# A student is investigating the menstrual cycle. Explain how the hormones oestrogen and LH work together to bring about ovulation, and describe what happens to the uterus lining in the days before ovulation occurs.

> OCR A-Level Biology B — Advancing Biology (H422) — 3.3 Reproduction, growth and development · Explain · 5 marks

> The menstrual cycle is controlled by hormones released from the pituitary gland and the ovaries. The cycle involves a series of coordinated hormonal events that prepare the body for potential pregnancy each month.

## Mark scheme (5 marks)

1. FSH stimulates the maturation of an egg in the ovary
2. Oestrogen levels rise / oestrogen is produced by the developing follicle
3. High levels of oestrogen trigger / stimulate a surge in LH
4. The surge in LH stimulates / causes ovulation (release of the egg)
5. In the days before ovulation, oestrogen causes the uterus lining to thicken / repair / build up

## Key terms

- [oestrogen](https://www.gradenine.co.uk/glossary/oestrogen)
- [ovulation](https://www.gradenine.co.uk/glossary/ovulation)
- [uterus lining](https://www.gradenine.co.uk/glossary/uterus-lining)
- [menstrual cycle](https://www.gradenine.co.uk/glossary/menstrual-cycle)

## 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)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-investigating-the-menstrual-d42a0495) · Published by Druglandscape Ltd.