# A salmon is a vertebrate animal that reproduces sexually. During sexual reproduction, gametes are produced by meiosis and then fuse during fertilisation. Explain why the offspring produced by sexual reproduction in salmon are not genetically identical to one another.

> Pearson Edexcel A-Level Biology A (9BI0) — 2.3 Sexual reproduction in animals and plants · Explain · 5 marks

> Salmon reproduce sexually. Each female salmon can release thousands of eggs into the water, where they are fertilised by sperm from a male salmon. The fertilised eggs develop into new salmon.

## Mark scheme (5 marks)

1. Gametes are haploid / contain only one copy of each chromosome
2. Meiosis produces genetic variation / gametes are not genetically identical to each other
3. Fertilisation is random / any egg can be fertilised by any sperm
4. The zygote / fertilised egg receives chromosomes from both parents
5. Different combinations of chromosomes / alleles are passed to each offspring, producing genetic variation

## Key terms

- [gametes](https://www.gradenine.co.uk/glossary/gametes)
- [meiosis](https://www.gradenine.co.uk/glossary/meiosis)
- [fertilisation](https://www.gradenine.co.uk/glossary/fertilisation)

## 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-salmon-is-a-vertebrate-animal-16f73f02) · Published by Druglandscape Ltd.