Explain the process of oogenesis.
(please explain because i want the proper answer of this ques.)
Solution:
Oogenesis
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The ovum is formed by the process of oogenesis.
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It starts during embryonic growth and millions of gamete mother cells (oogonia) are formed in the foetal ovary.
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These cells undergo meiosis, but get temporarily arrested at the prophase and are called primary oocytes.
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Before reaching puberty, a large number of primary oocytes degenerate and the remaining ones get surrounded by layers of granulosa cells and new theca and are called secondary follicles.
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The secondary follicles are then converted into tertiary follicles that have characteristic fluid-filled cavity called antrum. At this stage, the primary oocyte present within the tertiary follicle completes meiosis, which results in the formation of haploid secondary oocyte and a tiny polar body.
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This tertiary follicle further changes into the Graafian follicle. The secondary oocyte is surrounded by the zone pellucida.
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Then the Graafian follicle ruptures to release the ovum by ovulation.