Introduction to Sexual Reproduction in Humans

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Introduction to sexual reproduction in humans
Reproduction is the process by which humans gives rise to new individuals. Sexual reproduction is the process that involves the fusion of two gametes, sperm (male gamete) and egg (female gamete). In human these gametes are produced in different sexes, the male and female. Reproduction in humans is performed by reproductive systems, the male and female reproductive systems. The main organs of male reproductive system are testis and gonads and of female reproductive system are vagina, ovaries, and uterus. Main events in sexual reproduction of humans are production of sperms and egg, copulation, and fertilization. (Sexual Reproduction in Humans) : Production of Gametes

Sperms are produced in seminiferous tubules present in male reproductive organ testis. This process is known as spermatogenesis. The precursors of the sperm the diploid spermatogonium divides mitotically to produce numerous spermatogonia and differentiate into spermatocytes. Spermatocytes undergo meiotic cell division to produce, 4 haploid spermatids. Spermatids differentiate and develop into sperm. Sperms are single celled male gametes with a head, midpiece, and a tail. Ovum (egg cell), the female gamete is produced in the ovaries of female reproductive system. This process is known as oogenesis. In contrast to males, in females the initial steps in egg production occur prior to their birth. Diploid oogonia and primary oocytes produced in fetus and by the time she is born, females have about 1–2 million oocytes. In oocytes the first meiotic division (meiosis I) will initiated and then stopped. No further development occurs until the girl becomes sexually mature. After maturity the primary oocytes recommence their development, usually one at a time and once a month. The primary oocyte grows further and completes the meiosis I, forming a large secondary oocyte and a small polar body. Only after fertilization meiosis II will be completed. By completion of...
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