# A pea plant produces both male gametes and female gametes. Explain how fertilisation in this flowering plant differs from fertilisation in a mammal, and why the offspring produced by each organism are genetically different from both parents.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 2.3 Sexual reproduction in animals and plants · Explain · 5 marks

> Flowering plants and mammals both reproduce sexually, but the process of fertilisation differs between these groups. In both cases, gametes are haploid cells that are formed by meiosis.

## Mark scheme (5 marks)

1. In the pea plant, fertilisation is external to the parent body / occurs inside the ovule/ovary of the flower, whereas in a mammal fertilisation is internal (inside the female's body/reproductive tract).
2. In the plant, the male gamete (in pollen) travels to the female gamete (in the ovule) via a pollen tube, whereas in the mammal sperm swim to the egg / travel through the female reproductive tract.
3. Gametes are haploid / contain half the normal number of chromosomes, formed by meiosis.
4. At fertilisation, a male gamete fuses with a female gamete to form a diploid zygote / restoring the full chromosome number.
5. Offspring are genetically different from both parents because meiosis produces genetic variation (through independent assortment / crossing over), so each gamete has a unique combination of chromosomes/alleles, and fertilisation combines two different sets of genetic information.

## Key terms

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

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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-pea-plant-produces-both-male-ce85542f) · Published by Druglandscape Ltd.