Ans. The menstrual cycle is a monthly series of changes that occur in the female reproductive system. It involves the development and release of an egg from the ovaries, as well as the thickening of the uterine lining in preparation for a possible pregnancy. If fertilization does not occur, the uterine lining is shed during menstruation.The menstrual cycle is important in the female reproductive system because it allows for the regular release of mature eggs, which can be fertilized by sperm to initiate pregnancy. It also helps prepare the uterus for the implantation of a fertilized egg. Additionally, the menstrual cycle provides insights into the overall health of the reproductive system.