# Explain how ex situ conservation methods can complement in situ conservation in efforts to prevent the extinction of an endangered species.

> IB DP Biology Higher Level (2023 syllabus) — A4.2 Conservation of biodiversity · Explain · 4 marks

## Mark scheme (4 marks)

1. Ex situ conservation (e.g. captive breeding programmes, seed banks, botanic gardens) maintains individuals or genetic material outside their natural habitat, providing a safety net when in situ populations are critically small.
2. Ex situ programmes can maintain or increase population size / genetic diversity when in situ populations are too small to sustain themselves, reducing the risk of inbreeding depression.
3. Individuals bred or propagated ex situ can be reintroduced into restored or protected habitats, supplementing in situ populations and restoring ecological function.
4. Ex situ methods address immediate threats (e.g. disease, habitat destruction, poaching) that in situ methods cannot always control, so the two approaches together cover a wider range of extinction risks than either alone.

## Key terms

- [ex situ conservation](https://www.gradenine.co.uk/glossary/ex-situ-conservation)
- [in situ conservation](https://www.gradenine.co.uk/glossary/in-situ-conservation)

## Related

- [Revision notes for IB DP Biology Higher Level (2023 syllabus)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" 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/explain-how-ex-situ-conservation-methods-960b6af5) · Published by Druglandscape Ltd.