7 (a) A scientist investigates the effect of immersion of plant cells in different concentrations of sugar solution. Fig. 7.1 shows the appearance of the plant cells before immersion. Fig. 7.1 Beakers A–D contain different concentrations of sugar solution. Some plant cells are placed in each solution and left for an hour. Table 7.1 shows the results. Table 7.1 beaker A B C D appearance of plant cells after immersion (i) Describe the change seen to the plant cells placed in beaker A in Table 7.1. … … [1] (ii) Suggest which beaker contains the solution with the same concentration as the plant cells. Give a reason for your answer. beaker … reason … [2] (b) Water enters the plant through the root hair cells. Complete the flow chart to show the pathway of water through the cells of a plant. root hair cell … xylem … [2] (c) Xylem transports water through the plant stem. Name the tissue that transports sugars through the plant stem. … [1] (d) Water and carbon dioxide are raw materials required for photosynthesis. Name two other requirements for photosynthesis. 1 … 2 … [2] (e) Protecting land from deforestation helps stop the loss of soil. This is because tree roots hold the soil together, stopping it being washed away. Suggest two other benefits of protecting land from deforestation. 1 … … 2 … … [2] [Total: 10]

7(a)(i) the cell, swells / increases in size ; 1 7(a)(ii) B ; the cell has not changed ; 2 7(b) root cortex (cell) ; mesophyll (cell) ; 2 7(c) phloem ; 1 7(d) light ; chlorophyll ; AVP ; 2 7(e) any two from prevents extinction of animals ; conserves habitat ; protects food sources (for humans) ; maintains food, chains / webs ; maintains, wood / fuel (resources) ; idea of protecting natural beauty ; AVP ; max 2 2 (a)(i) To earn this mark, you must describe the change as the cell 'swells / increases in size'. (a)(ii) To earn these two marks, you must identify beaker 'B' and explain that 'the cell has not changed'. (b) To earn these two marks, you must correctly complete the flow chart with 'root cortex (cell)' and 'mesophyll (cell)'. (c) To earn this mark, you must name 'phloem' as the tissue that transports sugars. (d) To earn these two marks, you must state 'light' and 'chlorophyll' as factors required for photosynthesis, or provide another valid point. (e) To earn these two marks, you must state any two valid reasons for conserving plant species, such as preventing animal extinction, conserving habitats, protecting food sources, maintaining food chains/webs, maintaining wood/fuel resources, or protecting natural beauty.

7 (a) A scientist investigates the effect of immersion of plant cells in different concentrations of sugar solution. Fig. 7.1 shows the appearance of the plant cells before immersion. Fig. 7.1 Beakers A–D contain different concentrations of sugar solution. Some plant cells are placed in each solution and left for an hour. Table 7.1 shows the results. Table 7.1 beaker A B C D appearance of plant cells after immersion (i) Describe the change seen to the plant cells placed in beaker A in Table 7.1. … … [1] (ii) Suggest which beaker contains the solution with the same concentration as the plant cells. Give a reason for your answer. beaker … reason … [2] (b) Water enters the plant through the root hair cells. Complete the flow chart to show the pathway of water through the cells of a plant. root hair cell … xylem … [2] (c) Xylem transports water through the plant stem. Name the tissue that transports sugars through the plant stem. … [1] (d) Water and carbon dioxide are raw materials required for photosynthesis. Name two other requirements for photosynthesis. 1 … 2 … [2] (e) Protecting land from deforestation helps stop the loss of soil. This is because tree roots hold the soil together, stopping it being washed away. Suggest two other benefits of protecting land from deforestation. 1 … … 2 … … [2] [Total: 10]

7(a)(i) the cell, swells / increases in size ; 1 7(a)(ii) B ; the cell has not changed ; 2 7(b) root cortex (cell) ; mesophyll (cell) ; 2 7(c) phloem ; 1 7(d) light ; chlorophyll ; AVP ; 2 7(e) any two from prevents extinction of animals ; conserves habitat ; protects food sources (for humans) ; maintains food, chains / webs ; maintains, wood / fuel (resources) ; idea of protecting natural beauty ; AVP ; max 2 2 (a)(i) To earn this mark, you must describe the change as the cell 'swells / increases in size'. (a)(ii) To earn these two marks, you must identify 'B' as the beaker and explain that 'the cell has not changed'. (b) To earn these two marks, you must correctly complete the flow chart with 'root cortex (cell)' and 'mesophyll (cell)'. (c) To earn this mark, you must name 'phloem' as the tissue that transports sugars. (d) To earn these two marks, you must state 'light' and 'chlorophyll' as two factors required for photosynthesis, or provide another valid point. (e) To earn these two marks, you must state two valid reasons for conserving endangered species, such as preventing extinction, conserving habitats, protecting food sources, maintaining food chains/webs, maintaining wood/fuel resources, or protecting natural beauty.

