing debt. As a consequence, despite legislation the environment is not protected very successfully. Countries with higher levels of income can farm intensively and afford the fertilisers to maintain the soil quality. As a result, they are less likely to destroy local habitats through encroachment and have the luxury of infrastructure and to be able to support environmental protection schemes. 30 Please Use Level Descriptors 2 Please Use Level Descriptors 1 Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level Section B descriptor levels: Level Descriptors 1 Level one, 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer Level two, 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance Level three, 1–4 marks The response: • may contain errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Section B descriptor levels: Level Descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain poor balanced of content • may not contain evaluations • make limited use of relevant vocabulary Section B descriptor levels: Level five, 1–5 marks • fulfil a few requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

This question in 8291/21 May/June 2020

2 (a) Fig. 2.1 shows the distribution of the tundra biome. Arctic Circle, 66.5 °N Tropic of Cancer, 23.5 °N Equator Tropic of Capricorn, 23.5 °S Key tundra biome Fig. 2.1 (i) Describe the distribution of the tundra biome shown in Fig. 2.1. … … … … [2] (ii) State the two main abiotic factors which contribute to the distribution of the tundra biome shown in Fig. 2.1. 1 … 2 … [2] (b) Fig. 2.2 is a food chain found in the tundra biome. Lichen Caribou Arctic Wolf Fig. 2.2 (i) State what is represented by the arrows in the food chain shown in Fig. 2.2. … … … … [2] (ii) Suggest why food chains in the tundra biome are short. … … … … [2] (c) Fig. 2.3 is an extract from a local news webpage. With more people moving to the tundra to work in mines and on oil rigs, more towns and roads have been built. The building of other structures, such as the Trans-Alaska Oil Pipeline, have caused disruption to species such as the Arctic Wolf. In addition, pesticides have been used to control large swarms of insects, which migrating birds rely on for food in the tundra. Fig. 2.3 (i) Suggest three ways in which human activities in Fig. 2.3 have caused disruption to the habitat of the Arctic Wolf. … … … … … … [3] (ii) Explain why the use of pesticides to control insect populations might lead to the death of Arctic birds of prey. … … … … … … [3] (d) Fig. 2.4 is an extract from an environmental journal. Permafrost is a characteristic of the tundra biome. The soil is frozen to a considerable depth meaning that trees cannot grow there. The permafrost acts as a store of water, methane and carbon dioxide. The winter months of January and February 2018 saw a change in weather patterns with unusually high temperatures in the arctic tundra, leading to melting of some of the permafrost. Fig. 2.4 Explain how the melting of some of the permafrost might affect coastal communities and global weather patterns. … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) near the North Pole / top of the world; above 60 °N latitude; on or close to the Arctic circle; northern Canada, Alaska, northern Scandinavia and Siberia; 2(a)(ii) temperature; moisture / rainfall / precipitation; 2 Question Answer Marks 2(b)(i) the transfer of energy; from prey to predator / from one organism to another / through feeding; 2 2(b)(ii) harsh environment; short summer means abundance is very short lived; means food chains are fragile; populations are (relatively) small; biodiversity is (relatively) low; Less energy available to higher levels max 2 2(c)(i) hunting / shooting; roads disrupt territories; risk of collisions; settlements disrupt prey animals’ behaviour; populations decline / relocate; poisoning (deliberate / accidental); bioaccumulation; max 3 2(c)(ii) insects contain the poison; insectivores ingest this poison; passes along the food chain; becomes more concentrated; bioaccumulation; top predator gets lethal / damaging dose of insecticide; gyrfalcons die / have reduced reproduction; max 3 Question Answer Marks 2(d) water stored as permafrost released; leads to more water in rivers and streams; increasing likelihood of flooding; water runs into the oceans; leading to rising sea levels; causing flooding of coastal communities; increasing salinisation of coastal soils / land; melting of the permafrost releases carbon dioxide store / methane; this is no longer locked up / released into the atmosphere; extra carbon dioxide / methane leads to increase in greenhouse gases; contributes to global warming; more extreme weather patterns / global weather pattern is uncertain as could lead to feedback loops; computer models vary in their predictions of feedback loops; more storms leading to coastal damage; decrease albedo as permafrost melts; max 6

This question in 8291/22 May/June 2020

4 Fig. 4.1 is a series of maps showing the spread of lionfish, an invasive marine species, following the release of a single pair in Florida, USA in 1985. The lionfish is native to the coasts of Indo-Pacific Asia. N N N 0 400 0 400 0 400 km km km Atlantic Atlantic Atlantic ocean ocean ocean Pacific Pacific Pacific ocean ocean ocean 1985 1995 2005 N N 0 400 0 400 km km Atlantic Atlantic ocean ocean Key areas where the lionfish is found Pacific Pacific land ocean ocean ocean 2010 2014 Fig. 4.1 (a) Describe the spread of the lionfish shown in Fig. 4.1. [10] (b) Explain how an invasive fish species such as the lionfish can cause disruption to the habitat and to native species. Assess strategies used to manage the control of invasive species in different habitats. [30] [Total: 40]

40 marks

This question in 8291/22 May/June 2020

2 (a) Fig. 2.1 shows the distribution of the tundra biome. Arctic Circle, 66.5 °N Tropic of Cancer, 23.5 °N Equator Tropic of Capricorn, 23.5 °S Key tundra biome Fig. 2.1 (i) Describe the distribution of the tundra biome shown in Fig. 2.1. … … … … [2] (ii) State the two main abiotic factors which contribute to the distribution of the tundra biome shown in Fig. 2.1. 1 … 2 … [2] (b) Fig. 2.2 is a food chain found in the tundra biome. Lichen Caribou Arctic Wolf Fig. 2.2 (i) State what is represented by the arrows in the food chain shown in Fig. 2.2. … … … … [2] (ii) Suggest why food chains in the tundra biome are short. … … … … [2] (c) Fig. 2.3 is an extract from a local news webpage. With more people moving to the tundra to work in mines and on oil rigs, more towns and roads have been built. The building of other structures, such as the Trans-Alaska Oil Pipeline, have caused disruption to species such as the Arctic Wolf. In addition, pesticides have been used to control large swarms of insects, which migrating birds rely on for food in the tundra. Fig. 2.3 (i) Suggest three ways in which human activities in Fig. 2.3 have caused disruption to the habitat of the Arctic Wolf. … … … … … … [3] (ii) Explain why the use of pesticides to control insect populations might lead to the death of Arctic birds of prey. … … … … … … [3] (d) Fig. 2.4 is an extract from an environmental journal. Permafrost is a characteristic of the tundra biome. The soil is frozen to a considerable depth meaning that trees cannot grow there. The permafrost acts as a store of water, methane and carbon dioxide. The winter months of January and February 2018 saw a change in weather patterns with unusually high temperatures in the arctic tundra, leading to melting of some of the permafrost. Fig. 2.4 Explain how the melting of some of the permafrost might affect coastal communities and global weather patterns. … … … … … … … … … … [6] [Total: 20]

20 marks

Mark scheme: 2(a)(i) near the North Pole / top of the world; above 60 °N latitude; on or close to the Arctic circle; northern Canada, Alaska, northern Scandinavia and Siberia; 2(a)(ii) temperature; moisture / rainfall / precipitation; 2 Question Answer Marks 2(b)(i) the transfer of energy; from prey to predator / from one organism to another / through feeding; 2 2(b)(ii) harsh environment; short summer means abundance is very short lived; means food chains are fragile; populations are (relatively) small; biodiversity is (relatively) low; Less energy available to higher levels max 2 2(c)(i) hunting / shooting; roads disrupt territories; risk of collisions; settlements disrupt prey animals’ behaviour; populations decline / relocate; poisoning (deliberate / accidental); bioaccumulation; max 3 2(c)(ii) insects contain the poison; insectivores ingest this poison; passes along the food chain; becomes more concentrated; bioaccumulation; top predator gets lethal / damaging dose of insecticide; gyrfalcons die / have reduced reproduction; max 3 Question Answer Marks 2(d) water stored as permafrost released; leads to more water in rivers and streams; increasing likelihood of flooding; water runs into the oceans; leading to rising sea levels; causing flooding of coastal communities; increasing salinisation of coastal soils / land; melting of the permafrost releases carbon dioxide store / methane; this is no longer locked up / released into the atmosphere; extra carbon dioxide / methane leads to increase in greenhouse gases; contributes to global warming; more extreme weather patterns / global weather pattern is uncertain as could lead to feedback loops; computer models vary in their predictions of feedback loops; more storms leading to coastal damage; decrease albedo as permafrost melts; max 6

This question in 8291/23 May/June 2020

4 Fig. 4.1 is a series of maps showing the spread of lionfish, an invasive marine species, following the release of a single pair in Florida, USA in 1985. The lionfish is native to the coasts of Indo-Pacific Asia. N N N 0 400 0 400 0 400 km km km Atlantic Atlantic Atlantic ocean ocean ocean Pacific Pacific Pacific ocean ocean ocean 1985 1995 2005 N N 0 400 0 400 km km Atlantic Atlantic ocean ocean Key areas where the lionfish is found Pacific Pacific land ocean ocean ocean 2010 2014 Fig. 4.1 (a) Describe the spread of the lionfish shown in Fig. 4.1. [10] (b) Explain how an invasive fish species such as the lionfish can cause disruption to the habitat and to native species. Assess strategies used to manage the control of invasive species in different habitats. [30] [Total: 40]

40 marks

This question in 8291/23 May/June 2020

5 Fig. 5.1 shows sources of pollution in two rivers. sources of pollution in river A sources of pollution in river B Key agriculture sewage industry Fig. 5.1 (a) Describe the differences in the data for river A and river B. Suggest reasons for the differences shown in Fig. 5.1. [10] (b) Discuss the impact of raw sewage disposal on rivers, lakes and human health. Use examples in your answer. [30] [Total: 40]

40 marks

Mark scheme: 5(a) Raw sewage enters plant and is filtered by large screens to remove debris before entering a sedimentation tank where the heavier solid wastes can settle and are removed and dried or used in other ways. The liquid and lighter waste is transferred to filter beds where anaerobic bacteria digest the organic material over time and clean water is released, or, this is transferred to an activated sludge tank to be digested by anaerobic microbes to release clean water. please use level descriptors 1 Question Answer Marks 5(b) The question requirements are: • to show understanding for the need for sewage treatment and the environmental problems if it is not treated before release • to demonstrate knowledge of the health problems arising from sewage and sewage sludge • to show understanding of the environmental problems caused by the accidental disposal of sewage and sewage sludge. Indicative content: The impact of raw sewage in rivers is to lead to oxygen depletion and the loss of species. Sensitive indicator species are present or absent depending on the level of oxygen. The sewage can also be a source of disease for humans using the water for recreation. Sewage works receive all sorts of wastes from hospitals, farms, industry and domestic residences. As a result, this substance can contain high levels of pathogenic microbes, poisonous substances such as cadmium, cyanide, etc. The sludge is used as a fertiliser on cropland and as such is a potential hazard and may leach into the water from the land. The sludge is dumped in landfill where it can leach into groundwater, streams and rivers as well as aquifers leading to potential health risks. Credit references to algal blooms particularly those with toxic effects on animals. Assessment of health issues especially those where general outbreaks of illness, e.g. cholera has occurred following spillages or floods due to extreme environmental events. 30 please use level descriptors 2 Question Answer Marks Section B descriptor levels: Descriptor Award Mark Consistently meets the level criteria Mark at top of level Meets the criteria, but with some inconsistency Middle, mark to just below top mark Meets most of level criteria, but not all convincingly Just below middle, mark to just above bottom mark On the borderline of this level and the one below Mark at bottom of level Section B (part a), Level descriptors 1 8–10 marks The response: • contains few errors • shows a very good understanding of the question • shows a good use of data or the information provided, where appropriate • provides a balanced answer 5–7 marks The response: • may contain some errors • shows an adequate understanding of the question • shows some use of data or the information provided, where appropriate • may lack balance 1–4 marks The response: • may contains errors • shows limited understanding of the question • shows little or no use of data or the information, where appropriate • lacks balance Question Answer Marks Section B (part b): Level descriptors 2 Responses: Level one, 25–30 marks • fulfil all the requirements of the question • contain a very good understanding of the content required • contain a very good balance of content • contain substantial critical and supportive evaluations • make accurate use of relevant vocabulary Level two, 19–24 marks • fulfil most of the requirements of the question • contain a good understanding of the content required • contain a good balance of content • contain some critical and supportive evaluations • make good use of relevant vocabulary Level three, 13–18 marks • fulfil some requirements of the question • contain some understanding of the content required • may contain some limited balance of content • may contain brief evaluations • make some use of relevant vocabulary Level four, 6–12 marks • fulfil limited requirements of the question • contain limited understanding of the content required • may contain poorly balanced of content • may not contain evaluations • make limited use of relevant vocabulary Question Answer Marks Level five, 1-5 marks • fulfil a few of the requirements of the question • contain a very limited understanding of the content required • are likely to be unbalanced and undeveloped • evaluative statements are likely to be missing • make no use of relevant vocabulary

