Question

Which of the following is/are haploid in human beings?
I) Primary spermatocyte
II) Secondary spermatocyte
III) Primary oocyte
IV) Germ cells
V) Secondary oocyte

• A. I, II, III and V
• B. II and V
• C. II, V and IV
• D. I, II and V

Answer 1

The correct option is B II and V

Haploid cells have a single set of chromosomes whereas diploid cells have two sets of chromosomes.

Cells that are capable of giving rise to gametes are called germ cells. In human beings these cells are diploid.

In males, primary spermatocytes are formed as a result of mitosis and differentiation from spermatogonia. Spermatogonia is a diploid cell. Thus the primary spermatocyte is also diploid.

Whereas the primary spermatocyte undergoes meiosis to produce secondary spermatocytes. Since the primary spermatocyte is diploid, meiosis of this cell would result in haploid secondary spermatocytes.

Similarly in females, the diploid oogonia undergoes mitosis and differentiation to produce the diploid primary oocyte. Further the primary oocyte will undergo meiosis to produce haploid secondary oocyte.

Hence, the secondary spermatocyte and secondary oocyte are haploid cells.