Question

Exactly! In spermatogenesis, the cytoplasm is evenly divided, resulting in the production of four sperm cells. In contrast, during oogenesis, the cytoplasm is unequally distributed, with one cell receiving almost all the cytoplasm to become the egg, while the other three cells, called polar bodies, are much smaller and functionally contribute only genetic material and cellular organelles to the main cell.

Answer 1

Oogenesis is a type of gametogenesis in which an oocyte undergoes meiotic divisions to become a mature ovum, with cytoplasm unevenly distributed, compared to uniform division in spermatogenesis. Fertilization triggers the completion of meiosis in the oocyte, resulting in a haploid ovum ready to develop into an embryo.

Step-by-step explanation:

The process of oogenesis and its contrast with spermatogenesis are key aspects of human reproduction and development. In oogenesis, a primary oocyte begins meiosis before birth and is paused in the prophase stage until puberty. When hormones stimulate the continuation of meiosis, the primary oocyte completes the first division unequally, forming a large secondary oocyte with most of the cellular material and a small polar body that often degrades. Only if fertilization occurs does the secondary oocyte proceed with the second division of meiosis, ultimately forming the mature haploid ovum and another polar body. In contrast, during spermatogenesis, the cytoplasm is evenly divided among the four resulting haploid sperm cells after two meiotic divisions, each developing a flagellum tail and compact head for motility and fertilization.

Fertilization is crucial for the completion of oogenesis. If a sperm penetrates the secondary oocyte in the fallopian tube, meiosis II is completed, giving rise to a fertilized egg containing a full set of chromosomes and substantial cytoplasm necessary for early embryonic development.