This question in 8291/21 Oct/Nov 2020

3 Fig. 3.1 shows the distribution of eutrophic and hypoxic (dead zone) areas of coastal waters of Europe. Iceland Finland Norway Sweden Denmark Baltic North Sea Sea Atlantic Ocean UK Poland Germany France N Black Sea ItalyItaly Spain GreeceGreece Key eutrophic area hypoxic (dead zone) area Mediterranean Algeria Sea Fig. 3.1 (a) Describe and suggest reasons for the distribution of eutrophic and hypoxic (dead zone) areas of coastal waters shown in Fig. 3.1. [10] (b) Using examples, assess the strategies used to reduce pollution which leads to eutrophic and hypoxic (dead zone) areas of coastal waters. [30] [Total: 40]

40 marks

Mark scheme: 3(a) The areas of coast highlighted are in either areas where a large population concentrated in cities has been passed by large rivers draining the wastes into the coastal areas or in particularly narrow and sheltered areas of sea such as around Denmark and Sweden and the Irish Sea. The hypoxic (dead zone) areas are mostly found at the mouths of rivers or river estuaries whereas the eutrophic areas are found in the more sheltered bays or enclosed seas or areas like the Venetian lagoon. The reasons for the coastal conditions include the large amount of sewage and agricultural waste from intensive cattle farms entering the rivers as they flow through eastern and western Europe and past the large cities along the way, as well as excess nitrogen and phosphate containing fertilisers running-off from the farmland. These accumulate in the mouths and estuaries of the rivers and the build-up leads to the conditions shown on the maps. Particularly vulnerable are sheltered areas 3(b) The requirements of the question are: • to describe the causes of eutrophication and hypoxic (dead zone) water • to discuss the international nature of these events • to describe strategies to control the release of the pollutants causing these conditions • to assess the relative success of the strategies. Indicative content: A brief description of the causes of eutrophication and hypoxia (dead zone) in coastal waters. A description of the different types of pollution involved, especially raw sewage, waste from intensive cattle farms, excess fertiliser run-off (rich in nitrate and phosphate), chemical and industrial waste. Some mention of point and non-point sources in connection with difficulty of monitoring. International nature of the problem as the rivers flow through several countries, highlighting a need for international cooperation and agreement (role of EU environmental legislation for example). Role of NGOs such as Surfers against Sewage. 30 please use level descriptors 1 Question Answer Marks 3(b) Strategies to include education of people to prevent dumping through ignorance, legislation to control release of raw sewage and cattle wastes, and to monitor the use of septic tanks in more rural areas, to control the excessive use of fertilisers. Fines for breaches of legislation. Build more and better treatment plants to prevent the present ones being overwhelmed and releasing raw sewage. Candidates should assess the relative successes of the different strategies described. please use level descriptors 2

This question in 8291/22 Oct/Nov 2020

4 Fig. 4.1 is a series of maps showing the extent of the tropical rainforest in Borneo from 1950 to 2020 with a pie chart showing some of the causes of the deforestation. 1950 1985 2000 2005 2010 2020 Key 0 200 tropical rainforest km causes of deforestation in Borneo Key large-scale farming logging subsistence farming wood pulp plantations mining / infrastructure / HEP fire Fig. 4.1 (a) With reference to Fig. 4.1, describe the changes to the extent of the tropical rainforest in Borneo between 1950 and 2020. Suggest the contribution made by the different causes shown. [10] (b) Assess local, national and international strategies to manage the causes and effects of deforestation. [30] [Total: 40]

40 marks

Mark scheme: 4(a) The rainforest started to disappear from the margins of the whole area though hung on in the east. The rate accelerated from 1985 through to 2010. Candidates should be aware of the date intervals shortening. From 2000 the rainforest shrank from the south towards the north. By 2020 the rate of disappearance appears to have slowed down though now the eastern area has gone. Agricultural practices are the largest contribution to the loss of rainforest with clearances for logging and pulp plantations being a big factor. Subsistence farming comprises 30% and this is reflected in the need for fertile soil so they move on and slash and burn new areas to grow their crops. Logging, mining and infrastructure have a small effect relatively – however there is no mention of illegal logging which probably has a significant contribution. please use level descriptors 1 Question Answer Marks 4(b) The question requirements are: • to describe the causes and effects of deforestation • to discuss the need for local, national and international agreements to control deforestation and the inherent difficulties • to assess the different strategies used to control deforestation. Indicative content: The effects are those of drying of soil, increased erosion and run-off and loss of fertility. The atmosphere changes and local climate is altered. Many species of animal and plant lose their habitat. Increased carbon dioxide as a result will contribute to global warming and climate change. A range of strategies to combat deforestation could be mentioned, with acknowledgement of the difficulties in obtaining agreements. Local strategies could use education, the provision of better methods of farming and soil fertility maintenance such as fertilisers, provision of seeds with guaranteed results – all to make subsistence farmers use the soils better. Encourage ecotourism with local involvement so they see the value in conserving the rainforest. National strategies include legislation and enforcement as well as supporting the local initiatives. There will be a role for NGOs in this. Cattle ranching is the largest contributor so needs to be regulated by national government, though it is hard to control. International agreements are difficult to achieve and to enforce for many political and geopolitical reasons. 30 please use level descriptors 2

This question in 8291/22 Oct/Nov 2020

3 Fig. 3.1 is a report about large-scale loss in flying insect numbers worldwide. Ecological Warning as Insect Population Numbers Fall The number of flying insects has fallen by 75% worldwide. Three-quarters of flying insects in nature reserves across Germany have vanished in 25 years, with serious implications for ecosystems. Humans are making vast areas of land inhospitable to most forms of life. If we lose the flying insects then ecosystems are going to collapse. Scientists suggest reducing the use of pesticides and fertilisers and reversing the draining of wetlands. Fig. 3.1 (a) With reference to Fig. 3.1, describe the causes and effects of the large-scale loss of flying insects. [10] (b) Using examples, evaluate strategies to manage the conservation of endangered species. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Causes Overuse / use of pesticides, loss of habitats, lack of food, loss of farm borders with flowers, loss of gardens, increasing effects of vehicles, drainage of wetlands, climate change. Effects Disruption of food chains/webs, lack of prey/food, lack of insect predators, lack of pollinators affects plants including human crops, and loss of detritus feeders increases detritus. 3(b) The requirements for this question are: • to demonstrate understanding that steps need to be taken to manage conservation of species • to demonstrate understanding of the different strategies to manage conservation of species • to evaluate strategies to manage conservation of species and give examples Candidates should provide detailed descriptions of a range of named examples of conservation strategies including conservation areas, national parks, habitat protection (SSSIs / ecological islands), and legislation to control the use of damaging chemicals such as pesticides including banning nicotinoid containing pesticides. Ecotourism is a potential solution. Putting species on e.g. the red list of endangered species. Candidates should assess the relative merits of these strategies. 30 please use level descriptors 1 please use level descriptors 2

This question in 8291/21 May/June 2021

4 Fig. 4.1 is a map showing the river Ganges as it flows from the Himalayas, through India and Bangladesh to the Bay of Bengal. Brahmaputra Kathmandu River Rishikesh G New Riha Gandak v g Jamuna h e r River Delhi G ar a River Dhaka anges Y Patna a m Kanpur Varanasi unaRiver Kolkata Prayagraj key river industry livestock farming bathing area industrial effluent from Kolkata port crop farming town / city Fig. 4.1 (a) With reference to Fig. 4.1, explain why the river Ganges has large areas of severely polluted water. [10] (b) To what extent can strategies to manage waste control reduce pollution of rivers? Use examples of local and regional policies. [30] [Total: 40]

40 marks

Mark scheme: 4(a) The river Ganges flows from the Himalayas through the top of India and into Bangladesh. On its route through India, it passes many large cities which pour a great deal of untreated sewage into the water leading to hypoxic (dead) zones downriver with areas deemed severe and critical. There is a lot of industry along the river especially polluting ones such as dyeing, leatherworks and sugar processing. The river also passes through agricultural areas and experiences eutrophic areas from the run-off from the fields. Candidates may also refer to disposal of bodies and bathing practices. 4(b) The requirements for this question are: • to demonstrate knowledge of the methods of pollution control • to show understanding of local and regional strategies • to assess the relative success of chosen examples. A range of different methods described including sewage treatment plants, legislation, education and reinforcement measures. Control of industrial discharge and steps to reduce agricultural run-off. Provision of infrastructure. Some understanding of the difficulties involved in implementation and enforcement and the difference between local and regional policies. Financial and political will issues. Assessment of the relative success of strategies. 30 please use level descriptors 1 please use level descriptors 2

This question in 8291/21 May/June 2021

1 Fig. 1.1 shows the international border between the Caribbean countries Haiti and Dominican Republic. international border Haiti Dominican Republic Fig. 1.1 (a) (i) Describe two differences between Haiti and Dominican Republic shown in Fig. 1.1. … … … … [2] (ii) Suggest two reasons for the differences in the amount of vegetation cover shown in Fig. 1.1. … … … … [2] (iii) Explain the effect of loss of vegetation cover on soil. … … … … … … [3] (iv) Explain why biodiversity decreases when vegetation cover is lost. … … … … [2] (b) Table 1.1 shows the percentage of an area covered by rainforest between 1985 and 2020. Table 1.1 year percentage of area covered by rainforest 1985 74 2000 58 2005 50 2010 44 2020 33 (i) Plot a scatter graph using the data from Table 1.1. Include a line of best fit. 100 90 80 70 60 percentage of area covered by 50 rainforest 40 30 20 10 0 1985 1990 1995 2000 2005 2010 2015 2020 year [3] (ii) Describe the change in the percentage of the area covered by rainforest between 1985 and 2020. … … [1] (c) Fig. 1.2 shows part of a food web for the Amazon Rainforest. jaguar (mammal) three toed sloth macaw howler monkey iguana (mammal) (bird) (mammal) (reptile) fire ant (insect) caterpillar (insect) plants Fig. 1.2 (i) State the number of trophic levels in the food web shown in Fig. 1.2. … … [1] (ii) State the trophic level that has the most energy. … [1] (iii) Explain why howler monkeys are both primary and secondary consumers. … … … … [2] (d) Explain the influence of light intensity on plant productivity. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 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

This question in 8291/22 May/June 2021

2 Fig. 2.1 is a diagram showing an effect of fertiliser pollution in water. N-P-K dead fish algal bloom excess use of chemical fertilisers dead algae inorganic salts dissolve in groundwater water Fig. 2.1 (a) (i) State the process occurring in the water shown in Fig. 2.1. … [1] (ii) Explain how excess use of fertilisers cause fish to die. … … … … … … … … [4] (iii) Describe strategies to reduce fertiliser use. … … … … … … … … [4] (b) Fig. 2.2 shows an aquifer. transpiration by vegetation unsaturated zone water table water table stream A B Key movement of water Fig. 2.2 (i) Using Fig. 2.2 state the type of aquifer labelled: A … B. … [2] (ii) Fertilisers are pollutants which affect groundwater stores. State three other pollutants which may affect groundwater stores. 1 … 2 … 3 … [3] (iii) Explain why aquifers do not recover quickly from pollution. … … … … [2] (iv) Suggest strategies to prevent the pollution of groundwater stores such as aquifers. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) eutrophication; 1 Question Answer Marks 2(a)(ii) fertiliser stimulates plant growth; algae grow rapidly; algae die due to lack of sunlight / light energy / due to competition for resources; (decomposing) bacteria / decomposers; use dead algae for nutrients; respiration; consumes oxygen; fish suffocate / die due to lack of oxygen; max 4 4 2(a)(iii) legislation; enforcement / fines; educate; follow instructions; crop rotation; mixed cropping; leguminous plants; fallow land; grow GM crops; which are adapted to poor soils; persuade farmers to use organic rather than inorganic fertilisers; because they are slower release; subsidies for organic farming; use of reed beds to filter water; max 4 4 2(b)(i) A – unconfined (aquifer); B – confined (aquifer); 2 Question Answer Marks 2(b)(ii) pesticides; oil and petroleum products; chemical industrial wastes; detergents; paint; acid; sewage; heavy metals; max 3 3 2(b)(iii) groundwater moves slowly; recharge takes a long time / is slow; little force behind the movement; chemicals take a long time to be washed away; max 2 2 2(b)(iv) encourage clean-up of e.g. oil spills; restrict pesticide / fertiliser use; encourage safe disposal of products; legislate / enforcement; educate; re-use / recycle water to reduce waste water; reduce drainage of wetlands; max 4 4

This question in 8291/22 May/June 2021

3 Fig. 3.1 shows a newspaper report about the construction of the Grand Ethiopian Renaissance Dam. One of the biggest dams in the world The Grand Ethiopian Renaissance Dam, on the River Nile near the Sudan border, will flood 1680 km2 of forest in northwest Ethiopia, displace approximately 20 000 people, and create a reservoir that will hold around 70 billion m3 of water. Red Sea Khartoum ERITREA Blue Lake SUDAN Nile Tana ETHIOPIA Grand Ethiopian Renaissance Dam Key international borders rivers city Fig. 3.1 (a) With reference to Fig. 3.1 describe the advantages and disadvantages of constructing large scale dams such as the Great Ethiopian Renaissance Dam. [10] (b) ‘Projects such as The Great Ethiopian Renaissance Dam could create conflicts over shared resources.’ Using examples, discuss the extent to which you agree with this statement. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Advantages Water supply is improved, potential for recreation, landscaping, power generation, improved economy and lifestyles, new habitat created, jobs Disadvantages Cost, potential for downriver problems, conflict with other countries, silting, affect seasonal agricultural floods, affect fish migration routes, destruction of habitats, displacement of people, noise and dust from construction, loss of agricultural land 3(b) The requirements for this question are: • to discuss the concept of shared resources • to demonstrate understanding that shared resources can lead to conflict • to evaluate the statement. Candidates should be aware of the difficulty of obtaining international agreements and be able to relate this to the shared resources concept such as the water in rivers that flow through more than one country. Other examples could include marine waters and fishing rights, and international protocols on pollution (shared air). Candidates should provide a balanced argument about the statement and suggest an opinion. 30 please use level descriptors 1 please use level descriptors 2

