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Spermatogenesis is the production process of sperm. It takes place in the testes, in the somniferous tubules. Oogenesis is the production of egg cells in the ovaries.
In spermatogenesis, the germinal epithelium cell divides by mitosis to form one daughter spermatogonia and the other becomes a daughter germinal epithelium cell. The spermatogonium undergoes a growth phase which develops into a primary spermatocyte (Diploid).In oogenesis, the germinal epithelium cell also divides by mitosis to form 1 oogonia and the other becomes a daughter germinal epithelium cell. The Oogonia then goes through a growth phase and forms a primary oocyte (Diploid) contained in a primary follicle.
In spermatogenesis, the primary spermatocyte (diploid) undergoes meiosis 1 and cell division to form secondary spermatocyte (haploid). Whereas the primary oocyte (Diploid) divides by meiosis, division then stops at prophase 1, and continues at puberty. However when division takes place, it is unequal, which forms 1 secondary oocyte (haploid) and a first polar body (haploid) which degenerates and dies.
Now, the 2 secondary spermatocytes, divide by meiosis 2 and cell division to form spermatids (haploid). The spermatids then differentiate into sperm cells (Haploid). From puberty onwards the testes produce sperm continuously. At any time, there are millions of sperm at all stages of development. When the sperm are fully formed, they pass out of the testis, into the epididymis. Here the sperm mature and gain motility. The timing of release depends on the sexual activity of a man. Whenever ejaculation occurs, millions of sperm are moved by muscle action along the sperm duct from the epididymis to the urethra.
The secondary oocyte (haploid) and first polar body (haploid) undergoes meiosis 2 and cell division to form 1 egg (haploid) and a second polar body (haploid) which also degenerates and dies. This complete cycle happens once per menstrual cycle and usually only...