Carbon cycle — Paper 1 · IGCSE Sciences - Co-ordinated (Double) 0654

13 Which organisms increase the amount of nitrogen gas in the air? A decomposing bacteria B denitrifying bacteria C nitrifying bacteria D nitrogen fixing bacteria

1 marks

Answer: B

This question in 0654/11 May/June 2006

13 The diagram shows a simple carbon cycle. Which line should have an arrow at both ends? carbon dioxide in the atmosphere B A C carbon in decomposers carbon carbon in faeces in grass carbon in D rabbits

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2006

13 What can lead to global warming? 0 0O WwW > nitrogen fixation x < x deforestation \ x x denitrification ~*~ KOM burning of fossil fuels KS

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2007

26 The diagram shows waste organic material decaying. tap gas decaying waste organic material What is formed when the gas is burned? A carbon dioxide and water B carbon dioxide only C carbon monoxide only D water only

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2008

13 The diagram shows part of the carbon cycle in a forest. The numbers represent different processes. carbon dioxide in the air 1 2 trees respiration decay 3 animals humus death Which of these processes is reduced in rate as a result of deforestation? A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0654/11 May/June 2009

13 The diagram shows part of the water cycle. water vapour in the atmosphere rain evaporation transpiration respiration water in the sea, lakes animals plants Which returns most water to the atmosphere? A evaporation from the sea and lakes B respiration from animals C respiration from plants D transpiration

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2009

13 The diagram shows a simple carbon cycle. Which line should have an arrowhead at both ends? carbon dioxide in the atmosphere B A C carbon in decomposers carbon carbon in faeces in grass carbon in D rabbits

1 marks

Answer: C

This question in 0654/11 May/June 2010

12 The diagram shows a simple carbon cycle. Which line should have an arrowhead at both ends? carbon dioxide in the atmosphere B A C carbon in decomposers carbon carbon in faeces in grass carbon in D rabbits

1 marks

Answer: C

This question in 0654/12 May/June 2010

14 During the weathering of rocks, which process does not take place? A chemical change B fixation of nitrogen C physical change D release of salts into the soil

1 marks

Answer: B

This question in 0654/12 May/June 2010

13 The diagram shows part of the carbon cycle which includes a food chain. carbon dioxide in the air 1 2 4 producer dead consumer 3 consumer consumer 5 Which arrows are part of the food chain? A 1 and 2 B 2 and 3 C 3 and 5 D 4 and 5

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2010

10 The diagram shows part of the carbon cycle which includes a food chain. carbon dioxide in the air 1 2 4 producer dead consumer 3 consumer consumer 5 Which arrows are part of the food chain? A 1 and 2 B 2 and 3 C 3 and 5 D 4 and 5

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2010

13 What can lead to global warming? deforestation ° un "9 of A v v B v x Cc x v D x x

1 marks

Answer: A

This question in 0654/11 May/June 2012

13 The diagram shows part of the carbon cycle. carbon dioxide in the air 1 4 carbon 2 3 compounds carbon carbon in fossil fuels compounds compounds in animals in plants carbon compounds in dead matter Where are photosynthesis and respiration happening? photosynthesis respiration A 3 2 B 3 4 C 4 1 D 4 3

1 marks

Answer: D

This question in 0654/12 May/June 2012

13 The diagram shows part of the carbon cycle. carbon dioxide in the air 1 4 carbon 2 3 compounds carbon carbon in fossil fuels compounds compounds in animals in plants carbon compounds in dead matter Where are photosynthesis and respiration happening? photosynthesis respiration A 3 2 B 3 4 C 4 1 D 4 3

1 marks

Answer: D

This question in 0654/13 May/June 2012

13 The diagram shows part of the carbon cycle. During which stage is oxygen produced? carbon dioxide in the air A D carbohydrates, fats and proteins in dead B animals and plants carbon compounds C in fuels, e.g. peat and coal death carbohydrates, fats death and proteins in animals carbohydrates and proteins in green plants

1 marks

Answer: C

This question in 0654/11 May/June 2013

13 Which chemical contains carbon atoms that are involved in the carbon cycle? A ammonia B protein C sulfuric acid D water

