Question

The difference between oogenesis and spermatogenesis is

• A. oogenesis begins at puberty and spermatogenesis during embryonic development.
• B. oogenesis results in formation of four haploid ova from a primary oocyte, while during spermatogenesis only one sperm is formed from a primary spermatocyte.
• C. the cytoplasmic division is unequal in oogenesis and equal in spermatogenesis.
• D. spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed at the time of birth.

Answer 1

Answer: (C)

Oogenesis is formation of female gametes while spermatogenesis is formation of male gametes. Both begins with primary mother cells in the gonads. Primary oocyte undergoes meiosis 1 and forms secondary oocyte and first polar body while Primary spermatocyte undergoes meiosis1 and forms two secondary spermatocyte. The process is the same in both but the daughter cells formed are different. In oogenesis, the daughter cells are of unequal size i.e. secondary oocyte is larger than the first polar body because secondary oocyte has maximum amount of cytoplasm retained in it. This unequal division is important because incase sperms approach these gametes, there is a chance of fertilization and zygote formation. Hence cytoplasm can act as stored food for the zygote. While in spermatogenesis the daughter cells formed are of same size as seen in Meiosis of other cells. This is the main difference.