# Explain how the structure of the xylem is adapted to transport water from the roots to the leaves of a plant.

> WJEC A-Level Biology (Wales) — 2.4 Adaptations for nutrition · Explain · 5 marks

> Plants need to move water from the soil, through the roots, up the stem and into the leaves where it is used in photosynthesis. This transport is carried out by the xylem.

## Mark scheme (5 marks)

1. Xylem vessels are made from hollowed-out dead cells / have no cell contents
2. The end walls between cells are removed / broken down, forming a continuous tube
3. This allows water to pass through without obstruction / allows continuous uninterrupted flow of water
4. The walls of the xylem are impermeable to water / strengthened with lignin
5. Impermeability / lignin ensures water is directed upwards rather than leaking sideways into surrounding tissue

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-the-structure-of-the-341f98c1) · Published by Druglandscape Ltd.