1 marks

Answer: B

This question in 0654/12 May/June 2013

13 The diagram shows part of the carbon cycle. During which stage is oxygen produced? carbon dioxide in the air A D carbohydrates, fats and proteins in dead B animals and plants carbon compounds C in fuels, e.g. peat and coal death carbohydrates, fats death and proteins in animals carbohydrates and proteins in green plants

1 marks

Answer: C

This question in 0654/13 May/June 2013

13 The diagram shows part of the carbon cycle in a forest. The numbers represent different processes. carbon dioxide in the air 1 2 trees decay respiration 3 animals dead animals and trees death Which of these processes is reduced as a result of deforestation? A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2013

12 The diagram shows part of the carbon cycle in a forest. The numbers represent different processes. carbon dioxide in the air 1 2 trees decay respiration 3 animals dead animals and trees death Which of these processes is reduced as a result of deforestation? A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0654/12 Oct/Nov 2013

13 The diagram shows part of the carbon cycle in a forest. The numbers represent different processes. carbon dioxide in the air 1 2 trees decay respiration 3 animals dead animals and trees death Which of these processes is reduced as a result of deforestation? A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2013

13 The diagram shows part of the carbon cycle. carbon dioxide in the atmosphere X factories and power stations plants animals fossil fuels What process does X represent? A combustion B decay C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/11 May/June 2015

13 In the carbon cycle, which process removes carbon dioxide from the atmosphere? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/12 May/June 2015

13 Deforestation can cause global warming because it leads to A build up of carbon dioxide. B extinction of species. C flooding of low-lying areas. D loss of soil.

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2015

12 Which chemical supplies carnivores with energy and plays a part in the carbon cycle? A carbon dioxide B fibre (roughage) C glucose D water

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2015

13 The diagram shows part of the carbon cycle. Which arrow shows respiration by plants? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2015

9 What would be the effects of deforestation on the level of atmospheric carbon dioxide and the amount of soil? carbon dioxide amount of soil level A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: C

This question in 0654/11 May/June 2017

11 The list shows some effects of human activities. P global warming Q loss of fossil fuels R water pollution S flooding Which effects can be the result of deforestation? A P and Q B P and S C Q and R D R and S

1 marks

Answer: B

This question in 0654/12 May/June 2017

13 The concentration of carbon dioxide in the atmosphere has increased during the last 200 years. What has contributed to this change? A burning large areas of forest B increased use of pesticides C planting more crops D using fewer fossil fuels

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2017

12 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2018

12 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2018

13 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2018

13 In the carbon cycle, which process decreases the level of carbon dioxide in the atmosphere? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/11 May/June 2019

13 What changes in combustion and deforestation increase carbon dioxide in the atmosphere? A decreased combustion, decreased deforestation B decreased combustion, increased deforestation C increased combustion, decreased deforestation D increased combustion, increased deforestation

1 marks

Answer: D

This question in 0654/12 Oct/Nov 2019

13 The diagram shows some of the processes in the carbon cycle. Which process is respiration? carbon dioxide in the atmosphere D A plants B dead plants and animals animals C microorganisms

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2019

13 What could deforestation cause? A a decrease in carbon dioxide levels and a decrease in flooding B a decrease in carbon dioxide levels and an increase in flooding C an increase in carbon dioxide levels and a decrease in flooding D an increase in carbon dioxide levels and an increase in flooding

1 marks

Answer: D

This question in 0654/12 May/June 2020

13 What does not contribute to the carbon cycle? A combustion B deforestation C transpiration D photosynthesis

1 marks

Answer: C

This question in 0654/11 May/June 2021

13 Which process removes carbon dioxide from the atmosphere? A combustion B photosynthesis C respiration D transpiration

1 marks

Answer: B

This question in 0654/12 May/June 2021

13 Which process removes carbon dioxide from the atmosphere? A combustion B photosynthesis C respiration D transpiration

1 marks

Answer: B

This question in 0654/13 May/June 2021

13 The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration? CO2 B C A green D animals plants fossil fuels

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2021

13 The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration? CO2 B C A green D animals plants fossil fuels

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2021

13 The diagram shows a simplified carbon cycle. Which labelled arrow represents respiration? CO2 B C A green D animals plants fossil fuels

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2021

13 The diagram shows part of the carbon cycle. carbon dioxide in atmosphere compounds containing X Y Y carbon in dead matter compounds containing compounds containing Z carbon in plants carbon in animals What are processes X, Y and Z? X Y Z A decomposition respiration feeding B photosynthesis respiration feeding C photosynthesis decomposition respiration D decomposition photosynthesis respiration

