Final answer:
A female fetus develops between one to two million primary oocytes in her ovaries, which are formed from oogonia through mitosis. These primary oocytes will gradually decrease in number until menopause. Throughout a woman's reproductive life, typically, only one secondary oocyte survives the ovulation process per cycle.
Step-by-step explanation:
In foetal ovarian development, oogonia, which are ovarian stem cells, undergo mitosis to form primary oocytes. A female fetus will have between one to two million primary oocytes at birth. Throughout her life, starting at puberty, the number of these oocytes will decrease, through a process called atresia, until there are none left at menopause. Importantly, each cycle of oogenesis can produce up to four cells, but typically only one cell, the secondary oocyte, survives after the unequal cell division during meiosis where the other cells, called polar bodies, eventually disintegrate.
Folliculogenesis is the developmental process where ovarian follicles, which contain oocytes and supporting cells, grow and develop. This process leads to the ovulation of one developed follicle while other undeveloped follicles undergo atresia. It is during puberty when the primary oocytes, which have remained arrested in the first prophase stage of meiosis I since birth, resume their development, leading to the eventual release of a secondary oocyte during the ovarian cycle.