# Explain how the structural adaptations of a xerophyte reduce water loss.

> IB DP Biology Standard Level (2023 syllabus) — B4.1 Adaptation to environment · Explain · 4 marks

> Xerophytes are plants adapted to survive in environments where water availability is extremely limited, such as deserts or exposed rocky habitats.

## Mark scheme (4 marks)

1. Thick, waxy cuticle reduces evaporation of water from the leaf surface
2. Stomata are sunken in pits or grooves, which trap humid air and reduce the water vapour concentration gradient, decreasing the rate of transpiration
3. Leaves are reduced in size or modified into spines/needles, decreasing the surface area available for transpiration
4. Leaves may roll or curl, enclosing the stomata in a humid microenvironment, which reduces the water vapour concentration gradient and therefore the rate of transpiration

## Key terms

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

## 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)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-structural-adaptations-of-277e8b88) · Published by Druglandscape Ltd.