During the menstrual cycle, coordination between the ovaries and the pituitary gland relies on both negative and positive feedback loops. Mid-cycle, a rapid increase in the concentration of an ovarian hormone triggers a positive feedback mechanism.
Which hormone directly triggers ovulation, and which ovarian hormone is responsible for initiating this positive feedback surge?
Triggering hormone: Luteinising Hormone (LH); Ovarian feedback hormone: Oestrogen
Triggering hormone: Follicle Stimulating Hormone (FSH); Ovarian feedback hormone: Oestrogen
Triggering hormone: Luteinising Hormone (LH); Ovarian feedback hormone: Progesterone
Triggering hormone: Progesterone; Ovarian feedback hormone: Luteinising Hormone (LH)
23 exam-style questions on OCR GCSE Biology 3.2 Coordination and control – the endocrine system, covering 3.2.1 Principles of hormonal coordination and control, 3.2.2 Roles of thyroxine and adrenaline, 3.2.3 Hormones in human reproduction, 3.2.4 Interactions of reproductive hormones, 3.2.5 Hormones in contraception, 3.2.6 Hormones in reproductive technologies, 3.2.7 Plant hormones in growth and coordination, 3.2.8 Effects of plant hormones, and 3.2.9 Uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.