Biology 0610 · IGCSE
Nutrient cycles
100 practice questions on Nutrient cycles, with worked solutions and instant marking.
Which processes form part of the carbon cycle?
Feb/March 2016
A rise in human population is associated with a shift in carbon dioxide concentration in the atmosphere. Fig. 4.1 plots the carbon dioxide concentration from 1958 to 2010, measured at Mauna Loa, Hawaii.
Feb/March 2016
The diagram illustrates part of the carbon cycle. What is represented by arrow X?
Feb/March 2017
The diagram illustrates the water cycle. What processes are shown by Y and Z?
Feb/March 2017
Which process causes nitrates to be removed from soils?
Feb/March 2017
In what way does the removal of trees add to the greenhouse effect?
Feb/March 2017
The diagram illustrates part of the carbon cycle. Which process lowers the carbon dioxide content in the atmosphere?
Feb/March 2018
Deforestation has harmful impacts on the environment. Which impact contributes most to global warming?
Feb/March 2018
The diagram illustrates a section of the carbon cycle. Which process decreases the carbon dioxide content in the atmosphere?
Feb/March 2018
Fig. 10.1 illustrates a section of the water cycle. The letters stand for the processes occurring within the water cycle.
Feb/March 2018
Which process is it when water drops from clouds to the ground?
Feb/March 2019
Which organisms cause nitrate ions to be removed from the soil?
Feb/March 2019
The diagram illustrates part of the carbon cycle. Which process takes place at Y?
Feb/March 2020
How would reducing forest cover affect the concentration of carbon dioxide in the atmosphere?
Feb/March 2021
When nitrates get into a lake, they trigger a fast increase in algae growing across the water surface. As a result, the following changes happen in the lake: 1 The amount of dissolved oxygen in the water falls. 2 Fish and other aquatic animals die. 3 Aerobic respiration in decomposers rises. 4 Producers die and decomposition rises. What is the correct sequence for these changes?
Feb/March 2021
Which type of bacteria would, through its activity, leave the soil short of nitrates?
Feb/March 2021
The diagram illustrates the carbon cycle. Which labelled processes show respiration?
Feb/March 2023
In the nitrogen cycle, which processes are labelled 1 and 2?
Feb/March 2023
Fig. 6.1 shows a diagram of part of the carbon cycle.
Feb/March 2023
Which row indicates part of the nitrogen cycle?
Feb/March 2024
The processes shown influence the concentration of carbon dioxide in the atmosphere. Which processes cause the concentration of carbon dioxide in the atmosphere to rise?
Feb/March 2025
In what way does eutrophication cause fish to die?
Feb/March 2025
The diagram shows the carbon cycle. Which process does arrow X show?
May/June 2016
Which process is not included in the water cycle?
May/June 2016
The diagram illustrates a section of the nitrogen cycle. At which stage is denitrification taking place?
May/June 2016
Which process is not included in the water cycle?
May/June 2016
Which process is performed by bacteria in the root nodules of leguminous plants?
May/June 2016
The diagram illustrates part of the carbon cycle. At which labelled stages does respiration take place?
May/June 2017
By feeding on dead organic matter, fungi can function as decomposers. Which statement describes how this affects the carbon cycle?
May/June 2017
The diagram illustrates a section of the water cycle. Which processes are S and T?
May/June 2017
The processes in 1-4 will change the concentration of carbon dioxide in the atmosphere. 1 increased deforestation 2 increased forestation 3 decreased fossil fuel combustion 4 increased fossil fuel combustion Which of these processes would raise the concentration of carbon dioxide in the atmosphere?
May/June 2017
The diagram illustrates a section of the water cycle. What are processes S and T?
May/June 2017
This investigation examined how fertilisers affected grass yield and species diversity in a grassland ecosystem.
May/June 2017
The diagram illustrates a section of the carbon cycle. Which process is absent from the diagram?
May/June 2018
Which labelled stage of the water cycle represents precipitation?
May/June 2018
Which process leaves the carbon dioxide level in the air unchanged?
May/June 2018
When nitrates enter a lake, they trigger fast algae growth at the water’s surface. As a result, these changes happen in the lake: 1. the concentration of dissolved oxygen in the water decreases 2. fish and other aquatic animals die 3. decomposers increase their aerobic respiration 4. producers die and decomposition rises What is the correct sequence in which these changes take place?
