Lesson 4.7.3.1

4.7.3.1 Biodiversity Quiz: AQA Biology, Unit 7

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 4.7.3.1, Biodiversity: 20 multiple choice questions for the AQA GCSE Biology (8461), Unit 7: Ecology, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What term describes the variety of all different species of organisms in an ecosystem?

    • Bioaccumulation
    • Eutrophication
    • Biodiversity
    • Biomass

  2. How does high biodiversity increase the stability of an ecosystem?

    • Decreases gene pools
    • Increases species competition
    • Eliminates all predators
    • Reduces species dependence

  3. What must humans maintain to ensure the future survival of our species?

    • High carbon emissions
    • High waste production
    • High deforestation
    • High biodiversity

  4. Which measurement best indicates the biodiversity of an ecosystem?

    • Land surface area
    • Species count
    • Total organism mass
    • Individual population size

  5. What have humans recently introduced to combat the reduction in global biodiversity?

    • Increased waste dumping
    • Conservation measures
    • Habitat destruction
    • Industrial deforestation

  6. Biodiversity can be measured within a single ecosystem or across what wider area?

    • One food chain
    • One population only
    • A single organism
    • The whole Earth

  7. What is the overall effect of many human activities on global biodiversity?

    • Maintains biodiversity
    • Increases biodiversity
    • Has no effect
    • Reduces biodiversity

  8. What factor directly ensures the overall stability of an ecosystem?

    • Small population
    • High biodiversity
    • High biomass
    • Low biodiversity

  9. Ecosystem X has 15 total species and Ecosystem Y has 4. Which has higher biodiversity?

    • Both are equal
    • Ecosystem X
    • Ecosystem Y
    • Neither ecosystem

  10. What happens to biodiversity when a forest loses most of its tree species?

    • It increases
    • It doubles
    • It decreases
    • It stays constant

  11. Which ecosystem is usually more stable?

    • Many species present
    • No species present
    • One species present
    • Two species present

  12. Which pollutant in water kills aquatic organisms and reduces biodiversity?

    • Untreated sewage
    • Plant compost
    • Carbon dioxide
    • Dissolved oxygen

  13. Two woodlands have 30 and 12 species respectively. How many more species does the first have?

    • 12
    • 18
    • 42
    • 2.5

  14. Which ecosystem remains more stable if one food source fails?

    • No species
    • Single species
    • Low biodiversity
    • High biodiversity

  15. High biodiversity reduces the dependence of one species on another for what?

    • Light and heat
    • Food and shelter
    • Soil and rock
    • Gravity and radiation

  16. What aspect of an ecosystem does high plant diversity help to maintain?

    • Solar radiation
    • Tidal movement
    • Atmospheric pressure
    • Physical environment

  17. Why is a 10-species forest more stable than a 2-species forest?

    • Fewer producers
    • Higher temperature
    • Less solar energy
    • More alternative species

  18. Why does removing one species cause greater instability in low-biodiversity ecosystems?

    • Fewer species alternatives
    • Greater genetic variation
    • Faster reproduction rates
    • Higher producer numbers

  19. What effect do combined human activities generally have on natural habitats?

    • Neutral impact
    • Increased biodiversity
    • Constant biodiversity
    • Reduced biodiversity

  20. Which greenhouse gas is released in large quantities by deforestation and fossil fuel combustion?

    • Nitrogen
    • Oxygen
    • Carbon dioxide
    • Hydrogen

All AQA Biology quizzes