OCR GCSE Biology Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success

The release of the egg from the ovary is a key event in the menstrual cycle and directly signifies ovulation. During this phase, typically occurring around the middle of the cycle, a mature follicle bursts, releasing an egg that can potentially be fertilized by sperm. This process is critical for reproduction, and its timing is regulated by hormonal changes in the female body.

The other choices represent different aspects of the menstrual cycle. The breakdown of the uterus lining happens if pregnancy does not occur and is a sign of menstruation rather than ovulation. FSH, or follicle-stimulating hormone, plays a role in the maturation of follicles and can peak prior to ovulation, but it does not indicate that ovulation has already taken place. Lastly, the menstruation phase marks the shedding of the lining when conception has not occurred, which is also not related to the event of ovulation itself. Thus, the release of the egg is the definitive indicator of ovulation.