May/June 2018
In what form do plant roots absorb nitrogen?
May/June 2018
Fig. 5.1 illustrates a section of the carbon cycle.
May/June 2018
Which process is included in the carbon cycle?
May/June 2019
The diagram illustrates stages in the water cycle. Which process is shown by the letter X?
May/June 2021
Human activities are altering the concentration of carbon dioxide in the atmosphere. Which activities will cause the concentration of carbon dioxide in the atmosphere to rise?
May/June 2021
The graph illustrates the yearly rate of deforestation and the yearly net emission of carbon dioxide from a tropical forest area from 1990 to 2001. Which statements are correct?
May/June 2021
The diagram illustrates the water cycle. Four separate processes are labelled with numbers. Which row correctly identifies the processes?
May/June 2022
The diagram illustrates part of the carbon cycle. Which process is represented by the arrows marked X?
May/June 2022
The diagram illustrates the water cycle. Four separate processes are numbered. Which row names the processes accurately?
May/June 2022
The diagram illustrates part of the carbon cycle. Which process is represented by the arrows labelled X?
May/June 2022
Researchers studied the impact of applying cattle manure (cattle faeces) to fields in which snap bean plants, Phaseolus vulgaris, were grown. Cattle manure contains some protein.
May/June 2022
A few of the processes involved in the carbon cycle are shown. In the carbon cycle, which of these processes give off carbon dioxide into the atmosphere?
May/June 2024
The carbon cycle includes these processes: combustion decomposition feeding photosynthesis respiration Of these processes, how many cause carbon dioxide to be released into the atmosphere?
May/June 2024
In the carbon cycle, which process takes in carbon dioxide?
May/June 2024
Which organisms take nitrate ions out of soil?
May/June 2024
Which diagram illustrates part of the nitrogen cycle?
May/June 2024
The diagram illustrates part of the nitrogen cycle. Which numbers indicate decomposing bacteria and nitrifying bacteria?
May/June 2024
A sequence of the different stages that take place during eutrophication is shown below. 1 reduction in dissolved oxygen 2 increase in nitrate ions 3 death of organisms requiring dissolved oxygen 4 growth of producers 5 increased aerobic respiration by decomposers 6 death of producers followed by their decomposition What is the correct sequence in which these events happen during eutrophication?
May/June 2024
The diagram illustrates part of the carbon cycle. Which two numbered arrows show respiration?
May/June 2025
The diagram illustrates part of the carbon cycle. Which process releases carbon dioxide from substances formed by photosynthesis millions of years ago?
May/June 2025
A student carried out an investigation into how a high temperature affects the formation of nitrate ions in soil. Two soil samples were used. One of the samples was heated to $100^\circ\text{C}$. All nitrate ions were then removed entirely from both samples of soil. Next, ammonium ions were added to each soil sample. After two weeks, both samples of soil were tested to find out whether nitrate ions were present. The results are shown. Which statement explains the results?
May/June 2025
The diagram illustrates part of the nitrogen cycle. What is the process marked X in the diagram?
May/June 2025
Which process in the nitrogen cycle can be brought about by lightning and bacteria?
May/June 2025
The diagram illustrates part of the carbon cycle. Which process is labelled Z?
Oct/Nov 2016
The diagram illustrates a section of the nitrogen cycle. What might be responsible for process X?
Oct/Nov 2016
When raw sewage enters a stream, what outcome can eutrophication cause?
Oct/Nov 2016
The diagram illustrates part of the nitrogen cycle. What process is $S$?
Oct/Nov 2016
The diagram illustrates a section of the carbon cycle. Which two numbered arrows indicate respiration?
Oct/Nov 2017
Plants cannot make use of nitrogen in the air until it has been converted into nitrates. Which two processes change nitrogen from the air into nitrates?
Oct/Nov 2017
The activity of what type of bacteria would result in soil being deficient in nitrates?
Oct/Nov 2017
The diagram illustrates part of the nitrogen cycle. Which row correctly names the bacteria involved in processes W, X, Y and Z?
Oct/Nov 2018
The diagram illustrates part of the nitrogen cycle. Which change results from the activity of denitrifying bacteria?
