# Explain how the structure of xylem vessels and phloem vessels are each adapted to carry out their specific transport roles in a plant.

> Eduqas A-Level Biology — 2.4 Adaptations for nutrition · Explain · 5 marks

> Plants have two main types of transport vessel — xylem and phloem — which move different substances around the plant.

## Mark scheme (5 marks)

1. Xylem vessels are made from hollowed-out dead cells / have no living cell contents
2. The end walls of xylem cells are removed, forming a continuous tube that allows water to flow through
3. Xylem cells are impermeable to water, preventing water from leaking out as it travels up the plant
4. Phloem is made of living cells / sieve tubes with no nuclei connected via their cytoplasm, allowing sugars to be transported
5. Companion cells supply energy to phloem sieve tubes to support the active transport of sugars in translocation

## Key terms

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

## Related

- [Revision notes for Eduqas A-Level Biology](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-xylem-c0bda98a) · Published by Druglandscape Ltd.