# Describe the importance of biodiversity and explain how human activities can threaten it. In your answer, refer to the impact on ecosystems.

> Pearson Edexcel A-Level Biology A (9BI0) — 2.5 Biodiversity · Describe · 5 marks

> Scientists estimate that human activity has caused species extinction rates to rise to more than 1000 times the natural background rate. Many conservation organisations argue that protecting biodiversity should be a global priority.

## Mark scheme (5 marks)

1. Biodiversity refers to the variety of living organisms / species in an area (or on Earth)
2. Greater biodiversity makes ecosystems more stable / resilient to change
3. Human activity such as deforestation / habitat destruction / pollution / climate change reduces biodiversity
4. Loss of one species can affect others in the ecosystem, e.g. disrupting food chains / webs
5. Reduced biodiversity can reduce the stability of an ecosystem making it less able to recover from change / more vulnerable to collapse

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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/describe-the-importance-of-biodiversity-and-c1f06759) · Published by Druglandscape Ltd.