Researchers tested three coatings for tablets used as a combined oral contraceptive. Each tablet contained the same amounts of oestrogen and progesterone. The coating affected how much of the hormones entered the blood.
The table shows the results after participants had taken the tablets for 28 days.
| Tablet coating | Concentration of contraceptive hormones in the blood as a percentage of the intended concentration (%) | Participants in whom an egg began to mature (%) |
|---|---|---|
| P | 94 | 3 |
| Q | 61 | 18 |
| R | 27 | 44 |
Explain which tablet coating would produce the least effective contraceptive. Use the data in the table and your knowledge of hormonal control.
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.