# Explain how the structure of xylem vessels is adapted for the transport of water through a plant.

> WJEC A-Level Biology (Wales) — 2.3 Adaptations for transport in plants and animals · Explain · 5 marks

> Plants need to move water from their roots up to their leaves, where it is used in photosynthesis. This transport occurs through xylem vessels.

## Mark scheme (5 marks)

1. Xylem vessels are made from hollowed-out dead cells / have no cell contents
2. The end walls of the cells are removed / broken down to form a continuous tube
3. This allows water to flow freely / continuously from roots to leaves
4. The walls are strengthened with lignin to prevent the vessel from collapsing under pressure
5. The walls are impermeable to water so water is directed upwards rather than leaking out through the sides

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Biology (Wales)](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-the-structure-of-xylem-e78a91fb) · Published by Druglandscape Ltd.