when are oogonium cells produced in a female
Oogonium Oogonia are formed in large numbers by mitosis early in fetal development from primordial germ cells. In humans they start to develop between weeks 4 and 8 and are present in the fetus between weeks 5 and 30.
Zygote In human fertilization, a release ovum (a haploid secondary oocyte with replicate chromosome copies) and a haploid sperm cell (male gamete)â€”combine to form a single 2n diploid cell called the zygote. Once the single sperm enters the oocyte, it completes the division of the second meiosis forming a haploid daughter with only 23 chromosomes, almost all of the cytoplasm, and the sperm in its own pronucleus. The other product of meiosis is the second polar body with only chromosomes but no ability to replicate or survive. In the fertilized daughter, DNA is then replicated in the two separate pronuclei derived from the sperm and ovum, making the zygote's chromosome number temporarily 4n diploid. After approximately 30 hours from the time of fertilization, fusion of the pronuclei and immediate mitotic division produce two 2n diploid daughter cells called blastomeres.[2]