Doctors monitored one menstrual cycle in a patient. The table shows measurements made using blood tests and ultrasound scans.
| Day of cycle | LH concentration in blood in IU L⁻¹ | Diameter of largest ovarian follicle in mm | Follicle observation | Thickness of uterus lining in mm |
|---|---|---|---|---|
| 5 | 4 | 7 | developing | 3 |
| 13 | 38 | 20 | fully developed | 7 |
| 16 | 5 | 20 | unruptured; egg not released | 9 |
Explain, using the data, why FSH and oestrogen appear to have acted normally but LH did not have its usual effect.
Explain how the progesterone concentration and the uterus lining are likely to change after day 16.
90 exam-style questions on Edexcel GCSE Biology 7.2 Reproductive hormones, covering 7.2.1 Stages of the menstrual cycle, 7.2.2 Hormonal control of the menstrual cycle, 7.2.3 Hormonal contraception, 7.2.4 Evaluating contraception methods, and 7.2.5 Hormones in Assisted Reproductive Technology. Each one has a worked solution and a mark scheme showing where the marks go.