# Explain how the rate of transpiration in a plant would change on a hot, sunny, windy day compared with a cool, calm, cloudy day.

> Edexcel GCSE Biology (1BI0) — 6.2 Transport in plants · Explain · 4 marks

> Transpiration is the loss of water from plant leaves and shoots via diffusion and evaporation. Several environmental factors affect how quickly this process occurs.

## Mark scheme (4 marks)

1. The rate of transpiration would be higher / faster on the hot, sunny, windy day
2. Higher temperature increases the rate of evaporation / diffusion of water molecules from the leaf
3. Greater light intensity causes stomata to open wider (guard cells become turgid), allowing more water vapour to escape
4. Wind / air flow removes water vapour from around the leaf, maintaining a steep concentration gradient so diffusion of water out of the leaf is faster

## Key terms

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

## Related

- [Revision notes for Edexcel GCSE Biology (1BI0)](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-the-rate-of-transpiration-4dd2e6df) · Published by Druglandscape Ltd.