A scientist measured the concentration of progesterone in a person's blood during a menstrual cycle.
In a usual cycle, progesterone peaks at about day 21 and falls near day 28 if there is no pregnancy.
| Day of cycle | Progesterone concentration in blood in nmol dm⁻³ |
|---|---|
| 21 | 36 |
| 23 | 9 |
| 25 | 3 |
Use the data to explain the likely effects after day 23 on the uterus lining and on the development of an egg.
85 exam-style questions on AQA GCSE Biology 5.3 Hormonal coordination in humans, covering 5.3.1 Human endocrine system, 5.3.2 Control of blood glucose concentration, 5.3.3 Maintaining water and nitrogen balance in the body, 5.3.4 Hormones in human reproduction, 5.3.5 Contraception, 5.3.6 The use of hormones to treat infertility (HT only), and 5.3.7 Negative feedback (HT only). Each one has a worked solution and a mark scheme showing where the marks go.