Question

Ploidy of ovary, anther, egg, pollen, male gamete, and zygote are respectively:-
A. 2n, 2n, n, 2n, n, 2n
B. 2n, 2n, n, n, n, 2n
C. 2n, n, n, n, n, n
D. 2n, 2n, n, 2n, 2n, 2n

Answer 1

Hint: Ploidy is the number of chromosomes present in the nucleus of a cell. Chromosomes exist in pairs in a normal somatic cell. This condition refers to diploidy. During meiosis, the number of chromosomes reduced to half at anaphase stage. This condition is called haploidy. As gametes are produced through meiosis, they are haploid in structure. The two gametes from different parents fuse together to form a zygote, which is a diploid structure.

Complete Step by Step Answer:
Ovary is the female reproductive part of the plant. It contains ovules which upon fertilisation develop into seeds. Thus, it is diploid (2n) in structure.
Anther is the male reproductive part of the flower and is diploid (2n).
Egg is the female gamete produced by meiosis due to which it contains half the number of chromosomes making it haploid (n).
Pollen is the male gamete in flowering plants and is haploid (n).
Male gamete is also haploid (n) in structure.
Zygote is formed due to fusion of male and female gamete, thus making it diploid (2n).

Hence the correct option is B:- 2n, 2n, n, n,n, 2n

Note: In a normal somatic cell, chromosomes are in pairs and thus are diploid but in some conditions the number of chromosomes can be more than two as well. When the nuclei of a cell contains three or more than three chromosomes, the condition is referred to as polyploidy. In plants, it may occur due to repeated multiplication of nucleus without the division of cytoplasm. Animals having abnormal numbers of chromosomes are mostly sterile.