28-16
Before Birth
nThe process of oogenesis
occurs in a female fetus before birth. At this time, the ovary contains primordial germ cells called oogonia, which are diploid cells, meaning they have 23
pairs of chromosomes.
nDuring the fetal period,
the oogonia start the process of meiosis, but they are stopped at prophase I. At this point, the cells are called primary oocytes.
nAt birth, the ovary of a
female child is estimated to contain approximately
1.5 to 2
million primordial follicles within its cortex.
nThe primary oocytes in
the primordial follicles remain arrested in prophase I until after puberty.