Ecosystems (OCR Gateway GCSE Biology)

Exam Questions

3 hours37 questions
1
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The diagram below shows a food chain

grass → locusts → snakes → eagles

If the number of snakes decreases due to disease, what will happen to the numbers of the other organisms in the food chain?

  grass locusts eagles
A increase increase increase
B increase decrease increase
C decrease decrease decrease
D decrease increase decrease

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    2
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    Which of the following factors does NOT affect the rate of decomposition of biological material within an ecosystem?

    • Availability of oxygen

    • Presence of predators nearby

    • Temperature

    • Availability of water

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    3
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    The diagram below illustrates part of the carbon cycle.

    image-1

    Which process is shown by the arrow labelled Y?

    • Photosynthesis

    • Feeding

    • Respiration

    • Combustion

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    4
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    Which of the following options shows four ecological terms in a logical order, starting with the smallest and ending with the largest?

    • individual → community → population → ecosystem

    • population → individual → ecosystem → community

    • community → population → ecosystem → individual

    • individual → population → community → ecosystem

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    5
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    Which of the following diagrams shows a pyramid of biomass for a marine ecosystem?

    image-9

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      6
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      There are different levels of organisation within an ecosystem.

      What is the correct order of these levels?

      • individual, community, population, ecosystem

      • community, individual, ecosystem, population

      • individual, population, community, ecosystem

      • population, community, ecosystem, individual

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      7
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      Look at the information about a food chain.

      Organism Number Biomass
      Oak tree 1 500,000
      Aphids 10,000 1,000
      Ladybirds 200 50


      Calculate the percentage biomass of the aphids transferred to the ladybirds.

      • 0.05%

      • 20%

      • 5%

      • 2000%

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      8
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      The diagram shows a food web.q3-paper2f-spec2018-ocrgcsebio

      What is the most likely effect on the food web, if the number of cod decreases?

      • An increase in the number of herrings

      • An increase in the number of krill

      • An increase in the number of sharks

      • No effect on the population of puffins

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      9
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      Look at the pyramid of biomass.

      q4-paper2f-spec2018-ocrgcsebio
      What can you tell from this pyramid of biomass?

      • All four trophic levels contain consumers.

      • Fleas are producers.

      • The trophic level with oak trees has the lowest biomass.

      • There are fewer birds than caterpillars.

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      10
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      Organisms in an ecosystem are affected by biotic factors.

      Which term is a biotic factor?

      • Disease

      • Light intensity

      • Rainfall

      • Wind speed

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      11
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      In food chains, biomass is lost between different trophic levels.

      One reason for this is the release of undigested food from the body.

      Which term is used to describe this release?

      • Decomposition

      • Egestion

      • Excretion

      • Peristalsis

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      12
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      Which of these is an abiotic factor that can affect organisms?

      • Food availability

      • Light intensity

      • Pathogens

      • Predators

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      13
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      The diagram shows the water cycle.q2-paper2f-june2019-ocrgcsebio

      Which label, A, B, C or D, represents evaporation?

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        14
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        Which relationship describes an organism living on an animal and harming it?

        • Decomposition

        • Mutualism

        • Parasitism

        • Predation

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        15
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        Most food chains only have a maximum of five trophic levels.

        Explain why.

        • Organisms always get larger at higher trophic levels.

        • Energy is lost at each trophic level.

        • It is more energy efficient to eat meat than plant material.

        • The number of organisms feeding always increases at higher trophic levels.

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        16
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        Which process in the carbon cycle takes in carbon dioxide from the air?

        • Combustion

        • Decomposition

        • Photosynthesis

        • Respiration

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        17
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        The diagram shows a pyramid of biomass.

        q2-paper2f-june2018-ocrgcsebio

        Which trophic level is X?

        • Primary consumers

        • Producers

        • Secondary consumers

        • Tertiary consumers

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        18
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        Which is the correct definition of a parasite?

        • An organism that is always at the top of a food chain.

        • An organism that kills and eats another organism.

        • An organism that lives on another living organism so that they both benefit.

        • An organism that lives on or in another living organism causing it harm.

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        19
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        The diagram shows a food web in the sea.

        q4-paper2h-nov2020-ocrgcsebio

        The number of penguins decreased in the area. This caused an increase in seal numbers.

        What is a possible reason for the increase in seal numbers?

        • Fewer seals were eaten.

        • The krill numbers dropped.

        • There were more plankton for the seals to eat.

        • The seals had less competition for squid.

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        20
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        The diagram shows pyramids of biomass for two food webs, X and Y.

        q14-paper2h-nov2020-ocrgcsebio

        Which statement explains the difference between the two pyramids?

        • In food web X there is a greater efficiency of transfer between primary consumer and secondary consumer than in Y.

        • In food web X there is a greater efficiency of transfer between secondary consumer and tertiary consumer than in Y.

        • In food web X there is a lower efficiency of transfer between primary consumer and secondary consumer than in Y.

        • In food web X there is a lower efficiency of transfer between secondary consumer and tertiary consumer than in Y.

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        21
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        The diagram shows part of a cycle in an ecosystem.

        q1-paper2f-nov2020-ocrgcsebio

        What is the name of the cycle shown in the diagram?

        • Carbon cycle

        • Hydrogen cycle

        • Nitrogen cycle

        • Sulfur cycle

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        22
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        Goldfish are a species of fish.

        What name is given to all the goldfish living in a pond?

        • A community

        • An ecosystem

        • A habitat

        • A population

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        23
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        This is a food chain for organisms in a forest.

        Oak tree Greenfly Ladybird Blackbird

        Which is the correct shape for a pyramid of biomass for this food chain?

        q4-paper2f-nov2020-ocrgcsebio

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