Question
What is oogenesis? Give a brief account of oogenesis.
✓
Answer
The process of the formation of a mature ovum in the ovary from the oogonia in females is known as oogenesis.
Germ cell of the female foetus divide to produce oogonia (gamete mother cell). No more oogonia are formed or added after birth. A diploid oogonium or egg mother cell increases in size and gets transformed into a diploid primary oocyte. This diploid primary oocyte undergoes meiosis or reductional division to form two unequal haploid cells. The smaller cell is known as the first polar body, while the larger cell is known as the secondary oocyte. This secondary oocyte undergoes meiosis II or equational division and gives rise to a second polar body and an ovum. Hence, in the process of oogenesis, a diploid oogonium produces a single haploid ovum while two or three polar bodies are produced.
Germ cell of the female foetus divide to produce oogonia (gamete mother cell). No more oogonia are formed or added after birth. A diploid oogonium or egg mother cell increases in size and gets transformed into a diploid primary oocyte. This diploid primary oocyte undergoes meiosis or reductional division to form two unequal haploid cells. The smaller cell is known as the first polar body, while the larger cell is known as the secondary oocyte. This secondary oocyte undergoes meiosis II or equational division and gives rise to a second polar body and an ovum. Hence, in the process of oogenesis, a diploid oogonium produces a single haploid ovum while two or three polar bodies are produced.
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