This question in 8291/22 May/June 2021

1 Fig. 1.1 shows the international border between the Caribbean countries Haiti and Dominican Republic. international border Haiti Dominican Republic Fig. 1.1 (a) (i) Describe two differences between Haiti and Dominican Republic shown in Fig. 1.1. … … … … [2] (ii) Suggest two reasons for the differences in the amount of vegetation cover shown in Fig. 1.1. … … … … [2] (iii) Explain the effect of loss of vegetation cover on soil. … … … … … … [3] (iv) Explain why biodiversity decreases when vegetation cover is lost. … … … … [2] (b) Table 1.1 shows the percentage of an area covered by rainforest between 1985 and 2020. Table 1.1 year percentage of area covered by rainforest 1985 74 2000 58 2005 50 2010 44 2020 33 (i) Plot a scatter graph using the data from Table 1.1. Include a line of best fit. 100 90 80 70 60 percentage of area covered by 50 rainforest 40 30 20 10 0 1985 1990 1995 2000 2005 2010 2015 2020 year [3] (ii) Describe the change in the percentage of the area covered by rainforest between 1985 and 2020. … … [1] (c) Fig. 1.2 shows part of a food web for the Amazon Rainforest. jaguar (mammal) three toed sloth macaw howler monkey iguana (mammal) (bird) (mammal) (reptile) fire ant (insect) caterpillar (insect) plants Fig. 1.2 (i) State the number of trophic levels in the food web shown in Fig. 1.2. … … [1] (ii) State the trophic level that has the most energy. … [1] (iii) Explain why howler monkeys are both primary and secondary consumers. … … … … [2] (d) Explain the influence of light intensity on plant productivity. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 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

This question in 8291/23 May/June 2021

2 Fig. 2.1 is a diagram showing an effect of fertiliser pollution in water. N-P-K dead fish algal bloom excess use of chemical fertilisers dead algae inorganic salts dissolve in groundwater water Fig. 2.1 (a) (i) State the process occurring in the water shown in Fig. 2.1. … [1] (ii) Explain how excess use of fertilisers cause fish to die. … … … … … … … … [4] (iii) Describe strategies to reduce fertiliser use. … … … … … … … … [4] (b) Fig. 2.2 shows an aquifer. transpiration by vegetation unsaturated zone water table water table stream A B Key movement of water Fig. 2.2 (i) Using Fig. 2.2 state the type of aquifer labelled: A … B. … [2] (ii) Fertilisers are pollutants which affect groundwater stores. State three other pollutants which may affect groundwater stores. 1 … 2 … 3 … [3] (iii) Explain why aquifers do not recover quickly from pollution. … … … … [2] (iv) Suggest strategies to prevent the pollution of groundwater stores such as aquifers. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 2(a)(i) eutrophication; 1 Question Answer Marks 2(a)(ii) fertiliser stimulates plant growth; algae grow rapidly; algae die due to lack of sunlight / light energy / due to competition for resources; (decomposing) bacteria / decomposers; use dead algae for nutrients; respiration; consumes oxygen; fish suffocate / die due to lack of oxygen; max 4 4 2(a)(iii) legislation; enforcement / fines; educate; follow instructions; crop rotation; mixed cropping; leguminous plants; fallow land; grow GM crops; which are adapted to poor soils; persuade farmers to use organic rather than inorganic fertilisers; because they are slower release; subsidies for organic farming; use of reed beds to filter water; max 4 4 2(b)(i) A – unconfined (aquifer); B – confined (aquifer); 2 Question Answer Marks 2(b)(ii) pesticides; oil and petroleum products; chemical industrial wastes; detergents; paint; acid; sewage; heavy metals; max 3 3 2(b)(iii) groundwater moves slowly; recharge takes a long time / is slow; little force behind the movement; chemicals take a long time to be washed away; max 2 2 2(b)(iv) encourage clean-up of e.g. oil spills; restrict pesticide / fertiliser use; encourage safe disposal of products; legislate / enforcement; educate; re-use / recycle water to reduce waste water; reduce drainage of wetlands; max 4 4

This question in 8291/23 May/June 2021

3 Fig. 3.1 shows a newspaper report about the construction of the Grand Ethiopian Renaissance Dam. One of the biggest dams in the world The Grand Ethiopian Renaissance Dam, on the River Nile near the Sudan border, will flood 1680 km2 of forest in northwest Ethiopia, displace approximately 20 000 people, and create a reservoir that will hold around 70 billion m3 of water. Red Sea Khartoum ERITREA Blue Lake SUDAN Nile Tana ETHIOPIA Grand Ethiopian Renaissance Dam Key international borders rivers city Fig. 3.1 (a) With reference to Fig. 3.1 describe the advantages and disadvantages of constructing large scale dams such as the Great Ethiopian Renaissance Dam. [10] (b) ‘Projects such as The Great Ethiopian Renaissance Dam could create conflicts over shared resources.’ Using examples, discuss the extent to which you agree with this statement. [30] [Total: 40]

40 marks

Mark scheme: 3(a) Advantages Water supply is improved, potential for recreation, landscaping, power generation, improved economy and lifestyles, new habitat created, jobs Disadvantages Cost, potential for downriver problems, conflict with other countries, silting, affect seasonal agricultural floods, affect fish migration routes, destruction of habitats, displacement of people, noise and dust from construction, loss of agricultural land 3(b) The requirements for this question are: • to discuss the concept of shared resources • to demonstrate understanding that shared resources can lead to conflict • to evaluate the statement. Candidates should be aware of the difficulty of obtaining international agreements and be able to relate this to the shared resources concept such as the water in rivers that flow through more than one country. Other examples could include marine waters and fishing rights, and international protocols on pollution (shared air). Candidates should provide a balanced argument about the statement and suggest an opinion. 30 please use level descriptors 1 please use level descriptors 2

This question in 8291/23 May/June 2021

1 (a) Table 1.1 shows the number of marine wildlife affected by marine debris in one year. Table 1.1 marine debris wildlife bottles cans lobster fishing fishing fishing plastic string other group and hooks lines nets bags and fish rope traps amphibians 1 0 0 0 3 1 6 0 1 birds 2 0 0 5 45 53 19 10 4 fish 5 1 2 1 48 11 11 7 3 invertebrates 6 2 1 1 14 12 6 13 0 mammals 0 0 0 3 6 1 6 6 1 reptiles 0 0 0 0 10 4 1 3 1 (i) State which wildlife group is affected by every type of marine debris shown in Table 1.1. … [1] (ii) State which wildlife group is most affected by marine debris shown in Table 1.1. … [1] (iii) Suggest two sources of the marine debris shown in Table 1.1. … … [2] (iv) Calculate the percentage of all mammals in Table 1.1 affected by plastic bags. … % [1] (b) Fig. 1.1 shows part of an ocean food web. killer whale tiger shark green sea turtle leatherback sea turtle squid jellyfish shrimp zooplankton sea grass phytoplankton Fig. 1.1 (i) State what the arrows in the food web shown in Fig. 1.1 represent. … … [1] (ii) Sea turtles are under threat because of plastic bag pollution in the sea. The turtles mistake the bags for jellyfish. Explain the effects of a reduction in sea turtle numbers on the food web shown in Fig. 1.1. … … … … … … … … [4] (iii) Suggest strategies to prevent plastic bag pollution reaching oceans. … … … … … … … … [4] (c) Fig. 1.2 shows the net primary productivity of different aquatic ecosystems. open ocean coastal waters lakes and streams estuaries 0 10 20 30 40 50 60 70 80 90 100 net primary productivity / arbitrary units Fig. 1.2 (i) Complete the bar chart in Fig. 1.2 to show a net primary productivity of 23 arbitrary units for lakes and streams. [1] (ii) Suggest why net primary productivity is low in open oceans. … … … … [2] (iii) An estuary is found where a river meets coastal waters. The net primary productivity of an estuary is high because there is a high concentration of nutrients. Suggest reasons why the concentration of nutrients is high. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) fish; 1 1(a)(ii) birds; 1 1(a)(iii) thrown / fallen from boats; thrown / lost by fishermen; blown from land; lost from landfill; carried by streams and rivers; 2 1(a)(iv) 26 / 26.1 / 26.09; 1 1(b)(i) (the) transfer / flow / movement of energy; 1 1(b)(ii) less food for top predators; numbers decrease; less feeding on seagrass; seagrass increases; less predation on squid / jellyfish; increased numbers of squid / jellyfish; long term effect – populations stabilise; 4 1(b)(iii) education; to use plastic bags more ecologically / about their effects on sea life; charging for bags at shops; to reduce use; change to paper bags; to reduce number of bags used; legislation to reduce single-use bags; to force consumers and shops to change habits; improved recycling / re-use; to prevent them getting in the sea; 4 Question Answer Marks 1(c)(i) correct plot + correct width + shading; 1 1(c)(ii) organic material sinks to bottom of ocean floor; sunlight cannot penetrate into ocean; so no photosynthesis; cold restricts enzymes / photosynthesis (RHS); 2 1(c)(iii) river flows from land to sea; collects nutrients as it crosses the land; named example; minerals from eroding rocks; excess fertilisers; sewage spilt into rivers / septic tanks leak / waste from cattle; tides mix seawater and freshwater; churning by tidal waters; 3

This question in 8291/21 Oct/Nov 2021

2 Fig. 2.1 shows a habitat changing over time from open water to mixed woodland. Key mixed woodland grasses and shrubs swampy ground open water sediment Fig. 2.1 (a) (i) State the process shown in Fig. 2.1. … [1] (ii) Explain the reasons for the changes shown in Fig. 2.1. … … … … … … … … … … … … [6] (iii) Explain what is meant by abiotic and biotic factors of an ecosystem. Give an example for each. abiotic … … … example … biotic … … … example … [4] (b) Table 2.1 compares subsistence farming with commercial farming. Table 2.1 factor subsistence farming commercial farming amount of produce sold low high destination of foods consumed on farm or locally high proportion processed by food manufacturers power source animals fossil fuel, electricity plant nutrition organic e.g. legumes, ash, chemical fertilisers bone, manure pest control crop rotation, intercropping commercial pesticides weed control rotations, hoeing, commercial herbicide hand picking seed from own crops from commercial grower livestock feed from own crops, fodder from commercial feed manufacturer (i) Explain how commercial farming described in Table 2.1 can lead to loss of local habitats. … … … … … … … … [4] (ii) Subsistence farmers often clear land for crops. Explain why clearing land leads to loss of biodiversity. … … … … … … [3] (iii) Describe a strategy to prevent land being cleared for crops. … … … … [2] [Total: 20]

20 marks

Mark scheme: 2(a)(i) succession; 1 2(a)(ii) sedimentation; (of) soil / minerals; dead / decaying leaves; build-up in the water; shallow water evaporates; due to temperature / wind; land begins to dry; plants colonise swampy area; soil fertility increases; shrubs and trees appear; plants attract herbivores; herbivores attract carnivores; 6 2(a)(iii) abiotic: non-living parts of the environment; valid example; biotic: living part of the environment; valid example; 4 Question Answer Marks 2(b)(i) large amounts of produce; requires large amount of land; transport / power; damages environment; overuse of fertilisers; causes eutrophication in aquatic environment; overuse of pesticides / herbicides; damage food webs / disrupt habitats; 4 2(b)(ii) deforestation / removal of plants; leads to loss of soil fertility / erosion; loss of food / shelter; causes loss of animals / emigration; disrupts food web; planting crops / monoculture reduces biodiversity; 3 2(b)(iii) education; encourage people to respect the environment; legislation; fines for deforestation; encourage ecotourism; to earn a living from the biodiversity; 2

