# Explain why it can take many generations of selective breeding before a plant variety with a consistently high sugar content is produced.

> Pearson Edexcel International GCSE Biology (4BI1) — 5.2 Selective breeding · Explain · 4 marks

> Sugar beet is a crop plant grown for its high sugar content. Farmers use selective breeding to try to increase the sugar content of sugar beet plants over time.

## Mark scheme (4 marks)

1. Only plants with the highest sugar content are selected / chosen as parents for breeding
2. The selected plants are bred together / cross-pollinated to produce offspring
3. The offspring show variation in sugar content / not all offspring inherit the desirable characteristic
4. The process of selecting and breeding the highest-sugar offspring must be repeated over many generations to increase the frequency of the desirable characteristic / phenotype in the population

## Key terms

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

## Related

- [Revision notes for Pearson Edexcel International GCSE Biology (4BI1)](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-why-it-can-take-many-2cd7687a) · Published by Druglandscape Ltd.