CBSE Class 10 Answered

Oogenesis refers to the process of formation, development and maturation of an ovum from oogonium though various steps (gametogenesis).

The ovary releases one egg every month. The uterus also prepares itself every month to receive a fertilized egg. The inner uterus lining becomes thick and is supplied with blood to nourish the embryo. If the egg is not fertilized, then the uterus lining is not required. Hence, it breaks down and is released in the form of blood and mucous through the vagina. This process lasts for 2-8 days. This cycle occurs every month and is known as menstruation.