Question

What is the ploidy level of nucellus, MMC, functional megaspore and female gametophyte?
A)2n, n, 2n, 2n
B)2n, n, 2n, n
C)2n, 2n, n, n
D)n, 2n, n, n

Answer 1

Hint: Ploidy level gives information about the number of chromosomes present in the cell or genome of an organism. It is of mainly of two types:
1. Haploid - the condition of a cell that shows a single set of chromosomes.
2. Diploid - the condition of a cell that shows two sets of chromosomes.

Complete answer:
Ploidy level of the various parts of the female megaspore depends upon their origin.
The nucellus is the layer that surrounds and covers the integuments in the ovule. It is used to store food to provide energy during megasporogenesis. So, the ploidy level of nucellus is the same as other plant cells. The ploidy level of the main plant is diploid. So, the ploidy level of nucellus is 2n.
MMC is also termed as microspore mother cell, also known as meiocyte which undergoes meiotic division and give rise to female gametes. So, its ploidy is 2n.
Functional megaspore is formed as a result after MMC undergoes several meiotic divisions. It produces megaspore tetrad out of 4 megaspore tetrad 3 of them degenerate and only one remains functional which is called functional megaspore. As it is formed as a result of meiosis so it's ploidy level is half of MMC which will be n.
The female gametophyte is defined as the female gamete. It is already said that gametes are haploid so the ploidy level of female gametophyte is n.

Hence, the correct answer is option (C)

Note: Polyploidy is defined as the condition where an organism consists of more than two sets of chromosomes. It performs a major role in producing variation among individuals.