# Explain how habitat fragmentation reduces biodiversity in a population of large mammals.

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

## Mark scheme (4 marks)

1. Fragmentation isolates subpopulations, reducing gene flow between them
2. Small isolated subpopulations are more vulnerable to genetic drift, reducing genetic diversity
3. Inbreeding increases the frequency of homozygosity, leading to expression of deleterious recessive alleles (inbreeding depression)
4. Reduced population size and genetic diversity lowers the ability of the population to adapt to environmental change, increasing extinction risk

## Key terms

- [habitat fragmentation](https://www.gradenine.co.uk/glossary/habitat-fragmentation)

## Related

- [Revision notes for IB DP Biology Standard 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-habitat-fragmentation-reduces-biodiversity-a1f9e049) · Published by Druglandscape Ltd.