Ace IGCSE Biology 2025: Demystify Human Reproduction with Our Dynamic Practice Test!

When fertilization does not occur, the corpus luteum, which is the structure formed from the follicle after ovulation, degenerates. This degeneration leads to a decrease in levels of hormones such as progesterone and estrogen that the corpus luteum produces. The drop in these hormone levels signals the uterus to shed its lining, resulting in menstruation. This is a key part of the menstrual cycle, where the body prepares for a potential pregnancy each month. If no pregnancy occurs, the cycle resets, and menstruation is the visible sign that the body is ready to start anew.

The other options presented are not accurate representations of what occurs if fertilization does not happen. The egg does not stay viable for another cycle but typically disintegrates or is absorbed if not fertilized. The menstrual cycle does not halt but continues, initiating menstruation as a response to the hormonal changes. The ovary does not produce sperm at any point in the female reproductive cycle, as sperm production is a function of the male reproductive system.