Which of the following has 23 chromosomes?

The correct answer is Option (4) → Spermatids

A human body cell is diploid and has 46 chromosomes. Gametes and the cells formed after the first meiotic division are haploid and have 23 chromosomes.

Option (1) Zygote — Incorrect. The zygote is formed when the haploid nucleus of the sperm fuses with that of the ovum, so it is diploid with 46 chromosomes.

Option (2) Oogonia — Incorrect. Oogonia are the gamete mother cells formed in the fetal ovary. They have not yet entered meiosis, so they are diploid.

Option (3) Spermatogonia — Incorrect. Each spermatogonium is diploid and contains 46 chromosomes.

Option (4) Spermatids — Correct. Spermatids are formed by the second meiotic division of the haploid secondary spermatocytes. They are haploid and have 23 chromosomes.

NCERT Extract:
Gametogenesis – “… Each spermatogonium is diploid and contains 46 chromosomes. Some of the spermatogonia called primary spermatocytes periodically undergo meiosis. A primary spermatocyte completes the first meiotic division (reduction division) leading to formation of two equal, haploid cells called secondary spermatocytes, which have only 23 chromosomes each. The secondary spermatocytes undergo the second meiotic division to produce four equal, haploid spermatids (Figure 2.5).”
Fertilisation and Implantation – “… Soon the haploid nucleus of the sperms and that of the ovum fuse together to form a diploid zygote.”

Figure 2.8 (a) Schematic representation of Spermatogenesis