# A scientist is investigating sexual reproduction in flowering plants. Explain how fertilisation occurs in a flowering plant and why the offspring produced by sexual reproduction show genetic variation.

> Pearson Edexcel A-Level Biology A (9BI0) — Topic 2 Cells, Viruses and Reproduction · Explain · 5 marks

> Flowering plants reproduce sexually. During this process, male and female gametes are produced and must combine to form a new organism.

## Mark scheme (5 marks)

1. Pollen (containing the male gamete) is transferred to the stigma (pollination)
2. The male gamete (nucleus) travels through the pollen tube to reach the female gamete (in the ovule)
3. Fertilisation is the fusion of the male and female gametes (nuclei)
4. Gametes are formed by meiosis, producing cells with half the normal chromosome number (haploid)
5. Meiosis produces gametes with different combinations of chromosomes / alleles, so offspring inherit a unique mix of genetic information from both parents, leading to genetic variation

## Key terms

- [fertilisation](https://www.gradenine.co.uk/glossary/fertilisation)
- [genetic variation](https://www.gradenine.co.uk/glossary/genetic-variation)

## Related

- [Revision notes for Pearson Edexcel A-Level Biology A (9BI0)](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-scientist-is-investigating-sexual-reproduction-fe0454dc) · Published by Druglandscape Ltd.