Explain why a habitat with many different species of plants and insects has greater biodiversity than a habitat with only a few species.

Eduqas GCSE Biology — 6.3 Biodiversity · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

A wildflower meadow contains over 150 species of flowering plants and more than 200 species of insects. A nearby intensively farmed field contains only 3 species of grass and fewer than 10 species of insects.

Model answer (4 marks)

Biodiversity is the variety or number of different species in a habitat.

The wildflower meadow contains over 150 species of flowering plants and more than 200 species of insects, giving it a large number of different species.

The intensively farmed field has only 3 species of grass and fewer than 10 species of insects, so it has far fewer different species.

Because the meadow has a greater variety of species, its food webs are more complex, the species are more interdependent and the ecosystem is more stable, giving it greater biodiversity than the farmed field.

Examiner tips

  • Use the definition of biodiversity first, then compare species numbers, and finish with the ecological consequences of higher diversity.
  • Show the link between many species and complex food webs, interdependence and stability.

Common mistakes

  • Confusing biodiversity with species richness only, ignoring ecosystem stability; "species richness" is a synonym but not the full definition.
  • Failing to mention the numbers of species in each habitat, or giving the wrong numbers.

Mark scheme (4 marks)

  1. Biodiversity refers to the variety/number of different species in an area/habitat
  2. The wildflower meadow has a greater number/variety of different species (of plants and insects)
  3. The farmed field has fewer different species so lower biodiversity
  4. Greater variety of species means more complex food webs / more interdependence / greater stability of the ecosystem

Key terms in this question

biodiversity · species · habitat

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