<Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> An oocyte (UK: / ˈoʊəsaɪt /, US: / ˈoʊoʊ - /), oöcyte, ovocyte, or rarely ocyte, is a female gametocyte or germ cell involved in reproduction . In other words, it is an immature ovum, or egg cell . An oocyte is produced in the ovary during female gametogenesis . The female germ cells produce a primordial germ cell (PGC), which then undergoes mitosis, forming oogonia . During oogenesis, the oogonia become primary oocytes . An oocyte is a form of genetic material that can be collected for cryoconservation . Cryoconservation of animal genetic resources have been put into action as a means of conserving traditional livestock . </P> <P> The formation of an oocyte is called oocytogenesis, which is a part of oogenesis . Oogenesis results in the formation of both primary oocytes during fetal period, and of secondary oocytes after it as part of ovulation . </P> <Table> <Tr> <Td> Cell type </Td> <Td> ploidy / chromosomes </Td> <Td> chromatids </Td> <Td> Process </Td> <Td> Time of completion </Td> </Tr> <Tr> <Td> Oogonium </Td> <Td> diploid / 46 (2N) </Td> <Td> 2C </Td> <Td> Oocytogenesis (mitosis) </Td> <Td> third trimester </Td> </Tr> <Tr> <Td> primary Oocyte </Td> <Td> diploid / 46 (2N) </Td> <Td> 4C </Td> <Td> Ootidogenesis (meiosis I) (Folliculogenesis) </Td> <Td> Dictyate in prophase I for up to 50 years </Td> </Tr> <Tr> <Td> secondary Oocyte </Td> <Td> haploid / 23 (1N) </Td> <Td> 2C </Td> <Td> Ootidogenesis (meiosis II) </Td> <Td> Halted in metaphase II until fertilization </Td> </Tr> <Tr> <Td> Ootid </Td> <Td> haploid / 23 (1N) </Td> <Td> 1C </Td> <Td> Ootidogenesis (meiosis II) </Td> <Td> Minutes after fertilization </Td> </Tr> <Tr> <Td> Ovum </Td> <Td> haploid / 23 (1N) </Td> <Td> 1C </Td> <Td> </Td> </Tr> </Table>

Function of the secondary oocyte in the ovary