This question in 8291/21 Oct/Nov 2021

1 (a) Fig. 1.1 shows information about water needed to produce cotton for clothing. Content removed due to copyright restrictions. Fig. 1.1 (i) Calculate the volume of water in litres used to make jeans for a class of 30 students. … litres [1] (ii) A volume of 75 000 litres of water is used to produce t-shirts for a class of students. Calculate the number of people for which this volume would provide drinking water for one year. … [2] (iii) Describe the impact of growing cotton on water stores and flows. Use information from Fig. 1.1 to support your answer. … … … … … … … … [4] (b) Fig. 1.2 shows the level of water stress in the top ten cotton producing countries. Water stress is when the demand for water exceeds supply. very high water high stress medium moderate low (#1) (#2) (#3) (#4) (#5) (#6) (#7) (#8) (#9) (#10) Greece India China USAPakistan BrazilUzbekistanAustralia TurkeyArgentina cotton producing countries in decreasing order Fig. 1.2 (i) Discuss what is shown by the data in Fig. 1.2. … … … … [3] (ii) Water use for China in 2019 was 598.1 billion m3. The total renewable water resources available in 2019 were 2840 billion m3. Calculate the water stress for China in 2019. Use the formula: water stress = (water use ÷ total renewable water resources available) × 100 … % [1] (c) Fig. 1.3 shows the reduction in size of the Aral Sea located in Uzbekistan and Kazakhstan. 1960 1971 1976 X X X 1989 2014 2020 X X X Key water seasonal lakes land Fig. 1.3 (i) Estimate the percentage loss in area for the Aral Sea between 1960 and 1989 shown in Fig. 1.3. … % [1] (ii) Suggest the impact of the loss of the Aral Sea on people living at location X shown in Fig. 1.3. … … … … [2] (iii) A new dam project is planned to divert water to help increase water levels in the Aral Sea. Suggest reasons why people may object to the construction of a dam. … … … … … … [3] (d) Growing cotton uses more pesticides than any other crop. Suggest the negative impacts of pesticide use. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) 240 000; 1 1(a)(ii) 75; 2500 / 2.5 = 1000; 75 000 / 1000; 2 1(a)(iii) large scale use of water; reduction in ground water stores; diversion of natural water flows; (groundwater depletion) leads to salt water intrusion / salinisation; land subsidence; 4 1(b)(i) most cotton producing countries have some water stress; no pattern to ranking and stress level; Uzbekistan has extremely high water stress; Brazil has the lowest water stress; cotton production is not the main cause of water stress ; 3 1(b)(ii) 21.059 / 21.06 / 21.1; 1 1(c)(i) any number between 20 and 35%; 1 1(c)(ii) loss of fishing industry; salinisation / desertification of soil; can’t grow crops; poverty related illness; migration away; 2 Question Answer Marks 1(c)(iii) cost; silting of river lower down / reduced flow; environmental damage during building; displacement of people; noise / visual pollution; loss of habitat; leads to loss of biodiversity; will flood some areas; 3 1(d) loss of insects; beneficial insects affected; biomagnification - increased concentration the higher the animal is in a food chain; bioaccumulation - accumulation of chemical in a particular species affects non-target species as alternative to loss of insects; harms other species; pollution risk to water stores / air; 3

This question in 8291/22 Oct/Nov 2021

2 (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 200temperature precipitation 22 / °C 150 / mm 20 100 18 16 50 14 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Key precipitation minimum temperature maximum temperature N Key remaining area of rainforest former rainforest port key settlement key road Indian airport Ocean palm plantation Madagascar Fig. 2.1 (i) The temperature range is the difference between the highest and lowest value. State the temperature range for March in Madagascar shown in Fig. 2.1. … °C [1] (ii) State the precipitation for February in Madagascar shown in Fig. 2.1. … mm [1] (iii) Describe the changes in the area of rainforest shown in Fig. 2.1. … … … … … … … … [4] (iv) Suggest reasons for the changes in the area of rainforest shown in Fig. 2.1. … … … … … … … … [4] (v) Explain how the climate of Madagascar affects the productivity of the remaining area of rainforest shown in Fig. 2.1. … … … … [2] (b) Soil quality has decreased in some parts of Madagascar. Explain the impacts of decreased soil quality on vegetation. … … … … … … … … [4] (c) Suggest strategies to sustainably manage rainforests in less economically developed countries (LEDCs). … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 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

This question in 8291/22 Oct/Nov 2021

1 (a) Table 1.1 shows the number of marine wildlife affected by marine debris in one year. Table 1.1 marine debris wildlife bottles cans lobster fishing fishing fishing plastic string other group and hooks lines nets bags and fish rope traps amphibians 1 0 0 0 3 1 6 0 1 birds 2 0 0 5 45 53 19 10 4 fish 5 1 2 1 48 11 11 7 3 invertebrates 6 2 1 1 14 12 6 13 0 mammals 0 0 0 3 6 1 6 6 1 reptiles 0 0 0 0 10 4 1 3 1 (i) State which wildlife group is affected by every type of marine debris shown in Table 1.1. … [1] (ii) State which wildlife group is most affected by marine debris shown in Table 1.1. … [1] (iii) Suggest two sources of the marine debris shown in Table 1.1. … … [2] (iv) Calculate the percentage of all mammals in Table 1.1 affected by plastic bags. … % [1] (b) Fig. 1.1 shows part of an ocean food web. killer whale tiger shark green sea turtle leatherback sea turtle squid jellyfish shrimp zooplankton sea grass phytoplankton Fig. 1.1 (i) State what the arrows in the food web shown in Fig. 1.1 represent. … … [1] (ii) Sea turtles are under threat because of plastic bag pollution in the sea. The turtles mistake the bags for jellyfish. Explain the effects of a reduction in sea turtle numbers on the food web shown in Fig. 1.1. … … … … … … … … [4] (iii) Suggest strategies to prevent plastic bag pollution reaching oceans. … … … … … … … … [4] (c) Fig. 1.2 shows the net primary productivity of different aquatic ecosystems. open ocean coastal waters lakes and streams estuaries 0 10 20 30 40 50 60 70 80 90 100 net primary productivity / arbitrary units Fig. 1.2 (i) Complete the bar chart in Fig. 1.2 to show a net primary productivity of 23 arbitrary units for lakes and streams. [1] (ii) Suggest why net primary productivity is low in open oceans. … … … … [2] (iii) An estuary is found where a river meets coastal waters. The net primary productivity of an estuary is high because there is a high concentration of nutrients. Suggest reasons why the concentration of nutrients is high. … … … … … … [3] [Total: 20]

20 marks

Mark scheme: 1(a)(i) fish; 1 1(a)(ii) birds; 1 1(a)(iii) thrown / fallen from boats; thrown / lost by fishermen; blown from land; lost from landfill; carried by streams and rivers; 2 1(a)(iv) 26 / 26.1 / 26.09; 1 1(b)(i) (the) transfer / flow / movement of energy; 1 1(b)(ii) less food for top predators; numbers decrease; less feeding on seagrass; seagrass increases; less predation on squid / jellyfish; increased numbers of squid / jellyfish; long term effect – populations stabilise; 4 1(b)(iii) education; to use plastic bags more ecologically / about their effects on sea life; charging for bags at shops; to reduce use; change to paper bags; to reduce number of bags used; legislation to reduce single-use bags; to force consumers and shops to change habits; improved recycling / re-use; to prevent them getting in the sea; 4 Question Answer Marks 1(c)(i) correct plot + correct width + shading; 1 1(c)(ii) organic material sinks to bottom of ocean floor; sunlight cannot penetrate into ocean; so no photosynthesis; cold restricts enzymes / photosynthesis (RHS); 2 1(c)(iii) river flows from land to sea; collects nutrients as it crosses the land; named example; minerals from eroding rocks; excess fertilisers; sewage spilt into rivers / septic tanks leak / waste from cattle; tides mix seawater and freshwater; churning by tidal waters; 3

This question in 8291/23 Oct/Nov 2021

2 Fig. 2.1 shows a habitat changing over time from open water to mixed woodland. Key mixed woodland grasses and shrubs swampy ground open water sediment Fig. 2.1 (a) (i) State the process shown in Fig. 2.1. … [1] (ii) Explain the reasons for the changes shown in Fig. 2.1. … … … … … … … … … … … … [6] (iii) Explain what is meant by abiotic and biotic factors of an ecosystem. Give an example for each. abiotic … … … example … biotic … … … example … [4] (b) Table 2.1 compares subsistence farming with commercial farming. Table 2.1 factor subsistence farming commercial farming amount of produce sold low high destination of foods consumed on farm or locally high proportion processed by food manufacturers power source animals fossil fuel, electricity plant nutrition organic e.g. legumes, ash, chemical fertilisers bone, manure pest control crop rotation, intercropping commercial pesticides weed control rotations, hoeing, commercial herbicide hand picking seed from own crops from commercial grower livestock feed from own crops, fodder from commercial feed manufacturer (i) Explain how commercial farming described in Table 2.1 can lead to loss of local habitats. … … … … … … … … [4] (ii) Subsistence farmers often clear land for crops. Explain why clearing land leads to loss of biodiversity. … … … … … … [3] (iii) Describe a strategy to prevent land being cleared for crops. … … … … [2] [Total: 20]

20 marks

Mark scheme: 2(a)(i) succession; 1 2(a)(ii) sedimentation; (of) soil / minerals; dead / decaying leaves; build-up in the water; shallow water evaporates; due to temperature / wind; land begins to dry; plants colonise swampy area; soil fertility increases; shrubs and trees appear; plants attract herbivores; herbivores attract carnivores; 6 2(a)(iii) abiotic: non-living parts of the environment; valid example; biotic: living part of the environment; valid example; 4 Question Answer Marks 2(b)(i) large amounts of produce; requires large amount of land; transport / power; damages environment; overuse of fertilisers; causes eutrophication in aquatic environment; overuse of pesticides / herbicides; damage food webs / disrupt habitats; 4 2(b)(ii) deforestation / removal of plants; leads to loss of soil fertility / erosion; loss of food / shelter; causes loss of animals / emigration; disrupts food web; planting crops / monoculture reduces biodiversity; 3 2(b)(iii) education; encourage people to respect the environment; legislation; fines for deforestation; encourage ecotourism; to earn a living from the biodiversity; 2

This question in 8291/23 Oct/Nov 2021

3 (a) Light pollution is caused by the use of artificial light. Light pollution has been linked to a rapid decrease in insect populations. (i) Suggest why the use of artificial light is increasing. … … [1] (ii) Suggest why a decrease in insect populations is of global concern. … … … … [2] (b) The corn earworm moth is a species of insect affected by light pollution. The moth will not reproduce if light levels are too high. Fig. 3.1 shows the corn earworm larva and Fig. 3.2 shows the corn earworm moth. Fig. 3.1 Fig. 3.2 The corn earworm larvae are a pest of corn, cotton, tomato and tobacco plants. A farmer uses a light trap to investigate the population of corn earworm moths in three fields, A, B and C. Each field is sampled for three weeks. The number of corn earworm moths collected each week for three weeks is recorded. The results are shown in Table 3.1. Table 3.1 field A field B field C week 1 16 7 250 number of corn week 2 17 3 235 earworm moths week 3 15 2 265 collected average 16 4 … (i) Complete Table 3.1 by calculating the mean (average) number of corn earworm moths collected in field C. [1] (ii) The farmer uses the data in Table 3.2 to decide whether to spray the fields with insecticide. Table 3.2 average weekly number of corn spray frequency earworm moths > 350 every 3 days 11–349 every 4 days 5–10 every 5 days < 5 no spray Use the data to suggest the spray frequency for fields A and B. field A … field B … [2] (iii) Describe two agricultural techniques that control crop pests, other than using insecticide. 1 … … 2 … … [2] (iv) The farmer selected the three fields out of 50 possible fields for this investigation. Describe a sampling strategy to select the three fields to ensure the investigation is free from bias. … … … … … … [3] (v) A sweep net is a way of collecting insects. Describe the benefits and limitations of using a sweep net to collect insects. benefits … … … … limitations … … … … [4] [Total: 15]

15 marks

Mark scheme: 3(a)(i) any one from: increased (human) population; (increased) urbanisation / electricity more accessible / (more) industrialised; decreased cost of lights; increase in wealth for some people / people can afford electricity / decrease cost of electricity; 3(a)(ii) any two or developed from: insects are pollinators; reduce food crops / less food for people; loss of biodiversity / disrupting food chain / food web; insects, are food for other animals / are decomposers; biological control; 2 3(b)(i) 250; 1 3(b)(ii) A: every 4 days; B: no spray; 2 Question Answer Marks 3(b)(iii) any two or developed from: pest resistant crops / GM crops; biological control; companion planting / planting sacrificial plants; mechanical control or named example picking pest by hand / nets / cages / pheromone traps; release sterile insects; 2 3(b)(iv) random (sampling); method described: each field given a number or letter / use a grid; three fields picked from a hat / number generator; 3 3(b)(v) max [4] total: max three benefits: (equipment is) inexpensive; easy to use / little training needed; lots of insects collected; insects not harmed / insects are alive; crops not harmed; max three limitations: does not work well in short or dense vegetation / doesn’t sample from within vegetation; net easily damaged; labour intensive / time consuming / non-automatic / a person has to do it; in-built bias / choose where to sweep; non-selective for type of insect; insects, escape / fall out / fly out / move away from net / doesn’t collect insects that attach firmly to vegetation; 4

This question in 8291/21 May/June 2022

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) (i) Suggest how the percentage forest cover for a country can be measured. … … [1] (ii) Explain how deforestation reduces biodiversity. … … … … [2] (b) A student used a questionnaire to ask some people in Ethiopia for their opinion on how forest cover has changed in their local area. Table 4.1 shows the results of the questionnaire. Table 4.1 percentage response rapidly gradually same as increasing no opinion decreasing decreasing before 50 30 10 7 3 (i) Write a suitable conclusion that summarises the main opinion on how forest cover has changed in Ethiopia. … … [1] (ii) Draw a pie chart of the data in Table 4.1. Complete the key. 0 Key … … … … … [3] (iii) Suggest one piece of additional information that is needed to ensure the data in Table 4.1 is reliable. … … [1] (c) In 2019, a major reforestation programme took place in Ethiopia. 350 million trees were planted over a 12-hour period in July. (i) Suggest one reason why not all of the 350 million trees planted will grow into mature trees. … … [1] (ii) Suggest one reason why other countries do not have a similar reforestation programme. … … [1] (iii) Explain how reforestation can improve water security in a region. … … … … … … [3] (iv) In the past, eucalyptus trees were used to reforest areas of Ethiopia. Eucalyptus trees are not native to Ethiopia. Suggest the negative impacts of planting non-native trees. … … … … … … [3] (v) Explain how reforestation can help manage climate change. … … … … … … … … [4] [Total: 20]

