# A conservation organisation is comparing two freshwater lakes. Lake A contains 12 different species of invertebrate, 4 species of fish, and 3 species of aquatic plant. Lake B contains 2 species of invertebrate, 1 species of fish, and 1 species of aquatic plant. Describe what is meant by biodiversity and explain why Lake A has greater biodiversity than Lake B.

> WJEC GCSE Biology (Wales) — 2.1.2 Biodiversity · Describe · 4 marks

> A conservation organisation is comparing two freshwater lakes. Lake A contains 12 different species of invertebrate, 4 species of fish, and 3 species of aquatic plant. Lake B contains 2 species of invertebrate, 1 species of fish, and 1 species of aquatic plant.

## Mark scheme (4 marks)

1. Biodiversity is the variety / range of different species in an area / habitat / ecosystem
2. Lake A has a greater total number of different species than Lake B
3. Lake A has greater variety across more than one group of organisms (invertebrates, fish, and plants)
4. Greater biodiversity in Lake A means the ecosystem is more stable / less vulnerable to change / loss of a species has less impact

## Key terms

- [biodiversity](https://www.gradenine.co.uk/glossary/biodiversity)
- [species](https://www.gradenine.co.uk/glossary/species)

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-conservation-organisation-is-comparing-two-40b2f76d) · Published by Druglandscape Ltd.