Explain why a community with many different species of plants and animals has greater biodiversity than a community with fewer species, and describe one reason why high biodiversity is important for the stability of a community.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Scientists surveyed two woodland areas. Woodland A contained 25 different species of plants and animals. Woodland B contained 8 different species of plants and animals.
Model answer (5 marks)
Biodiversity is the variety of different species in a community.
Woodland A has greater biodiversity than Woodland B because it contains 25 species, a larger number and greater variety of species.
High biodiversity gives a community more species in the food web, creating more feeding relationships.
If one species is lost or declines, other species can use alternative food sources or prey.
Thus the community is more stable and less likely to collapse when a species is removed.
Woodland A has greater biodiversity than Woodland B because it contains 25 species, a larger number and greater variety of species.
High biodiversity gives a community more species in the food web, creating more feeding relationships.
If one species is lost or declines, other species can use alternative food sources or prey.
Thus the community is more stable and less likely to collapse when a species is removed.
Examiner tips
- Use the definition of biodiversity first, then compare species numbers; link more species to more food‑web links and stability; keep sentences short and factual.
Common mistakes
- Confusing biodiversity with species richness only; not explaining the link to stability; using vague terms like "more life" without specifying food‑web relationships.
Mark scheme (5 marks)
- Biodiversity is the variety of different species (of organisms) in an area / community
- Woodland A has greater biodiversity because it has a greater number / variety of different species
- High biodiversity means there are more species in the food web / more feeding relationships available
- If one species is lost / declines, other species can use alternative food sources / prey
- This means the community / ecosystem is more stable / less likely to collapse if one species is removed
Key terms in this question
biodiversity · community · species · stability
Related
- All AQA A-Level Biology (7402) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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