20 marks

Mark scheme: 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

This question in 8291/21 May/June 2022

4 (a) Table 4.1 shows data for total forest cover in Ethiopia from 1990 to 2010. Ethiopia is a country in Africa. Table 4.1 year total forest cover / 1000 ha 1990 15 114 2000 13 705 2005 13 000 2010 12 296 (i) Calculate the percentage change in total forest cover from 1990 to 2010. percentage change = … [2] (ii) Suggest reasons for the decrease in forest cover shown in Table 4.1. … … … … … … [3] (b) A student used a questionnaire to ask farmers in six areas, A to F, of Ethiopia about their opinion on planting trees in their local area. Table 4.2 shows the results of the questionnaire. Table 4.2 Are you in favour of planting more trees on your land? percentage response area number of respondents yes no don’t know A 120 82 15 3 B 100 83 17 0 C 60 93 7 0 D 120 89 10 1 E 5 80 20 0 F 120 94 4 2 average 12 1 total … (i) Complete Table 4.2 to determine the average total percentage responses for yes. [1] (ii) Write a suitable conclusion that summarises the main opinion of the farmers on planting more trees on their land. … … [1] (iii) Describe a sampling strategy to select the farmers to ensure the results of the questionnaire are free from bias. … … … … … … [3] (iv) Suggest limitations with the data in Table 4.2. … … … … [2] [Total: 12]

12 marks

Mark scheme: 4(a)(i) (M1  15114) 100 = (–) 18.6 / 19; 2 4(a)(ii) any three or developed from: increased population; more homes needed; more land needed for farming / to provide food; increased urbanisation; any one other use of land e.g. logging / timber / mining / change of land use; economic reason; forest / wild, fires; 3 4(b)(i) 87; 1 4(b)(ii) in favour (of planting more trees on their land); 1 4(b)(iii) random (sampling); method described: each farmer (in the area) given a number or letter or label; idea farmers picked from a hat / number generator; 3 4(b)(iv) any two from: area E has only 5 respondents / not representative; no information on how the farmers were selected; no information on demographic of farmer / age / gender; different number of farmers; small number of total farmers; no indication of how strongly they felt; size of farm / type of farm not given; 2

This question in 8291/22 May/June 2022

4 (a) Table 4.1 shows data for total forest cover in Ethiopia from 1990 to 2010. Ethiopia is a country in Africa. Table 4.1 year total forest cover / 1000 ha 1990 15 114 2000 13 705 2005 13 000 2010 12 296 (i) Calculate the percentage change in total forest cover from 1990 to 2010. percentage change = … [2] (ii) Suggest reasons for the decrease in forest cover shown in Table 4.1. … … … … … … [3] (b) A student used a questionnaire to ask farmers in six areas, A to F, of Ethiopia about their opinion on planting trees in their local area. Table 4.2 shows the results of the questionnaire. Table 4.2 Are you in favour of planting more trees on your land? percentage response area number of respondents yes no don’t know A 120 82 15 3 B 100 83 17 0 C 60 93 7 0 D 120 89 10 1 E 5 80 20 0 F 120 94 4 2 average 12 1 total … (i) Complete Table 4.2 to determine the average total percentage responses for yes. [1] (ii) Write a suitable conclusion that summarises the main opinion of the farmers on planting more trees on their land. … … [1] (iii) Describe a sampling strategy to select the farmers to ensure the results of the questionnaire are free from bias. … … … … … … [3] (iv) Suggest limitations with the data in Table 4.2. … … … … [2] [Total: 12]

12 marks

Mark scheme: 4(a)(i) (M1  15114) 100 = (–) 18.6 / 19; 2 4(a)(ii) any three or developed from: increased population; more homes needed; more land needed for farming / to provide food; increased urbanisation; any one other use of land e.g. logging / timber / mining / change of land use; economic reason; forest / wild, fires; 3 4(b)(i) 87; 1 4(b)(ii) in favour (of planting more trees on their land); 1 4(b)(iii) random (sampling); method described: each farmer (in the area) given a number or letter or label; idea farmers picked from a hat / number generator; 3 4(b)(iv) any two from: area E has only 5 respondents / not representative; no information on how the farmers were selected; no information on demographic of farmer / age / gender; different number of farmers; small number of total farmers; no indication of how strongly they felt; size of farm / type of farm not given; 2

This question in 8291/23 May/June 2022

2 (a) Fig. 2.1 shows a photograph of an area of densely forested land affected by human activity. Fig. 2.1 (i) Suggest reasons why there is a reduction in forest cover shown in Fig. 2.1. … … … … [2] (ii) Explain why forest fragmentation can lead to loss of biodiversity. … … … … … … [3] (b) Explain how trees absorb carbon dioxide from the atmosphere. … … … … … … [3] (c) Two types of tree, conifer and broadleaf, are considered for planting in a managed forest. The graph in Fig. 2.2 shows predicted data for the quantity of carbon stored by the two types of tree in a 50-hectare forest. The quantity of carbon stored is measured in carbon dioxide equivalent tonnes, tCO2e. 25 000 20 000 15 000 total carbon stored 10 000 / tCO2e 5 000 0 –5 000 2020 2025 2030 2035 2040 2045 2050 year Key conifer broadleaf Fig. 2.2 (i) Use Fig. 2.2 to calculate the percentage increase in quantity of carbon stored from 2020 to 2050 for conifer trees. percentage = … [2] (ii) Recommend which type of tree, conifer or broadleaf, should be planted in the managed forest. Give a reason for your answer. … … [1] (d) Table 2.1 shows historical data for forest areas planted in eight countries in 2015. Table 2.1 forest area country / million ha Brazil 8 China 79 India 12 Japan 10 Russia 20 Sweden 14 UK 3 USA 26 (i) Plot the data as a bar chart. [4] (ii) Suggest why some countries plant more trees than other countries. … … [1] [Total: 16]

16 marks

Mark scheme: 2(a)(i) any two from: 2 wood used for fuel / timber / export; increased human population; land cleared for: agriculture / mineral extraction / hydroelectric or reservoir projects / homes / buildings / roads; fire break; habitat loss; AVP; 2(a)(ii) any three from: 3 habitat loss; alters growing conditions, e.g. temperature / moisture / light / wind; increases isolation / separation between forest communities; movement of plants and animals is inhibited / some will migrate; trees are producers so less energy enters food chains; restricts breeding / gene flow; increase in invasive plants; 2(b) any three from: 3 by photosynthesis; chlorophyll (in leaves) / in chloroplasts; captures light energy / uses sunlight; carbon dioxide + water → oxygen + glucose OR 6CO2 + 6H2O → C6H12O6 + 6O2 ; 2(c)(i) M1 – 1000 − 23 000 OR 24 000; 2 ((M1  1000)  100 =) 2400; 2(c)(ii) any one from: 1 conifer AND absorbs / stores more carbon (dioxide); conifer AND grows all year round; 2(d)(i) suitable linear scale; 4 axis labels AND units; bars not touching AND of equal width; correct plotting of bars; 2(d)(ii) more land space / lower population density / more concerned about climate change / wealth / more suitable conditions / AVP; 1 grow trees for food;

This question in 8291/21 Oct/Nov 2022

3 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 energy resource. (i) State one non-renewable energy resource, other than coal. … [1] (ii) Explain why fossil fuel depletion can lead to energy insecurity. … … … … [2] (iii) Rationing fossil fuels is a strategy to manage energy insecurity. Outline one advantage and one disadvantage of this strategy. advantage … … disadvantage … … [2] (b) The location of the coal mine was the only known habitat of a species of snail, the Mount Augustus snail. Fig. 3.2 is a drawing of a Mount Augustus snail. 90 mm Fig. 3.2 Before mining started, the mining company was required to move Mount Augustus snails from the area of the planned coal mine. This took two years. 4000 snails were moved to locations nearby. The population of the snails was monitored using a capture-mark-recapture method. Pitfall traps were used to collect the snails. (i) Describe a capture-mark-recapture method to estimate the population of the Mount Augustus snails using a pitfall trap. … … … … … … … … … … … … [5] (ii) Assumptions are made when using capture-mark-recapture methods of estimating populations. One assumption is that during the survey period there are no deaths or births within the population surveyed. State two other assumptions. … … … … [2] (c) The results of a snail capture-mark-recapture survey are shown in Table 3.1. Table 3.1 number of snails numbers of marked number of marked estimate ofrecapture in first sample, and unmarked snails snails in second population size, date n1 in second sample, n2 sample, m2 N July 2010 148 160 6 3947 July 2011 151 135 5 … July 2012 130 145 5 3770 July 2013 142 152 6 3597 July 2014 133 147 8 2444 July 2015 75 60 2 2250 The Lincoln index is used to estimate population size using the formula shown. n1 × n2 N = m2 (i) Complete Table 3.1 by calculating the estimated population size, N, for July 2011. [1] (ii) Use Table 3.1 to write a suitable conclusion about the population of snails. … … [1] (iii) 50 snails were tagged with a radio tracking device to record their location after they were released back into the wild. After 18 months, 30% of the snails had died. Calculate the number of snails that were alive after 18 months. … [2] (iv) 2000 Mount Augustus snails were not released back into the wild. These snails were kept in captivity. Suggest reasons why. … … … … [2] (d) A food chain for the Mount Augustus snail is shown. grass earthworm Mount Augustus snail rat (i) Identify the primary consumer in this food chain. … [1] (ii) Rats can spread diseases. Poison is used to control rats. Suggest the disadvantage of using poison to control rats. … … [1] (e) A scientist wanted to investigate the best diet to feed the Mount Augustus snails kept in captivity. The scientist used this method: • select 10 snails • label the snails 1 to 10 • record the mass of each snail at the start • feed five snails diet A for 10 weeks • diet A – earthworms • feed five different snails diet B for 10 weeks • diet B – earthworms and calcium • record the mass of each snail after 10 weeks. Table 3.2 shows the results. Table 3.2 diet A diet B mass of snail change in mass of snail change in snail mass snail mass after 10 after 10 / g / g at start at start weeks weeks / g / g / g / g 1 80 80 0 6 75 79 +4 2 81 82 +1 7 72 80 +8 3 93 91 8 87 95 +8 … 4 73 75 +2 9 93 97 +6 5 79 55 -24 10 85 92 +7 (i) Complete Table 3.2 for snail 3, diet A. [2] (ii) Calculate the average change in mass for diet B. … g [1] (iii) Suggest a reason for the result for snail 5, diet A. … … [1] (iv) Use Table 3.2 to write a conclusion for the investigation. Give a reason for your conclusion. … … [1] [Total: 25]

25 marks

Mark scheme: 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

This question in 8291/21 Oct/Nov 2022

2 (a) The photograph in Fig. 2.1 shows an area of forested land that has been cleared. Fig. 2.1 (i) Suggest reasons for the land clearance in Fig. 2.1. … … … … [2] (ii) Some trees have been replanted in this area. Many of the trees are non-native species. Explain the impacts of introducing non-native plant species to an area. … … … … … [3] (b) The bar chart in Fig. 2.2 shows the global loss in tropical tree cover from 2002 to 2018. loss in tropical tree cover / million ha 18 16 14 12 10 8 6 4 2 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 year Fig. 2.2 (i) State what the data in Fig. 2.2 indicates about the area of land covered by tropical forest from 2002 to 2016. … … [1] (ii) Use Fig. 2.2 to calculate the percentage change in the global loss in tropical tree cover from 2017 to 2018. percentage change = … [2] (iii) Suggest a reason for the percentage change from 2017 to 2018. … … [1] (c) Explain the benefits of afforestation. … … … … … … … … [4] (d) Table 2.2 shows data for the number of wild fires in one area of the Amazon rainforest from 2013 to 2019. Table 2.2 year 2013 2014 2015 2016 2017 2018 2019 number of wild fires 3800 9350 8750 8700 10 900 4050 10 750 (i) Plot the data as a bar chart. [4] (ii) Use Table 2.2 to calculate the average number of wild fires from 2013 to 2019 in this area of the Amazon rainforest. Give your answer to the nearest whole number. … [2] (iii) Fig. 2.3 shows the distribution of actively burning wild fires on one day in February 2020. N Tropic of Cancer Equator Tropic of Capricorn key wild fire Fig. 2.3 Describe the distribution of actively burning wild fires in Fig. 2.3. … … … … … … [3] (iv) Suggest reasons why the number of global wild fires is increasing. … … … … … … [3] [Total: 25]

