Reproduction In Vertebrates - SS2 Biology Past Questions and Answers - page 3

Ova, or eggs, are produced in the ovaries through a process called oogenesis. Oogenesis begins during fetal development, where primordial germ cells differentiate into oogonia. Oogonia undergo mitotic divisions to form primary oocytes. During each menstrual cycle, a small number of primary oocytes are activated and progress through meiosis I, resulting in the formation of a secondary oocyte and a polar body. Meiosis II occurs upon fertilization, producing the mature ovum and another polar body.