GAMETOGENESIS | Spermatogenesis and Oogenesis | for Class 12 and NEET 2020.

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Gametogenesis includes Spermatogenesis and Oogenesis and means simply the process of formation of gamet.

Spermatogenesis is the process by which spermatozoa are produced from spermatogonia bhai mitosis and meiosis. the initial cell in the pathway are called spermatogonia, which form primary spermatocytes by mitosis. the primary spermatocyte divides meiotically (miosis l ) into tu spermatocytes, each secondary spermatocyte divides into two spermatids by meiosis ll . this develop into macha spermatozoa, also known as sperm cell. thus, the primary spermatocyte gives rise to two cells (the secondary spermatocytes ) and the two secondary spermatocytes are then subdivided to produce 4 spermatozoa.

spermatozoa are mature male gametes in many reproducing organism.
thus, is per metro genesis is male version of gametogenesis, of which the female equivalent is oogenesis. in mammals it occurs in seminiferous tubule of male testis in a stepwise fashion. spermatogenesis is highly dependent upon optional condition for the process to occur correctly, and is essential for sexual reproduction. DNA methylation and histone modification have been implicated in regulation of this process. it starts at puberty and usually continuous uninterrupted until death, although a slight decrease can be discovered in the quality of produced sperm with increase in age.
the entire process of spermatogenesis can be broken up into several distinct stages, each corresponding to a particular type of cell in human. in the following table, ploidy copy number and chromosome count are for one cell , generally prior to DNA synthesis and division. the primary spermatocyte is arrested after DNA synthesis and prior to division.

in spermatogenesis a diploid spermatogonium which three sides in the basil compartment of the seminiferous tubule divide mitotically producing to deployed intermediate cell called primary spermatocyte. each primary spermatocyte then moves into compartment of seminiferous tubule and duplicate its DNA and subsequently undergoes mitosis 12 produced to haploid secondary spermatocyte which will letter divide once more into haploid spermatids. this division implicates source of genetic variation such as random inclusion of either paternal chromosome and chromosomal crossover to increase the genetic variability of the gametes.

oogenesis takes place in cortex of ovary.
oogenesis starts in fetal life then arrest till property then restart and it goes on till menopause.

This video details about gametogenesis ( Spermatogenesis and Oogenesis) for class 12 and NEET 2020.

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