Lesson 3.4.6.1

3.4.6.1 Biodiversity and the index of diversity Quiz: AQA Biology, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 3.4.6.1, Biodiversity and the index of diversity: 20 multiple choice questions for the AQA Biology (7402), Unit 4: Genetic information, variation and relationships, written with Revision Ninja.

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The 20 questions

  1. What is species richness?

    • The number of different species in a community
    • The proportion of a habitat covered by one species
    • The number of individuals of the most common species in a community
    • The total mass of organisms in a habitat

  2. What does an index of diversity describe?

    • The mean height of plants in a community
    • The rate of photosynthesis in a leaf
    • The relationship between the number of species and the number of individuals in each species
    • The temperature range of a habitat

  3. In the index of diversity formula d = N(N-1)/sum n(n-1), what does N represent?

    • The total number of organisms of all species
    • The number of organisms of one species
    • The number of species present
    • The number of sampling quadrats used

  4. In the index of diversity formula d = N(N-1)/sum n(n-1), what does n represent?

    • The total number of organisms of all species
    • The number of species in the community
    • The total number of organisms of each species
    • The number of quadrats placed randomly

  5. A community has 10 individuals, all of one species. What is its index of diversity?

    • 90
    • 10
    • 1
    • 0

  6. Which factor is most likely to reduce biodiversity in a habitat?

    • Diverse plant communities in woodland
    • Farming techniques that replace varied habitats with a single crop
    • Increased number of species of insects in hedgerows
    • Greater variety of microhabitats in a pond

  7. Biodiversity can be considered at different scales. Which range is included in the specification?

    • From a small local habitat to the whole Earth
    • Only in tropical rainforests
    • Only within a single species
    • Only within a single genus

  8. A community has 30 individuals in 3 species of 10 each. Calculate the index of diversity to two decimal places.

    • 9.00
    • 3.00
    • 0.33
    • 3.22

  9. Community X has 30 individuals in 3 equal species. Community Y has 30 individuals in species of 27, 2 and 1. Which index is higher and why?

    • Y, because it has more individuals of the rare species
    • X, because it has fewer total individuals to count
    • X, because its individuals are shared more evenly across species
    • Y, because one species dominates it

  10. A community has 8 individuals: 4 of species P and 4 of species Q. What is the index of diversity?

    • 4.00
    • 2.00
    • 2.33
    • 8.00

  11. A community has 10 of species A, 5 of species B and 5 of species C. What is the total number of organisms N?

    • 10
    • 20
    • 15
    • 130

  12. Why might a quadrat sample give a different species richness from the whole habitat?

    • Species richness can only be measured in a laboratory
    • Quadrats always include every species present
    • Quadrats only measure the abiotic factors in the habitat
    • A sample can miss rare species that are not in the quadrats

  13. A farmer converts a species-rich meadow into a field of one wheat variety. What is the most likely effect on the index of diversity?

    • It rises because the crop is uniform
    • It rises because the field now has more individuals
    • It stays the same because the number of plants is unchanged
    • It falls because fewer species now share the area

  14. Which sample of 20 organisms would give the highest index of diversity?

    • One species with 20 organisms
    • Two species with 10 organisms each
    • Four species with 5 organisms each
    • Ten species with 2 organisms each

  15. What balance must be considered when managing land for farming and biodiversity?

    • Maximising the number of individuals of one species
    • Replacing all native species with crops
    • Conservation of species against the need to produce food
    • Ignoring habitat boundaries

  16. An index of diversity value of 1 suggests what about a community?

    • Only one species is present
    • The community has no individuals
    • Every species has the same number of individuals
    • Maximum diversity

  17. Which statement best explains why a diversity index is more informative than species richness alone?

    • It identifies the genus of each species
    • It takes account of how evenly individuals are spread across species
    • It measures genetic variation within a species
    • It counts species without regard to their abundance

  18. Which statement about species richness and the index of diversity is correct?

    • Two communities with the same richness always have the same index value
    • Two communities can have the same richness but different index values if their individuals are distributed differently
    • The index of diversity is always equal to the species richness
    • Species richness takes account of how many individuals each species has

  19. A community has 6 individuals of species A and 2 of species B. What is the index of diversity to two decimal places?

    • 0.75
    • 1.75
    • 3.50
    • 2.33

  20. What does the index of diversity formula use from the counts?

    • The area of each species' habitat
    • The mass of each individual organism
    • The number of individuals in each species and the total number of individuals
    • The number of quadrats used in the survey only

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