Describe the roles of oestrogen and progesterone in the menstrual cycle.

Pearson Edexcel International GCSE Biology (4BI1) — 3.1 Reproduction · Describe · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Oestrogen, produced by the ovaries, stimulates growth and repair of the uterine lining during the follicular phase.
Progesterone, also released by the ovaries, maintains the uterine lining after ovulation.
If fertilisation does not occur, progesterone falls, the lining breaks down and menstruation occurs.

Examiner tips

Use the word ‘produced’ for oestrogen and ‘released’ for progesterone to match the scheme.
Mention the follicular and luteal phases to show understanding of timing.
Show the cause–effect link: oestrogen → lining growth, progesterone → maintenance, fall → menstruation.

Common mistakes

Confusing the roles of oestrogen and progesterone, e.g. saying progesterone causes growth of the lining.
Omitting that oestrogen is produced by the ovaries or that progesterone is released by the ovaries.
Failing to mention the fall in progesterone leading to menstruation.

Mark scheme (4 marks)

Oestrogen causes the growth and repair of the uterus lining
Oestrogen is released / produced by the ovaries
Progesterone maintains the uterus lining
If fertilisation does not occur, progesterone levels fall, causing the uterus lining to break down / menstruation to occur

Key terms in this question

oestrogen · progesterone · menstrual cycle