Spermatogenesis and Oogenesis
Spermatogenesis vs. Oogenesis - What's The Difference?
Spermatogenesis takes place in males in the seminiferous tubules of the testes from the time of sexual maturity during puberty onwards. It then takes 48 days for the primordial germ cells to divide and produce mature sperm.
Oogenesis, on the other hand, occurs in females and is completed by the third month of prenatal development. The oogonial cells are then arrested in the prophase I phase of meiosis until the female reaches puberty. At this point, one cell undergoes meiosis per month.
The Process of Spermatogenesis
The primordial germ cells undergo mitosis and produce some fine diploid spermatogial cells (46 homologous chromosomes). These spermatogeal cells then undergo mitosis and produce first degree spermatocytes (46 homologous chromosomes). This first degree spermatocyte then undergoes meiosis and produces two second degree spermatocytes (46 sister chromatids). These second degree spermatocytes then undergo meiosis to produce haploid sperm (23 sister chromatid). :)
The Process of Oogenesis
Primordial germ cells int he ovarian cortex undergo 30 mitotic divisions and produce some oogonial cells. These oogonial cells undergo mitosis and produce first degree oocytes. These first degree oocytes then undergo meiosis I and are arrested in prophase I until puberty.
At puberty, one oocyte per month resumes meiosis. :)
This resulting second degree oocyte undergoes meiosis II and produces one haploid ovum and three polar bodies. =) Polar bodies are just crap cells that disintegrate. The ovum is what's important. ;)
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