25 marks

Mark scheme: 2(a)(i) any two from: 2 wood used for fuel / timber / export; increased human population; land cleared for agriculture / mineral extraction / hydroelectric or reservoir projects / homes / buildings / roads; 2(a)(ii) any three from: 3 can become invasive; outcompetes / competition with other plants; example given, e.g. grows taller; so receives more sunlight; may not be edible to animals / contains toxins / toxic to animals; leads to loss of biodiversity; disrupts food web / chains; 2(b)(i) less or decreasing tropical forest / more tropical forest being destroyed; 1 2(b)(ii) M1 15.8 – 12 / 3.8; 2 (M1  15.8  100) 24.051 / 24.05 / 24.1 / 24; or M1 15.9 – 12 / 3.9; (M1  15.9  100) 24.528 / 24.53 / 24.5 / 25; 2(b)(iii) any one from: 1 increased awareness of importance of trees; international pressure; reforestation / afforestation initiatives; 2(c) any four from: 4 CO2 removal; by photosynthesis; by growing trees; CO2 storage; by mature trees; reduction in global warming / climate change; reference to water cycle, e.g. increases interception, increases infiltration, decreases run-off; idea that young forests remove more CO2 than existing or mature forests; tree (roots) improve soil (structure); reduces changes of mass movement / landslides; reduces soil erosion; increases biodiversity / provides habitat; 2(d)(i) suitable linear scale; 4 axis labels and units; bars of equal width and not touching; correct plotting / correct height of bars; 2(d)(ii) 8042.857; 2 8043 (answer given to nearest whole number); 2(d)(iii) any three from: 3 southern Africa; south of equator / along tropic of Capricorn; north of tropic of Cancer; coastal Australia; 2(d)(iv) any three from: 3 climate change / enhanced greenhouse effect; leads to extreme weather / high temperatures; leads to drought; increased lightning (strikes); controlled fires getting out of control;

This question in 8291/22 Oct/Nov 2022

2 (a) Fig. 2.1 shows a photograph of an area of densely forested land affected by human activity. Fig. 2.1 (i) Suggest reasons why there is a reduction in forest cover shown in Fig. 2.1. … … … … [2] (ii) Explain why forest fragmentation can lead to loss of biodiversity. … … … … … … [3] (b) Explain how trees absorb carbon dioxide from the atmosphere. … … … … … … [3] (c) Two types of tree, conifer and broadleaf, are considered for planting in a managed forest. The graph in Fig. 2.2 shows predicted data for the quantity of carbon stored by the two types of tree in a 50-hectare forest. The quantity of carbon stored is measured in carbon dioxide equivalent tonnes, tCO2e. 25 000 20 000 15 000 total carbon stored 10 000 / tCO2e 5 000 0 –5 000 2020 2025 2030 2035 2040 2045 2050 year Key conifer broadleaf Fig. 2.2 (i) Use Fig. 2.2 to calculate the percentage increase in quantity of carbon stored from 2020 to 2050 for conifer trees. percentage = … [2] (ii) Recommend which type of tree, conifer or broadleaf, should be planted in the managed forest. Give a reason for your answer. … … [1] (d) Table 2.1 shows historical data for forest areas planted in eight countries in 2015. Table 2.1 forest area country / million ha Brazil 8 China 79 India 12 Japan 10 Russia 20 Sweden 14 UK 3 USA 26 (i) Plot the data as a bar chart. [4] (ii) Suggest why some countries plant more trees than other countries. … … [1] [Total: 16]

16 marks

Mark scheme: 2(a)(i) any two from: 2 wood used for fuel / timber / export; increased human population; land cleared for: agriculture / mineral extraction / hydroelectric or reservoir projects / homes / buildings / roads; fire break; habitat loss; AVP; 2(a)(ii) any three from: 3 habitat loss; alters growing conditions, e.g. temperature / moisture / light / wind; increases isolation / separation between forest communities; movement of plants and animals is inhibited / some will migrate; trees are producers so less energy enters food chains; restricts breeding / gene flow; increase in invasive plants; 2(b) any three from: 3 by photosynthesis; chlorophyll (in leaves) / in chloroplasts; captures light energy / uses sunlight; carbon dioxide + water → oxygen + glucose OR 6CO2 + 6H2O → C6H12O6 + 6O2 ; 2(c)(i) M1 – 1000 − 23 000 OR 24 000; 2 ((M1  1000)  100 =) 2400; 2(c)(ii) any one from: 1 conifer AND absorbs / stores more carbon (dioxide); conifer AND grows all year round; 2(d)(i) suitable linear scale; 4 axis labels AND units; bars not touching AND of equal width; correct plotting of bars; 2(d)(ii) more land space / lower population density / more concerned about climate change / wealth / more suitable conditions / AVP; 1 grow trees for food;

This question in 8291/23 Oct/Nov 2022

3 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 energy resource. (i) State one non-renewable energy resource, other than coal. … [1] (ii) Explain why fossil fuel depletion can lead to energy insecurity. … … … … [2] (iii) Rationing fossil fuels is a strategy to manage energy insecurity. Outline one advantage and one disadvantage of this strategy. advantage … … disadvantage … … [2] (b) The location of the coal mine was the only known habitat of a species of snail, the Mount Augustus snail. Fig. 3.2 is a drawing of a Mount Augustus snail. 90 mm Fig. 3.2 Before mining started, the mining company was required to move Mount Augustus snails from the area of the planned coal mine. This took two years. 4000 snails were moved to locations nearby. The population of the snails was monitored using a capture-mark-recapture method. Pitfall traps were used to collect the snails. (i) Describe a capture-mark-recapture method to estimate the population of the Mount Augustus snails using a pitfall trap. … … … … … … … … … … … … [5] (ii) Assumptions are made when using capture-mark-recapture methods of estimating populations. One assumption is that during the survey period there are no deaths or births within the population surveyed. State two other assumptions. … … … … [2] (c) The results of a snail capture-mark-recapture survey are shown in Table 3.1. Table 3.1 number of snails numbers of marked number of marked estimate ofrecapture in first sample, and unmarked snails snails in second population size, date n1 in second sample, n2 sample, m2 N July 2010 148 160 6 3947 July 2011 151 135 5 … July 2012 130 145 5 3770 July 2013 142 152 6 3597 July 2014 133 147 8 2444 July 2015 75 60 2 2250 The Lincoln index is used to estimate population size using the formula shown. n1 × n2 N = m2 (i) Complete Table 3.1 by calculating the estimated population size, N, for July 2011. [1] (ii) Use Table 3.1 to write a suitable conclusion about the population of snails. … … [1] (iii) 50 snails were tagged with a radio tracking device to record their location after they were released back into the wild. After 18 months, 30% of the snails had died. Calculate the number of snails that were alive after 18 months. … [2] (iv) 2000 Mount Augustus snails were not released back into the wild. These snails were kept in captivity. Suggest reasons why. … … … … [2] (d) A food chain for the Mount Augustus snail is shown. grass earthworm Mount Augustus snail rat (i) Identify the primary consumer in this food chain. … [1] (ii) Rats can spread diseases. Poison is used to control rats. Suggest the disadvantage of using poison to control rats. … … [1] (e) A scientist wanted to investigate the best diet to feed the Mount Augustus snails kept in captivity. The scientist used this method: • select 10 snails • label the snails 1 to 10 • record the mass of each snail at the start • feed five snails diet A for 10 weeks • diet A – earthworms • feed five different snails diet B for 10 weeks • diet B – earthworms and calcium • record the mass of each snail after 10 weeks. Table 3.2 shows the results. Table 3.2 diet A diet B mass of snail change in mass of snail change in snail mass snail mass after 10 after 10 / g / g at start at start weeks weeks / g / g / g / g 1 80 80 0 6 75 79 +4 2 81 82 +1 7 72 80 +8 3 93 91 8 87 95 +8 … 4 73 75 +2 9 93 97 +6 5 79 55 -24 10 85 92 +7 (i) Complete Table 3.2 for snail 3, diet A. [2] (ii) Calculate the average change in mass for diet B. … g [1] (iii) Suggest a reason for the result for snail 5, diet A. … … [1] (iv) Use Table 3.2 to write a conclusion for the investigation. Give a reason for your conclusion. … … [1] [Total: 25]

25 marks

Mark scheme: 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

This question in 8291/23 Oct/Nov 2022

3 (a) Brazil’s Atlantic forest contains approximately 6000 plant species, 263 amphibian species and 160 species of mammal, which are found nowhere else in the world. Rio de Janeiro and São Paulo are two of the world’s largest cities. These two cities are within the Atlantic forest. (i) The bar chart in Fig. 3.1 shows the area of Atlantic forest that is lost each year. 120 000 100 000 80 000 area of forest 60 000 lost / ha 40 000 20 000 0 1985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018 year Fig. 3.1 Complete Fig. 3.1 by plotting the data in Table 3.1. Table 3.1 year area of forest lost / ha 1990 100 000 2016 28 000 [2] (ii) State the two consecutive years which had the greatest difference in the area of forest lost. between … and … [1] (iii) Suggest reasons for the loss of Brazil’s Atlantic forest. … … … … … … [3] (b) In 2010, the USA and Brazil signed a 5-year debt for nature swap worth $21 million. Explain how a debt for nature swap can protect Brazil’s Atlantic forest. … … … … … … [3] (c) The local government use a questionnaire to find out if local people have benefited from the debt for nature swap. (i) The method used to select the people was: • select one street in São Paulo at random • select every female aged between 20 and 30 in each house on the street. Describe the limitations of this selection method. … … … … … … [3] (ii) One of the questions on the questionnaire is shown. response question yes no Did you benefit from the debt for nature swap? Describe one reason why yes / no response questions are used in a questionnaire. … … [1] [Total: 13]

13 marks

Mark scheme: 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

This question in 8291/21 May/June 2023

2 (a) In 2022, 80% of the timber used in the UK was imported. (i) Suggest one negative impact for the UK of importing timber. … [1] (ii) Financial incentives were offered to UK farmers to grow trees on agricultural land. Suggest two negative impacts of growing trees on agricultural land. 1 … … 2 … … [2] (b) Explain how growing more trees reduces the impact of carbon dioxide in the atmosphere. … … … … [2] (c) The photograph in Fig. 2.1 shows a forest, a road and a lake. Fig. 2.1 Describe how the photograph in Fig. 2.1 shows evidence of fragmentation. … … … … … … [3] (d) Pollinating insects enable trees to reproduce. Fig. 2.2 shows the broken-belted bumblebee, which is a pollinating insect. Fig. 2.2 The map in Fig. 2.3 shows the distribution of broken-belted bumblebees in part of the UK. Key N population of broken-belted bumblebee Scotland England Wales (i) Describe the distribution of broken-belted bumblebees shown in Fig. 2.3. … … … … [2] (ii) The data for the distribution map in Fig. 2.3 was collected using a survey. People completed an online survey for any species of bumblebee they observed. Fig. 2.4 shows the form used to collect the data. species: when you saw it: where you saw it: map grid reference: contact information: Fig. 2.4 Suggest the limitations of this type of bee population distribution survey. … … … … … … [3] (e) A scientist investigates the population of broken-belted bumblebees using a transect method. The transect is a measured straight line where the population of broken-belted bumblebees are located. The length of this transect line is 10 m. Describe how the scientist can use this transect line to estimate the population of broken- belted bumblebees. … … … … … … … … [4] (f) The diagram in Fig. 2.5 shows a natural bee nest in a tree. Fig. 2.5 Fig. 2.6 shows two types of artificial bee nest: a sun hive and a wooden hive. sun hive wooden hive Fig. 2.6 Suggest the benefits and limitations of the two artificial bee nests. … … … … … … … … … … [5] (g) The Asian hornet is an invasive species to the UK. Explain how the Asian hornet can endanger bumblebee populations in the UK. … … … … … … [3] [Total: 25]

25 marks

Mark scheme: 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

This question in 8291/21 May/June 2024

2 (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 rings form when trees grow more rapidly. The scientists make this hypothesis: ‘Emissions from a factory have a negative impact on tree growth in the local area.’ Fig. 2.1 shows tree ring data for one species of tree over an 80‑year period in the local area. The factory was opened at the start of the 80‑year period. tree ring width average tree ring width 0 20 40 60 80 year Fig. 2.1 The horizontal line represents the average tree ring width for this species of tree. Values above the horizontal line indicate higher than average tree ring width. (i) Discuss whether the data in Fig. 2.1 supports the scientists’ hypothesis. … … … … … … [3] (ii) Tree ring data is also used to reconstruct past climate conditions. State two other methods for reconstructing past climate conditions. 1 … 2 … [2] (b) A scientist uses a computer model to predict the effect of ground level ozone on plant growth over a 3‑year period. The model: • uses two concentrations of ozone, 20 and 120 parts per million (ppm) • predicts the mass of the plant stem every month for 3 years. Fig. 2.2 shows the results of the model. Key ozone concentration 20 ppm 120 ppm 280 270 260 250mass of plant stem / g 240 230 220 210 0 0.5 1.0 1.5 2.0 2.5 3.0 year Fig. 2.2 (i) Describe the results of the model shown in Fig. 2.2. … … … … [2] (ii) Another scientist wants to repeat the computer model. Suggest three pieces of additional information needed for the model to be repeated. 1 … 2 … 3 … [3] (c) Ground level ozone can form photochemical smog. (i) State the layer of the atmosphere which contains ground level ozone. … [1] (ii) Describe the formation of photochemical smog. … … … … … … [3] (iii) State two impacts of photochemical smog on human health. 1 … 2 … [2] (d) Table 2.1 shows the concentration of ground level ozone in ppm for a 24‑hour period in a USA city. Table 2.1 time ozone concentration / hour / ppm 0 0.10 3 0.10 6 0.30 9 0.34 12 0.62 15 0.92 18 0.84 21 0.18 24 0.10 (i) Plot the data as a line graph on the grid. Join each point with a straight line. [5] (ii) Calculate the range for ground level ozone concentration in the 24‑hour period. range = … ppm [1] (iii) A student concludes that the maximum ozone concentration in the 24‑hour period is 0.92 ppm. State whether the student’s conclusion is sensible. Justify your answer. … … [1] [Total: 23]

