Lesson 4.1.1

4.1.1 Biodiversity, endemism and threats to variety of life Quiz: Pearson Edexcel Biology A (Salters-Nuffield), Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.1.1, Biodiversity, endemism and threats to variety of life: 20 multiple choice questions for the Pearson Edexcel Biology A (Salters-Nuffield) (9BI0), Unit 4: Biodiversity and Natural Resources, written with Revision Ninja.

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The 20 questions

  1. What is biodiversity?

    • The number of plants found in a single tree
    • The variety of living organisms at all levels, including genetic, species and ecosystem diversity
    • The breeding success of one species in captivity
    • The total mass of all organisms in one habitat

  2. What does endemism mean?

    • A species that is found naturally in only one particular geographical area
    • A species that has become extinct in the last century
    • A species that is found across every continent
    • A species that has been introduced to an area by humans

  3. Which is a major threat to biodiversity caused by human activity?

    • Habitat loss through clearing land for agriculture and development
    • Natural succession in a mature woodland
    • Seasonal migration of birds between regions
    • Pollination of flowers by insects

  4. Why are island species often endemic?

    • Islands have stronger sunlight than the mainland
    • Species on islands always reproduce asexually
    • Isolation for long periods allows separate evolution in a limited area
    • Islands have no predators or competitors

  5. Which threat is caused by introducing non-native species into an ecosystem?

    • Competition or predation that can drive native species to decline
    • Increased rainfall that floods the habitat
    • A rise in the local level of atmospheric oxygen
    • The creation of new national parks

  6. Which factor is a major threat to species that are very specialised for a single habitat?

    • Greater genetic diversity within the species
    • An increase in the number of generalist predators
    • A rise in soil nutrient content
    • Loss or degradation of that habitat

  7. What is the term for the total variety of species in a habitat?

    • Species richness
    • Niche breadth
    • Allele frequency
    • Heterozygosity

  8. Why is biodiversity important to humans?

    • It means that only one species is needed for food production
    • It provides natural resources, such as medicines and food
    • It guarantees that climate change will not happen
    • It ensures that human populations never need to adapt

  9. Which action would most directly help conserve endangered species?

    • Introducing predators from other continents to control competitors
    • Clearing land to create more agricultural fields
    • Protecting their habitats and running captive breeding programmes
    • Removing all native plants from the area

  10. Which statement about zoos and seed banks is correct?

    • They cause all species to become extinct by removing them from the wild
    • They are used only to display animals for entertainment with no conservation role
    • They can conserve endangered species, for example by maintaining genetic stocks for future reintroduction
    • They store fossils, not living seeds or animals

  11. Which is an example of biodiversity at the genetic level?

    • Different alleles of a gene present in a population of the same species
    • The number of species in a pond
    • The number of trees in a forest
    • The variety of habitats across a country

  12. Which level of biodiversity does the number of different ecosystems in a region describe?

    • Genetic diversity
    • Ecosystem diversity
    • Allele diversity
    • Population density

  13. Why is loss of a single endemic species of conservation concern even if it is not widespread?

    • Its loss cannot be reversed and removes a unique part of the world's biodiversity
    • Endemic species never affect any other organisms
    • Loss of an endemic species always increases the biodiversity of its region
    • Endemic species are always the most abundant in their habitat

  14. Which factor is an example of pollution threatening biodiversity?

    • Seasonal leaf fall in deciduous woodland
    • Rainfall that fills a river
    • Nitrate runoff from fertiliser causing algal blooms in a lake
    • Sunlight warming the surface of a pond

  15. A forest has 60 species in one hectare, and a second forest has 20 species in the same area. Which statement is most accurate?

    • The two forests must have identical genetic diversity
    • The first forest has higher species richness than the second
    • Species richness cannot be compared between habitats
    • The second forest has higher species richness than the first

  16. What is the role of a seed bank?

    • To keep the population of an invasive plant under control
    • To sell seeds for use in commercial crop production
    • To break down seeds before they can germinate
    • To store seeds of many plant species for future conservation and restoration

  17. Why is biodiversity considered a valuable resource for humans?

    • Species are only valuable when they are used for pets
    • Species can provide new sources of drugs, materials and food that have not yet been discovered
    • Biodiversity always produces the same products in every habitat
    • Biodiversity has no value unless it is commercially farmed

  18. Which of these is a threat to biodiversity in aquatic habitats?

    • Seasonal freezing of a lake surface
    • Overfishing that reduces populations below sustainable levels
    • A rise in the number of native songbirds
    • Increased rainfall in a tropical forest

  19. Which statement about the threats to biodiversity is correct?

    • Only one threat ever affects a species at a time
    • Threats to biodiversity are always natural and cannot be prevented
    • Several threats usually act together, such as habitat loss, pollution and climate change
    • Climate change has no effect on species distributions

  20. Which term refers to a group of individuals of the same species that can interbreed in one area?

    • Ecosystem
    • Population
    • Biome
    • Community

All Pearson Edexcel Biology A (Salters-Nuffield) quizzes