Explain why a habitat with a large number of different species is considered to have high biodiversity.

Eduqas GCSE Biology — 2.1.2 Biodiversity · Explain · 4 marks · View as Markdown

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

Model answer (4 marks)

Biodiversity is the variety of species in a habitat. A habitat with many different species has a greater range of organisms, so it shows high biodiversity. This variety makes the ecosystem more stable and less vulnerable to change. If one species disappears, other species can take over its role, so the food web is less affected.

Examiner tips

Use the definition of biodiversity first, then link variety to stability and resilience.
Show the chain: many species → variety → stability → redundancy in roles.
Mention that loss of one species is less damaging in a diverse system.

Common mistakes

Confusing biodiversity with population size of a single species.
Failing to explain how variety leads to stability.
Using vague terms like "many" without linking to ecosystem function.

Mark scheme (4 marks)

Biodiversity refers to the variety/range of different species in an area/habitat
A greater number of different species means there is greater variety
High biodiversity means the ecosystem/habitat is more stable / less vulnerable to change
If one species is lost / becomes extinct, other species can fulfil similar roles / food web is less affected

Key terms in this question

biodiversity · species · habitat