# A potato plant stores starch in its underground tubers during summer. Explain how sucrose produced in the leaves reaches the tubers, naming the tissue involved and the direction of movement.

> Cambridge International IGCSE Biology (0610) — 8.4 Translocation · Explain · 4 marks

## Mark scheme (4 marks)

1. Sucrose is produced / made in the leaves, which act as the source
2. Sucrose is transported through the phloem
3. Movement is from source (leaves) to sink (tubers / roots), i.e. downwards
4. The tubers are the sink because sucrose is stored / used there (converted to starch for storage)

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Biology (0610)](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/a-potato-plant-stores-starch-in-e46c85b4) · Published by Druglandscape Ltd.