An electronic model represents feedback control during the first half of the menstrual cycle. The model uses the oestrogen concentration as an input and displays the expected release of FSH and LH from the pituitary gland. The model is programmed so that both FSH and LH decrease whenever oestrogen increases.
Which change to the model would make its output consistent with hormonal control of the menstrual cycle?
Make FSH increase as oestrogen rises, but keep LH decreasing when the oestrogen concentration becomes high.
Keep both FSH and LH decreasing until the oestrogen concentration begins to fall.
Make both FSH and LH increase steadily whenever the oestrogen concentration increases.
Keep FSH decreasing as oestrogen rises, but make LH increase sharply when the oestrogen concentration becomes high.
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.