An oocyte is fertilizable for up to 24 hours; sperm are viable within the female reproductive tract for up to 72 hours. Hundreds of sperm must release their acrosomal enzymes to break down the egg's corona radiata. Following sperm penetration, the secondary oocyte completes meiosis II. Then ovum and sperm nuclei fuse (fertilization), forming a zygote.
If fertilization occurs, embryonic development begins immediately. Cleavage, a rapid series of mitotic divisions without intervening growth, begins with the zygote and ends with a blastocyst.The embryo will becomes a baby.
Spermatogenesis (sperm production) begins at puberty in seminiferous tubules in response to FSH . Spermatogenesis involves meiosis, a special nuclear division that halves the chromosomal number in resulting spermatids. An additional process that strips excess cytoplasm from the spermatid, called spermiogenesis, is necessary for production of functional, motile sperm.
Oogenesis (production of female sex cells) occurs in ovarian follicles, which are activated at puberty by FSH and LH to mature and eject oocytes (ovulation) on a cyclic basis . The female egg (ovum) is formed only if sperm penetrates the secondary oocyte. In females, meiosis produces only one functional ovum (plus three nonfunctional polar bodies) as opposed to the four functional sperm per meiosis produced by males.
I think that's enough, you have understand it so far. See you and good luck.
1 komentar:
Score:B- Not good enough!
-use your own words, be yourself
-always mention the source
Mr T
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