23 marks

Mark scheme: 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

This question in 8291/22 May/June 2024

2 (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 rings form when trees grow more rapidly. The scientists make this hypothesis: ‘Emissions from a factory have a negative impact on tree growth in the local area.’ Fig. 2.1 shows tree ring data for one species of tree over an 80‑year period in the local area. The factory was opened at the start of the 80‑year period. tree ring width average tree ring width 0 20 40 60 80 year Fig. 2.1 The horizontal line represents the average tree ring width for this species of tree. Values above the horizontal line indicate higher than average tree ring width. (i) Discuss whether the data in Fig. 2.1 supports the scientists’ hypothesis. … … … … … … [3] (ii) Tree ring data is also used to reconstruct past climate conditions. State two other methods for reconstructing past climate conditions. 1 … 2 … [2] (b) A scientist uses a computer model to predict the effect of ground level ozone on plant growth over a 3‑year period. The model: • uses two concentrations of ozone, 20 and 120 parts per million (ppm) • predicts the mass of the plant stem every month for 3 years. Fig. 2.2 shows the results of the model. Key ozone concentration 20 ppm 120 ppm 280 270 260 250mass of plant stem / g 240 230 220 210 0 0.5 1.0 1.5 2.0 2.5 3.0 year Fig. 2.2 (i) Describe the results of the model shown in Fig. 2.2. … … … … [2] (ii) Another scientist wants to repeat the computer model. Suggest three pieces of additional information needed for the model to be repeated. 1 … 2 … 3 … [3] (c) Ground level ozone can form photochemical smog. (i) State the layer of the atmosphere which contains ground level ozone. … [1] (ii) Describe the formation of photochemical smog. … … … … … … [3] (iii) State two impacts of photochemical smog on human health. 1 … 2 … [2] (d) Table 2.1 shows the concentration of ground level ozone in ppm for a 24‑hour period in a USA city. Table 2.1 time ozone concentration / hour / ppm 0 0.10 3 0.10 6 0.30 9 0.34 12 0.62 15 0.92 18 0.84 21 0.18 24 0.10 (i) Plot the data as a line graph on the grid. Join each point with a straight line. [5] (ii) Calculate the range for ground level ozone concentration in the 24‑hour period. range = … ppm [1] (iii) A student concludes that the maximum ozone concentration in the 24‑hour period is 0.92 ppm. State whether the student’s conclusion is sensible. Justify your answer. … … [1] [Total: 23]

23 marks

Mark scheme: 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

This question in 8291/23 May/June 2024

3 (a) A farmer investigates insect pests on soybean plants. Fig. 3.1 shows soybean plants. Fig. 3.1 The farmer investigates an area of soybean plants that is 7 rows by 7 columns. There is a total of 49 soybean plants. Fig. 3.2 shows the results from a random number generator. The farmer uses these results to select a sample of 6 soybean plants. Each number represents a row number and a column number. 56 71 29 56 33 22 32 60 53 28 23 72 13 Fig. 3.2 The farmer starts at number ‘56’. ‘56’ represents row 5 and column 6. The farmer circles this plant on Fig. 3.3. The farmer ignores a number in Fig. 3.2 if: • any part of the number is greater than 6 • a number is repeated. Fig. 3.3 shows the area of soybean plants the farmer investigates. column number 0 1 2 3 4 5 6 0 1 2 row 3 number 4 5 6 Fig. 3.3 (i) The farmer samples a total of 6 plants. The first 3 soybean plants selected from the random number generator are circled. Complete Fig. 3.3 by circling the 3 other soybean plants the farmer samples. [1] (ii) State one benefit of using a random number generator to select the soybean plants. … … [1] (b) The farmer uses a beating tray to investigate insect population. (i) Describe a beating tray method the student can use to estimate the total number of insects on the 49 soybean plants. … … … … … … … … … … [5] (ii) Describe two limitations of using a beating tray for investigating the insect population on soybean plants. 1 … … 2 … … [2] (c) The farmer concludes that the soybean plants are infested with aphids. Aphids are insects that eat soybean plants and reduce crop yield. The farmer introduces the harlequin beetle to the soybean plants. The harlequin beetle is a flying insect and is a predator of the aphids. Fig. 3.4 shows a harlequin beetle. 7 mm Fig. 3.4 The farmer records the population of aphids in 2 different fields. Fig. 3.5 shows the results. Key field 1: no predator field 2: predator added 300 250 200 mean number of aphids 150per leaf predator added to field 2 100 50 00 5 10 15 20 25 30 35 40 45 50 55 60 65 day Fig. 3.5 (i) Name the type of method for controlling the aphid population using a predator. … [1] (ii) Suggest why the predator was not added to field 1. … [1] (iii) Suggest why the aphid population was measured before the predator was added to field 2. … … [1] (iv) Write a conclusion using the data in Fig. 3.5. … … … … … … [3] (v) Suggest why the farmer covers the soybean plants with nets after the predator is added. … … … … [2] (d) The harlequin beetle was introduced to North America and Europe to control aphid populations. The harlequin beetle is now considered to be one of the world’s most invasive species. The harlequin beetle becomes inactive when temperatures are lower than 10 °C. Suggest why climate change could benefit the harlequin beetle. … … [1] (e) Increasing crop productivity by reducing pests is a strategy for managing food security. Hydroponics can also improve food security. (i) Explain how hydroponics improves food security. … … … … … … … … [4] (ii) Describe the limitations of large-scale food stockpiling as a method of reducing food insecurity. … … … … … … [3] (iii) Outline the impacts of food insecurity. … … … … … … … … [4] [Total: 29]

29 marks

Mark scheme: 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;

This question in 8291/21 Oct/Nov 2024

1 Fig. 1.1 shows a vertical aquaculture farm. Content removed due to copyright restrictions. Fig. 1.1 In Fig. 1.1, seaweed grows from ropes under the water. Shellfish such as mussels grow on chains. Scallops and oysters are farmed in nets and cages. Seaweed photosynthesises. Some species of seaweed grow up to 0.5 m in one day. The seaweed is harvested for use as human and animal food, organic fertiliser and biofuel; it is also used as an ingredient in natural medicines, cosmetics and bioplastics. Any seaweed that is not harvested falls to the sea floor and is covered by layers of sediment. (a) Vertical aquaculture farming is an example of adaptation to climate change. (i) Suggest why some crop farmers need to adapt to climate change by investing in aquaculture. … … … … … … [3] (ii) Suggest how vertical aquaculture can reduce the concentration of carbon dioxide in the atmosphere. … … … … … … [3] (iii) Suggest one benefit of vertical aquaculture farming other than reducing the impacts of climate change. … [1] (b) Fig. 1.2 shows the annual yield of seaweed from aquaculture farms in China from 1978 to 2014. 2.0 1.5 annual yield of 1.0 seaweed / million tonnes 0.5 0 1975 1985 1995 2005 2015 year Fig. 1.2 (i) Describe the trend in the annual yield of seaweed from aquaculture farms in China from 1978 to 2014. … … … … … … [3] (ii) Suggest one reason for a decrease in annual yield of seaweed from aquaculture farms. … … [1] (c) The seaweed aquaculture farming sector is predicted to grow. Fig. 1.3 shows three predictions for global yield of seaweed from aquaculture farms based on three different percentage growth rates. Key percentage growth rate per year 6% 12% 20% 12 000 10 000 annual 8000 yield of seaweed 6000 / million tonnes 4000 2000 0 2020 2025 2030 2035 2040 2045 2050 year Fig. 1.3 Table 1.1 shows the area of ocean required by 2050 for each percentage growth rate. Table 1.1 percentage growth rate area of ocean required by 2050 per year / km2 6 12 797 12 74 524 20 677 832 Suggest why there is concern about the impact of a 20% growth rate in global aquaculture. … … … … [2] (d) Overfishing impacts ecosystems. Describe strategies for reducing the impact of overfishing. … … … … … … [3] (e) The ocean is a source of salt water. (i) State three sources of surface fresh water. 1 … 2 … 3 … [3] (ii) The atmosphere contains water vapour. State three other gases in unpolluted air. 1 … 2 … 3 … [3] (f) Water is an abiotic component of an ecosystem. State three other abiotic components of an ecosystem. 1 … 2 … 3 … [3] [Total: 25]

25 marks

Mark scheme: Question Answer Marks 1(a)(i) any three from: 3 increasing global temperatures / global warming; extreme or severe weather; examples of extreme weather, e.g. drought / flooding / hurricanes; rising sea levels; (leading to) loss of land (for crops or agriculture); non-optimum conditions for crop growth (due to climate change); crop failure / reduced crop yield / less food; 1(a)(ii) any three from: 3 seaweed act as carbon sinks / stores / shellfish act as carbon sinks / stores; seaweed absorbs or uses carbon dioxide during photosynthesis; seaweed is fast growing so large volumes of carbon dioxide removed; provide an alternate food source other than meat based diet; (acts as raw ingredient in many products so) reduces need to extract other raw ingredients; (biofuels) reduce need for fossil fuels; 1(a)(iii) any one from: 1 habitat for marine wildlife; storm-surge protection; improved food security; high (aquatic) crop density or yield; 1(b)(i) any three from: 3 overall increase; 1978 to (1987–)1990 no change or little change / stable; decrease (2005–)2006 to 2007; relevant quoted data trend; 1(b)(ii) any one from: 1 extreme weather or description, e.g. storms / hurricanes; disease; unfavourable growing conditions or description; outcompeted by other species; competition from other ocean activities / industries; 1(c) any two from: 2 large area of ocean needed; limits (other) activities that can take place in ocean; competition with fishing / traditional marine harvesting; concern over impact on native species; increase in pollution (from boats); 1(d) any three from or developed: 3 legislation / international agreement; sustainable harvesting; protected areas; stated fisheries regulation: quotas / catch limits / closed seasons; changes to net size (protects juveniles) / changes to fishing method such as pole and line (reduces bycatch); 1(e)(i) any three from: 3 ice sheets; glaciers; lakes; rivers / streams; swamps; marshes; permafrost; 1(e)(ii) any three from: 3 nitrogen; oxygen; carbon dioxide; argon / noble gases; 1(f) any three from: 3 temperature; humidity; oxygen; carbon dioxide; salinity; (sun)light; pH;

This question in 8291/22 Oct/Nov 2024

3 Gold is a valuable metal. (a) Mercury, Hg, is used to extract gold in small-scale gold mining. Mercury is mixed with gold-containing minerals. The gold dissolves in mercury. The mercury-gold mixture is then heated. The mercury is converted into a gas and the gold is left to cool and become solid. Fig. 3.1 shows how gaseous mercury is deposited onto the land. Key Hg dust and gases Hg water Hg leaf Hg mercury movement of mercury (Hg) Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg gold Hg Fig. 3.1 Use Fig. 3.1 to explain how mercury is deposited onto the land. … … … … … … … … [4] (b) A chemist analyses soil samples from villages close to small-scale gold mines in five countries. Table 3.1 shows the results. Table 3.1 mercury concentration country / μg per g* China 4.5 Ghana 5.0 Peru 44.0 Tanzania 9.0 Venezuela 27.0 * μg of mercury per g of soil Plot the data as a bar chart on the grid. [4] (c) Many gold reserves are buried under areas of tropical rainforest. Fig. 3.2 shows an illegal gold mine in the Amazon rainforest. Fig. 3.2 Describe the impact of gold mining on the rainforest in Fig. 3.2. … … … … … … … … [4] (d) The polluter pays principle is a strategy for managing the impacts of pollution. (i) Describe how the polluter pays principle could manage the impacts of gold mining. … … … … [2] (ii) State two limitations of this principle for dealing with the impacts shown in Fig. 3.2. 1 … … 2 … … [2] (e) Sustainable management of resources is an environmental management strategy. (i) Define the term sustainability. … … … … [2] (ii) Suggest two strategies for managing gold as a resource. 1 … … 2 … … [2] [Total: 20]

20 marks

Mark scheme: 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;

