Question

Which among the following has 23chromosomes?

• A. Spermatogonia
• B. Zygote
• C. Secondary oocyte
• D. Oogonia

Answer 1

The correct option is C

Secondary oocyte

• Secondary oocyte has 23 chromosomes as it is a product of the meiotic division of primary oocyte during oogenesis in the ovary.
• Oogenesis is initiated at the foetal ovary in the early embryonic stage of female and a fixed number of oogonia (gamete mother cells) are formed at the birth of the female child. No more oogonia are added after birth. All the oogonia are diploid (2n) and contain 46 chromosomes.
• Spermatogonia are the immature male germ cells that produce sperms. Each spermatogonium is diploid (2n) and contains 46 chromosomes.
• The haploid nucleus of the sperms and that of the ovum fuse together to form a diploid(2n) zygote i.e., 46 chromosomes.