4 (a) Fig. 4.1 shows some information about feeding relationships in a national park. • Lions are the top predator. Lions eat jackals. • Goats eat grass. • Goats are eaten by jackals. Fig. 4.1 (i) Use the information in Fig. 4.1 to construct a food chain containing all the organisms. [2] (ii) Use the information in Fig. 4.1 to identify the: producer … secondary consumer. … [2] (b) State the principal source of energy for all food chains. … [1] (c) Table 4.1 shows the number and types of teeth for goats and humans. Table 4.1 type of teeth number in goats number in humans incisors 8 8 canines 0 4 premolars 12 8 molars 12 12 (i) Goats have a greater total number of premolar and molar teeth than humans. Describe two other differences between the types and number of teeth in goats and humans. 1 … … 2 … … [2] (ii) Goats are herbivores. Humans are able to gain their energy by eating both animals and plants. Suggest reasons why goats have a greater total number of premolar and molar teeth than humans. … … … [2] (iii) Circle the top two layers in a human tooth. cement dentine enamel gum pulp nerve [2] [Total: 11]

4(a)(i) organisms in correct order ; all arrows drawn in the correct direction ; 2 4(a)(ii) producer grass ; secondary consumer jackal ; 2 4(b) the Sun ; 1 4(c)(i) (goats have) more premolar teeth than humans ; (goats have) fewer / no, canine teeth ; 2 4(c)(ii) goats, gain (all) their energy from plant material / only eats plants ; plant material requires more chewing / breaking down ; molars / premolars needed for chewing ; max 2 2 4(c)(iii) enamel ; dentine ; 2

4 (a) Fig. 4.1 shows part of a desert food web. yucca plant prickly pear rabbit rat fox hawk Fig. 4.1 (i) Identify the name of one producer in Fig. 4.1. … [1] (ii) Identify the name of one herbivore in Fig. 4.1. … [1] (iii) Identify the name of an organism that can be classified as both a secondary and tertiary consumer. … [1] (iv) Use Fig. 4.1 to construct a food chain containing four organisms. … [2] (b) A new species is introduced that eats yucca plants. Explain the effect this has on the population of rabbits. … … … … [2] (c) State the term used to describe organisms that get their energy from dead organic matter. … [1] (d) State the principal source of energy for all food chains. … [1] (e) Plants play an important role in the carbon cycle. Describe how an increase in plant population affects the concentration of carbon dioxide in the atmosphere. … … … … [2] [Total: 11]

4(a)(i) yucca plant / prickly pear ; 1 4(a)(ii) rat / rabbit ; 1 4(a)(iii) hawk ; 1 4(a)(iv) yucca plant → rabbit → fox → hawk or prickly pear → rat → fox → hawk or prickly pear → rabbit → fox → hawk correct organisms ; correct arrows (direction of energy transfer) ; 2 4(b) number of rabbits decrease ; more competition for food / less food to eat ; 2 4(c) decomposers ; 1 4(d) the Sun ; 1 4(e) more carbon dioxide removed ; used as material for photosynthesis ; 2

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) Organisms and their environment past paper questions

Revise IGCSE Co-ordinated Sciences (0654) — Organisms and their environment 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.

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

Organisms and their environment in IGCSE Co-ordinated Sciences 0654 exams, 2020–2025

Across 2020–2025, Organisms and their environment accounted for 162 questions worth 529 marks in Cambridge IGCSE Co-ordinated Sciences (0654) papers.

By year
Year	Questions	Marks
2020	23	73
2021	29	93
2022	25	72
2023	28	89
2024	36	97
2025	21	105

Most-tested subtopics

B18.2 Food chains and food webs332 marks
B18.1 Energy flow185 marks
B18.3 Carbon cycle128 marks

Appears in

Paper 1 · 59 qs
Paper 2 · 61 qs
Paper 3 · 20 qs
Paper 4 · 19 qs
Paper 5 · 1 q
Paper 6 · 2 qs

All most-tested Co-ordinated Sciences topics

2021 May/Jun · Paper 3 · Q4 · 11 marks
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2021 Oct/Nov · Paper 3 · Q4 · 11 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
Marking scheme
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2021 Feb/Mar · Paper 1 · Q12 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 1 Q12
Answer: D
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