# A coral reef is an ecosystem where clownfish live among the tentacles of sea anemones. The anemone's stinging tentacles protect the clownfish from predators, whilst the clownfish chases away fish that would otherwise eat the anemone. Describe the relationship between the clownfish and the sea anemone, and explain how the removal of all clownfish from the reef could affect the sea anemone population.

> OCR GCSE Biology A: Gateway Science (J247) — B4.1 Ecosystems · Describe · 4 marks

> A coral reef is an ecosystem where clownfish live among the tentacles of sea anemones. The anemone's stinging tentacles protect the clownfish from predators, whilst the clownfish chases away fish that would otherwise eat the anemone.

## Mark scheme (4 marks)

1. The relationship between clownfish and sea anemone is mutualism
2. Both organisms benefit from the relationship / clownfish gains protection and anemone gains protection from its predators
3. Without clownfish, the fish that eat sea anemones would no longer be chased away / the anemone's predators would increase in number
4. The sea anemone population would decrease / sea anemones would be eaten in greater numbers and their population would fall

## Key terms

- [ecosystem](https://www.gradenine.co.uk/glossary/ecosystem)
- [population](https://www.gradenine.co.uk/glossary/population)

## Related

- [Revision notes for OCR GCSE Biology A: Gateway Science (J247)](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-coral-reef-is-an-ecosystem-6bda5236) · Published by Druglandscape Ltd.