What is oogenesis ? Gametogenesis in females ,which causes formation and maturation of female gametes (ovum ) is called oogenesis . Oogenesis occurs in the ovary of females and begins before birth in female ( spermatogenesis occurs at puberty). Oogenesis is divided into three stages, these are 1) multiplication phase 2) growth phase 3) maturation phase Multiplication phase- During fetal stage of development, primodial germ cell originated in endoderm of yolk sac migrates to ovaries . Some cells are divided mitotically to form oogonia also known as egg mother cells . Approximately 20 lakh oogonia are present in each ovary . It enters growth phase Growth phase- In this phase growth of oogonia occurs . Oogonia drives nutrients from surrounding follicular cells and converted in to primary oocyte . ...
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