10 Fig. 10.1 is a diagram showing part of the carbon cycle. carbon dioxide in the atmosphere dead organisms fossil fuels X industry decomposition photosynthesis Fig. 10.1 (a) Name the process occurring at X in Fig. 10.1. … [1] (b) When deforestation occurs there is a build-up of carbon dioxide in the atmosphere. (i) List two other negative effects of deforestation. 1 … 2 … [2] (ii) Stopping deforestation will reduce the build-up of carbon dioxide in the atmosphere. Use the information in Fig. 10.1 to suggest two other ways we can reduce the build-up of carbon dioxide in the atmosphere. 1 … … 2 … … [2] (c) Table 10.1 shows some features of respiration and photosynthesis. Place ticks (3) in the boxes to show the features of each process. Table 10.1 process produces carbon dioxide produces oxygen requires light energy produces carbohydrates photosynthesis respiration [4] (d) Water is one of the substances required by plants and is also lost by plants during transpiration. (i) State the name of the vessels that transport water through a plant. … [1] (ii) Complete the sentences to define the term transpiration. Transpiration is loss of water vapour from plant … by evaporation of water at the surfaces of the mesophyll … followed by diffusion of water vapour through the … [3] [Total: 13]

10(a) fossilisation ; 1 10(b)(i) any two from: habitat destruction ; extinction ; loss of soil ; flooding ; AVP ; 2 10(b)(ii) replant / plant more trees ; reduce, combustion of fossil fuels / emissions by industry ; 2 10(c)     ;;;; 4 10(d)(i) xylem ; 1 10(d)(ii) leaves ; cells ; stomata ; 3 (a) This mark is awarded for correctly naming 'fossilisation' as the process occurring at X. (b)(i) You need to list any two negative effects of deforestation, such as habitat destruction, extinction, loss of soil, or flooding. (b)(ii) You must suggest two ways to reduce carbon dioxide build-up, such as replanting/planting more trees or reducing the combustion of fossil fuels/emissions by industry. (c) You earn these marks by correctly ticking all four boxes. (d)(i) This mark is awarded for correctly identifying 'xylem'. (d)(ii) You need to identify 'leaves', 'cells', and 'stomata' as the parts involved.

4 (a) Table 4.1 shows the forest area in two different continents, A and B, in 1990 and 2010. Table 4.1 continent total forest area / thousand km2 in 1990 in 2010 A 9460 8640 B 9890 10050 (i) Compare the total forest area for continents A and B between the years 1990 and 2010. Use comparative data from Table 4.1 in your answer. … … … … … … [3] (ii) The change to the total forest area for continent A may affect the animals living in the forest. Describe three ways the animals may be affected. 1 … … 2 … … 3 … … [3] (iii) Explain two ways that deforestation causes the carbon dioxide concentration in the atmosphere to increase. 1 … … 2 … … [2] (b) Plants in a forest will compete for light. Auxin is a hormone that is responsible for the chemical control of shoot growth. Complete the sentences to describe how auxin causes shoots to grow towards the light. Auxin is made in the shoot … and moves and spreads through the plant. It collects on the … side of the shoot. Auxin stimulates cell …so this side will grow more. This results in the shoot bending towards the light. This growth response to light is called … . [4] [Total: 12]

4(a)(i) Any two from: forest cover decreases in continent A ; forest cover increases in continent B ; B always has more forest cover than A ; and data manipulation with correct units ; 2 + 1 4(a)(ii) loss of food / disruption to food chain / web ; loss of habitat ; extinction ; migration ; 2 4(a)(iii) less photosynthesis so less carbon dioxide removed ; (more) combustion (of trees) so (more) carbon dioxide produced; 2 4(b) tip(s) ; shaded ; elongation ; phototropism ; 4 To earn marks, you must compare the forest area changes in continents A and B, using specific data from the table to support your comparison. For animal effects, you need to describe three consequences such as loss of food, habitat, or extinction. For the effect on the atmosphere, you must explain how less photosynthesis and more combustion lead to increased carbon dioxide.

Cambridge IGCSE Co-ordinated Sciences · 0654

IGCSE Co-ordinated Sciences (0654) Human influences on ecosystems past paper questions

Revise IGCSE Co-ordinated Sciences (0654) — Human influences on ecosystems with real Cambridge past-paper questions grouped by topic, each shown with its marking scheme. Working one topic at a time targets exactly the skill each question tests.

49 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

Human influences on ecosystems in IGCSE Co-ordinated Sciences 0654 exams, 2020–2025

Across 2020–2025, Human influences on ecosystems accounted for 60 questions worth 295 marks in Cambridge IGCSE Co-ordinated Sciences (0654) papers.

By year
Year	Questions	Marks
2020	12	40
2021	8	60
2022	9	17
2023	14	56
2024	5	43
2025	12	79

Most-tested subtopics

B19.1 Habitat destruction233 marks
B19.2 Conservation117 marks

Appears in

Paper 1 · 17 qs
Paper 2 · 16 qs
Paper 3 · 15 qs
Paper 4 · 12 qs

All most-tested Co-ordinated Sciences topics

2021 May/Jun · Paper 3 · Q7 · 10 marks
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2021 May/Jun · Paper 3 · Q7 · 10 marks
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2021 Oct/Nov · Paper 3 · Q10 · 13 marks
Marking scheme
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2021 May/Jun · Paper 4 · Q4 · 12 marks
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2021 Feb/Mar · Paper 1 · Q13 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 1 Q13
Answer: D
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