Oct/Nov 2018
A greater amount of nitrates in rivers and lakes can lead to fish dying. Which statement explains why fish die in rivers and lakes with a high nitrate concentration?
Oct/Nov 2018
The boxes on the left list the process names from the carbon cycle. The boxes on the right give some process descriptions. Draw one straight line from each process to connect it to its description. One example has already been completed for you.
Oct/Nov 2018
Fig. 1.1 presents a biomass pyramid together with a section of the carbon cycle. The diagram has these labelled parts: a box marked "CO2 in atmosphere"; four layered boxes marked A, B, C and D showing trophic levels; a box marked "decomposers"; a box marked "fossil fuels"; and arrows indicating transfers between the components. Arrow X shows movement from decomposers to CO2 in atmosphere.
Oct/Nov 2018
Which process forms part of the carbon cycle?
Oct/Nov 2019
Which process forms part of the water cycle?
Oct/Nov 2019
The diagram illustrates part of the nitrogen cycle. Which mineral ion is shown?
Oct/Nov 2019
The diagram illustrates a section of the nitrogen cycle. During which stage does denitrification take place?
Oct/Nov 2019
What might be responsible for converting nitrogen in the atmosphere into nitrates in the soil?
Oct/Nov 2019
Fig. 7.1 illustrates a section of the nitrogen cycle.
Oct/Nov 2019
Carbon dioxide makes up about 0.04% of the atmosphere. Fig. 6.1 illustrates a section of the carbon cycle.
Oct/Nov 2019
The diagram illustrates the water cycle. The table lists the processes involved in the water cycle. Which row is correct?
Oct/Nov 2021
The diagram illustrates part of the nitrogen cycle. Which processes are performed by bacteria?
Oct/Nov 2021
The diagram illustrates part of the nitrogen cycle. Which letter indicates denitrification?
Oct/Nov 2021
Carbon in the environment.
Oct/Nov 2021
State two factors that influence the volume of urine produced by the human body.
Oct/Nov 2021
The diagram illustrates part of the carbon cycle. Which processes decrease or raise the concentration of carbon dioxide in the atmosphere?
Oct/Nov 2022
The diagram illustrates a section of the water cycle. Which row names the various parts of the water cycle?
Oct/Nov 2022
The diagram illustrates part of the carbon cycle. The arrowheads have been left out of the diagram, so the direction in which carbon moves is not shown. How many arrows need to be directed towards the box labelled carbon dioxide in the atmosphere?
Oct/Nov 2022
The diagram displays a section of the nitrogen cycle. Which row gives the correct labels?
Oct/Nov 2022
The diagram illustrates the nitrogen cycle in the ocean. Which stage is nitrification?
Oct/Nov 2022
Deforestation causes the concentration of carbon dioxide in the atmosphere to rise. Which explanation is correct?
Oct/Nov 2022
The diagram illustrates a section of the nitrogen cycle. Which process in the cycle is carried out by bacterium X?
Oct/Nov 2022
The diagram illustrates a section of the carbon cycle. Which arrow shows respiration?
Oct/Nov 2023
The diagram illustrates a section of the nitrogen cycle. Which row identifies the correct processes for R, S and T?
Oct/Nov 2023
In the nitrogen cycle, which process returns nitrogen gas to the atmosphere?
Oct/Nov 2023
In which stage of the nitrogen cycle do microorganisms remove nitrogen from the atmosphere and convert it into nitrogen compounds?
Oct/Nov 2023
A rise in the concentration of nitrates in water may cause fish to die because of eutrophication. Some stages in eutrophication are shown below. 1 increased aerobic respiration by decomposers 2 increased decomposition after the death of producers 3 increased growth of producers 4 a decrease in dissolved oxygen What is the correct order of these stages leading to the death of fish?
Oct/Nov 2023
Identify the processes marked W, X, Y and Z in Fig. 8.1.
Oct/Nov 2023
Acidic soils promote a rise in anaerobic bacteria that lead to denitrification. In what way do acidic conditions influence the nitrogen cycle?
Oct/Nov 2024
Which process in the nitrogen cycle takes nitrogen gas out of the atmosphere?
Oct/Nov 2024
The flow chart shows the process of eutrophication. What should appear at step X and step Y in the flow chart?
Oct/Nov 2024