Question

Which one of the following is haploid?
A) Oogonia
B) Primary spermatocyte
C) Primary oocyte
D) Secondary oocyte

Answer 1

Hint:Haploid cells are the cells which contain a single set of chromosomes. Haploid cells are produced as a result of meiosis. Examples of haploid cells is male and female gametes.

Complete answer:
In animal cells, diploid cells undergo reduction division to form haploid cells through meiotic division and cell differentiation.
Let us discuss the given options-
>Oogonia- It is a small diploid cell. It is produced by the female germ cell which produces a primordial germ cell that undergoes mitosis and forms oogonia.
>Primary spermatocyte- They are game gametocytes in animals. These are formed by immature germ cells. They are diploid in nature and contain 2n chromosomes.
>Primary oocyte- These are the diploid cells. Its division is arrested at prophase I in the female ovary till puberty. It undergoes division and produces secondary oocytes.
>Secondary oocyte- It is the haploid cell formed from the primary oocyte after it has completed its first meiotic division and produces female ova which is haploid in nature. Secondary oocytes are the immature ovum which are formed after ovulation and have not undergone fertilisation yet.

Thus the correct answer is option (D). Secondary oocytes are haploid in nature.

Note:The asexually reproducing organisms are haploid in nature. Sexually reproducing organisms are diploid as they contain two sets of chromosomes one from each parent. Eggs and sperms of human beings are haploid in nature.