# A woman is trying to become pregnant. Her doctor explains that hormones control the monthly release of an egg from her ovaries. Explain how hormones in the menstrual cycle bring about ovulation and how this links to the role of gametes in reproduction.

> OCR A-Level Biology B — Advancing Biology (H422) — 5.8 Hormonal communication · Explain · 5 marks

> Hormones released by the pituitary gland and ovaries control the menstrual cycle. One key event in the cycle is ovulation — the release of an egg from the ovary. Without ovulation, fertilisation cannot occur.

## Mark scheme (5 marks)

1. A hormone (FSH) is released from the pituitary gland / a gland in the brain
2. FSH stimulates the ovary to produce oestrogen / stimulates a follicle to develop in the ovary
3. A surge in LH (luteinising hormone) triggers ovulation / causes the egg to be released from the ovary
4. The egg released is a gamete / the egg is haploid / the egg contains half the number of chromosomes
5. Fertilisation involves fusion of the egg gamete with a sperm gamete / fertilisation restores the diploid chromosome number / a zygote is formed with a full set of chromosomes

## Key terms

- [hormone](https://www.gradenine.co.uk/glossary/hormone)
- [ovulation](https://www.gradenine.co.uk/glossary/ovulation)
- [gamete](https://www.gradenine.co.uk/glossary/gamete)

## Related

- [Revision notes for OCR A-Level Biology B — Advancing Biology (H422)](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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/a-woman-is-trying-to-become-76b44361) · Published by Druglandscape Ltd.