1 marks

Answer: B

This question in 0654/12 Feb/March 2022

13 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/11 May/June 2022

13 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/12 May/June 2022

13 The diagram shows part of the carbon cycle. Which arrow represents plant respiration? carbon compounds A in the air B carbon compounds carbon compounds in plants C in rocks, sea and soil D carbon compounds in animals

1 marks

Answer: B

This question in 0654/13 May/June 2022

13 A student draws four different attempts at part of the carbon cycle. Which diagram is correct? A B air air (atmosphere) (atmosphere) photosynthesis feeding respiration respiration animals plants animals plants photosynthesis feeding C D air air (atmosphere) (atmosphere) respiration photosynthesis photosynthesis feeding animals plants animals plants feeding respiration

1 marks

Answer: A

This question in 0654/12 Feb/March 2023

13 The graph shows the change in atmospheric carbon dioxide levels over time. 400 390 380 mass of 370 carbon 360 dioxide 350 / arbitrary 340 units 330 320 310 300 1958 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013 year A reduction of which process could cause the change in carbon dioxide shown? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/11 May/June 2023

13 Which row about the effects of deforestation is correct? amount of risk of flooding carbon dioxide in atmosphere A decreased decreased B decreased increased C increased decreased D increased increased

1 marks

Answer: D

This question in 0654/12 May/June 2023

13 Which row about the effects of deforestation is correct? amount of risk of flooding carbon dioxide in atmosphere A decreased decreased B decreased increased C increased decreased D increased increased

1 marks

Answer: D

This question in 0654/13 May/June 2023

13 Forests are cut down and burnt in deforestation programmes. As a result of this, which gas in the atmosphere increases in concentration? A carbon dioxide B hydrogen C nitrogen D oxygen

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2023

13 The concentration of carbon dioxide in the atmosphere has increased during the last 200 years. What has contributed to this increase? A burning large areas of forest B increasing use of pesticides C planting more crops D using fewer fossil fuels

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2023

13 Which row describes the effects of deforestation? level of risk of carbon dioxide flooding in the air A decreases decreases B decreases increases C increases decreases D increases increases

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2023

13 Which process is not part of the carbon cycle? A combustion B fossilisation C transpiration D photosynthesis

1 marks

Answer: C

This question in 0654/12 Feb/March 2024

13 Which process removes carbon dioxide from the atmosphere? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/11 May/June 2024

13 The diagram shows gas exchange by two groups of organisms during the hours of darkness. the atmosphere P S Q R producers consumers Which letters represent gases that are part of the carbon cycle? A P and Q B P and R C P and S D Q and S

1 marks

Answer: B

This question in 0654/12 May/June 2024

13 The diagram shows gas exchange by two groups of organisms during the hours of darkness. the atmosphere P S Q R producers consumers Which letters represent gases that are part of the carbon cycle? A P and Q B P and R C P and S D Q and S

1 marks

Answer: B

This question in 0654/13 May/June 2024

13 The diagram shows part of the carbon cycle. carbon dioxide in the atmosphere X factories and power stations plants animals fossil fuels Which process does X represent? A combustion B decomposition C photosynthesis D respiration

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2024

13 Which row about a process in the carbon cycle is correct? effect on level process of atmospheric carbon dioxide A combustion decreases B decomposition increases C fossilisation increases D respiration decreases

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2024

13 Which row about a process in the carbon cycle is correct? effect on level process of atmospheric carbon dioxide A combustion decreases B decomposition increases C fossilisation increases D respiration decreases

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2024

13 What are undesirable effects of deforestation? A habitat creation and decreased carbon dioxide in the atmosphere B habitat creation and increased carbon dioxide in the atmosphere C habitat destruction and decreased carbon dioxide in the atmosphere D habitat destruction and increased carbon dioxide in the atmosphere

1 marks

Answer: D

This question in 0654/12 Oct/Nov 2025

13 What are undesirable effects of deforestation? A habitat creation and decreased carbon dioxide in the atmosphere B habitat creation and increased carbon dioxide in the atmosphere C habitat destruction and decreased carbon dioxide in the atmosphere D habitat destruction and increased carbon dioxide in the atmosphere

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2025