This question in 8291/22 Oct/Nov 2024

3 (a) A farmer investigates insect pests on soybean plants. Fig. 3.1 shows soybean plants. Fig. 3.1 The farmer investigates an area of soybean plants that is 7 rows by 7 columns. There is a total of 49 soybean plants. Fig. 3.2 shows the results from a random number generator. The farmer uses these results to select a sample of 6 soybean plants. Each number represents a row number and a column number. 56 71 29 56 33 22 32 60 53 28 23 72 13 Fig. 3.2 The farmer starts at number ‘56’. ‘56’ represents row 5 and column 6. The farmer circles this plant on Fig. 3.3. The farmer ignores a number in Fig. 3.2 if: • any part of the number is greater than 6 • a number is repeated. Fig. 3.3 shows the area of soybean plants the farmer investigates. column number 0 1 2 3 4 5 6 0 1 2 row 3 number 4 5 6 Fig. 3.3 (i) The farmer samples a total of 6 plants. The first 3 soybean plants selected from the random number generator are circled. Complete Fig. 3.3 by circling the 3 other soybean plants the farmer samples. [1] (ii) State one benefit of using a random number generator to select the soybean plants. … … [1] (b) The farmer uses a beating tray to investigate insect population. (i) Describe a beating tray method the student can use to estimate the total number of insects on the 49 soybean plants. … … … … … … … … … … [5] (ii) Describe two limitations of using a beating tray for investigating the insect population on soybean plants. 1 … … 2 … … [2] (c) The farmer concludes that the soybean plants are infested with aphids. Aphids are insects that eat soybean plants and reduce crop yield. The farmer introduces the harlequin beetle to the soybean plants. The harlequin beetle is a flying insect and is a predator of the aphids. Fig. 3.4 shows a harlequin beetle. 7 mm Fig. 3.4 The farmer records the population of aphids in 2 different fields. Fig. 3.5 shows the results. Key field 1: no predator field 2: predator added 300 250 200 mean number of aphids 150per leaf predator added to field 2 100 50 00 5 10 15 20 25 30 35 40 45 50 55 60 65 day Fig. 3.5 (i) Name the type of method for controlling the aphid population using a predator. … [1] (ii) Suggest why the predator was not added to field 1. … [1] (iii) Suggest why the aphid population was measured before the predator was added to field 2. … … [1] (iv) Write a conclusion using the data in Fig. 3.5. … … … … … … [3] (v) Suggest why the farmer covers the soybean plants with nets after the predator is added. … … … … [2] (d) The harlequin beetle was introduced to North America and Europe to control aphid populations. The harlequin beetle is now considered to be one of the world’s most invasive species. The harlequin beetle becomes inactive when temperatures are lower than 10 °C. Suggest why climate change could benefit the harlequin beetle. … … [1] (e) Increasing crop productivity by reducing pests is a strategy for managing food security. Hydroponics can also improve food security. (i) Explain how hydroponics improves food security. … … … … … … … … [4] (ii) Describe the limitations of large-scale food stockpiling as a method of reducing food insecurity. … … … … … … [3] (iii) Outline the impacts of food insecurity. … … … … … … … … [4] [Total: 29]

29 marks

Mark scheme: 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;

This question in 8291/23 Oct/Nov 2024

2 Water turbidity measures the cloudiness of water. Turbidity is caused by undissolved solids in water. (a) A student uses a Secchi disc to measure the turbidity of water in four lakes, A, B, C and D. A Secchi disc is a white and black disc. The disc is suspended by a central cord. The cord has markings at 10 cm intervals. Fig. 2.1 shows a Secchi disc in water. water surface cord not to scale Fig. 2.1 The student: • lowers the Secchi disc into the water until the disc is completely invisible (cannot be seen). This depth is recorded as maximum depth. • raises the Secchi disc until the pattern on the disc is just visible. This depth is recorded as minimum depth. • calculates the mean of the maximum and minimum depths and records this as the Secchi depth. Table 2.1 shows the results. Table 2.1 maximum depth minimum depth Secchi depth lake / m / m / m A 3.40 0.20 1.80 B 2.90 0.50 C 5.75 0.30 3.03 D 4.85 0.45 2.65 (i) Calculate the Secchi depth for lake B. Secchi depth for lake B = … m [1] (ii) Suggest two reasons why it is not suitable to use a Secchi disc in some weather conditions. 1 … … 2 … … [2] (iii) The student repeats the investigation twice a week for three months. Explain why recording more than one set of maximum and minimum depths per lake is good sampling practice. … … … … [2] (b) Surface water contains phytoplankton. Phytoplankton are producers. (i) State the source of energy for phytoplankton. … [1] (ii) Explain why chlorophyll concentration is an indicator of primary production in surface water. … … … … [2] (c) The student investigates how Secchi depth relates to the concentration of surface water chlorophyll. Fig. 2.2 shows the results. 7 6 5 Secchi 4 depth / m 3 2 1 0 1 2 5 10 20 50 100 surface water chlorophyll concentration / arbitrary units Fig. 2.2 Write a suitable conclusion from the data in Fig. 2.2. … … … [1] (d) The ‘Secchi Disk Study’ is a crowd sourced investigation into global phytoplankton populations. In the study, people submit Secchi depths from oceans around the world and upload the data to a website. Fig. 2.3 shows the location of the crowd sourced sampling sites up to May 2022. Key sampling site N North Atlantic Ocean North Pacific Ocean South South Atlantic Pacific Indian Ocean Ocean Ocean Fig. 2.3 (i) Outline the benefits and limitations of obtaining scientific data by crowd sourcing. benefits … … … … limitations … … … … [4] (ii) Suggest how climate change could decrease phytoplankton populations. Give reasons for your answer. … … … … … … [3] (e) An electronic hand-held meter is used to measure turbidity at 70 locations along the length of a river. Fig. 2.4 shows the results. 60 50 40 turbidity / arbitrary 30 units 20 10 0 0 10 20 30 40 50 60 70 location number Fig. 2.4 (i) State which location has the greatest turbidity. location number = … [1] (ii) State the turbidity at location 41. turbidity = … arbitrary units [1] (f) Fig. 2.5 shows the relationship between fish activity and turbidity. 100 000 reduced growth 10 000 rates death fish abandon + cover 1000 + turbidity delayed hatching avoidance behaviour / arbitrary rates detected units + increased respiration + 100 + feeding stress reduced feeding rates fish start to + show signs increased coughing 10 of stress rates hours days weeks months time Fig. 2.5 The turbidity at location 7 remains at 48 arbitrary units for 3 weeks. Describe the impacts of this turbidity on fish activity. … … … … [2] [Total: 20]

20 marks

Mark scheme: 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;

This question in 8291/21 May/June 2025

1 (a) A questionnaire is used to obtain the opinions of people in different regions on the importance of recycling. Fig. 1.1 shows the results. Key extremely important important not important 100 90 80 70 percentage of 60 responses 50 40 30 20 10 0 Europe Africa North Oceania America region Fig. 1.1 Compare the percentage of people in different regions who think recycling is extremely important. … … … … … … [3] (b) (i) There are three choices in the response area of this questionnaire: • extremely important • important • not important. Suggest one benefit and one limitation of this type of response area for a questionnaire. benefit … … limitation … … [2] (ii) A total of 11 500 local business owners and homeowners were used to complete the questionnaire. Suggest one benefit of asking these people to complete the questionnaire. … … [1] (c) Some people do not recycle even though they say that recycling is extremely important. Suggest three reasons why people do not recycle. 1 … 2 … 3 … [3] (d) Plastic waste can end up in the ocean. (i) Describe the impacts of plastics in oceans on marine life. … … … … … … … … [4] (ii) Some fishing boat owners collect the plastic waste. The plastic waste is converted into plastic fibres. Cotton is a plant which is harvested for its fibres. Both plastic fibres and cotton fibres are used to make clothing. Suggest two advantages for the environment of using plastic fibres compared to cotton fibres. 1 … … 2 … … [2] (e) A report states that 25% of plastic waste is incinerated. Describe the benefits and limitations of incineration as a method of plastic waste disposal. benefits … … … … limitations … … … … [4] [Total: 19]

19 marks

Mark scheme: 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;

This question in 8291/22 May/June 2025

2 Albatross are birds. Many of the 22 species of albatross are listed by the International Union for Conservation of Nature (IUCN) Red List. (a) Describe how the IUCN Red List helps conserve biodiversity. … … … … [2] (b) Albatrosses make mud nests on the ground to lay their eggs. Fig. 2.1 shows albatrosses on the mud nests. mud nest Fig. 2.1 Suggest two reasons why these mud nests are at risk from climate change. 1 … … 2 … … [2] (c) Fig. 2.2 shows a food web for albatrosses. gulls small fish albatross octopus squid phytoplankton shrimp large fish Fig. 2.2 Write a food chain for the albatross. Start the food chain with a producer and include a total of four trophic levels. … [2] (d) Mercury is a toxic metal. The concentration of mercury in organisms in the food web in Fig. 2.2 is investigated. For albatrosses, their feathers are analysed. For the other organisms in the food web, their flesh is analysed. (i) Suggest two reasons why only the feathers are analysed for albatrosses. 1 … … 2 … … [2] (ii) The mean level of mercury in the prey of the albatross was 0.0005 μg per g. Circle the predicted mean level of mercury in albatrosses. Explain your answer. 0.0001 μg per g 0.0005 μg per g 3.88 μg per g … … [2] (e) Albatrosses can travel over 1500 km a day to find food. Suggest how radio tracking is used to record the distances albatrosses travel to find food. … … … … [2] (f) Satellite images from space are used to determine albatross population near Antarctica. Fig. 2.3 shows a satellite image of some nesting albatrosses. Key albatross 0 3 m Fig. 2.3 (i) Record the number of albatrosses shown in Fig. 2.3 as a tally. number of albatrosses [1] (ii) Crowd sourcing is used to count the number of albatrosses on each satellite image. Describe what is meant by crowd sourcing. … … [1] (iii) Suggest the benefits and limitations of using satellite images to determine the population of albatrosses. benefits … … … … limitations … … … … [4] (g) Different species of albatross build nests in the same area. A scientist uses Simpson’s index of diversity to investigate the different species of albatross in an area. D = 1 – (∑(nN) 2) State what each of the letters represent in this formula. ∑ … n … N … [3] [Total: 21]

21 marks

Mark scheme: 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);

This question in 8291/22 Oct/Nov 2025

4 (a) Fig. 4.1 shows a map of drought risk. Content removed due to copyright restrictions. Fig. 4.1 (i) Describe the distribution of countries with high drought risk. … … … … … [3] (ii) A lack of drinking water is an impact of drought. This can cause deaths. State three other impacts of drought. 1 … 2 … 3 … [3] (b) Fig. 4.2 shows climate data from a weather station in the Northern Territory, Australia. Content removed due to copyright restrictions. Fig. 4.2 (i) State the highest mean temperature. … °C [1] (ii) State which three months had the greatest mean rainfall. … and … and … [1] (iii) Suggest why the rate of primary productivity decreases during June to August near the location of this weather station. Use Fig. 4.2 to support your answer. … … … … [2] (c) Some areas of the Northern Territory have a grassland biome. Describe the soil type in a grassland biome. … … … … [2] (d) Cane toads are an invasive species in the Northern Territory. Explain the impacts of invasive species on biodiversity. … … … … … … [3] [Total: 15]

15 marks

Mark scheme: 4(a)(i) any three from: 3 M1 most of Europe / Eastern Europe / Southern Europe; M2 South Asia / Southeast Asia; M3 (mostly) north of Tropic of Cancer / in the region of Tropic of Cancer; M4 some countries bordering Equator; M5 named country e.g. Moldova / Ukraine / Bangladesh / India / Serbia; 4(a)(ii) any three from: 3 M1 wild fires; M2 crop failure / reduced crop yield; M3 food insecurity / famine / food shortages; M4 water insecurity / poor sanitation / disease; M5 lower HEP production; 4(b)(i) 32; 1 4(b)(ii) Jan and Feb and Dec; 1 4(b)(iii) any two from: 2 M1 low(est) rainfall / rainfall less than 5 mm; M2 water needed for photosynthesis; M3 green plants convert carbon dioxide and water to glucose and oxygen; 4(c) any two from: 2 M1 thick or deep layer of humus / thick or deep layer of decaying plants or animals; M2 high nutrients / high fertility / are fertile / high organic content; M3 reference to, moisture content / porosity / pH / colour; 4(d) any three from: 3 M1 compete with native organisms (for resources); M2 disrupt food chains; M3 spread disease; M4 alter habitats; M5 (leads to) loss of biodiversity / extinction (of native species);

This question in 8291/22 Oct/Nov 2025

2 Rhinoceros are at risk from climate change. (a) A scientist uses capture-mark-recapture to record the number of rhinoceros in an area. (i) State one negative impact of this method of biodiversity investigation. … … [1] (ii) The scientist uses the Lincoln index to estimate population size. n1 × n2 N = m2 State what each of the letters represent in this formula. n1 … n2 … m2 … [3] (c) Fig. 2.2 shows the greater one-horned rhinoceros in Chitwan National Park in Nepal. Fig. 2.2 Fig. 2.3 shows the number of rhinoceros in the Chitwan region from 1950 to 2000. 900 800 700 600 500 number of rhinoceros 400 300 200 100 0 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 year Fig. 2.3 (i) Use Fig. 2.3 to calculate the 5-year period with the greatest percentage change in the number of rhinoceros. Circle your answer. 1950–1955 1955–1960 1970–1975 1975–1980 [1] (ii) Suggest three reasons for the change in the number of rhinoceros from 1970 to 2000. 1 … 2 … 3 … [3] (d) Fig. 2.4 shows climate data for Chitwan National Park. Content removed due to copyright restrictions. Fig. 2.4 (i) Identify which month has the greatest range in temperature. … [1] (ii) Calculate the temperature range for September. … °C [1] (iii) Use Fig. 2.4 to suggest why death by drowning is common for the rhinoceros in the Chitwan region. Explain your answer. … … … … … [3] (iv) In 2020, mounds of soil 40 m × 30 m × 2 m were created in Chitwan National Park. Suggest how these mounds reduce the number of deaths of rhinoceros by drowning. … … [1] (v) Relocation of rhinoceros is a conservation strategy. State two biotic factors that can negatively affect the success of this strategy. 1 … 2 … [2] [Total: 19]

16 marks

Mark scheme: 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;

This question in 8291/23 Oct/Nov 2025