IGCSE Biology – Human Reproduction Practice Test

Hormonal control plays a critical role in the menstrual cycle, primarily by regulating the processes of egg maturation and the preparation of the uterine lining for potential pregnancy. The menstrual cycle is governed by a complex interplay of hormones such as estrogen and progesterone, which are secreted by the ovaries in response to signals from the pituitary gland.

During the first phase of the menstrual cycle, known as the follicular phase, follicle-stimulating hormone (FSH) stimulates the growth and maturation of ovarian follicles. As these follicles develop, they produce estrogen, which helps thicken the endometrium (the lining of the uterus) in preparation for a possible implantation of a fertilized egg.

Then, around the midpoint of the cycle, typically around day 14 in a 28-day cycle, a surge in luteinizing hormone (LH) triggers ovulation, leading to the release of a mature egg. Following ovulation, the luteal phase begins, during which the ruptured follicle transforms into the corpus luteum, producing progesterone. This hormone continues to prepare the uterine lining, making it receptive for a fertilized egg. If fertilization does not occur, levels of estrogen and progesterone decline, leading to the shedding