Question

What are the ploidy levels of the 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 is referred to as the number of chromosomes in the genome of an organism.

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

Additional information
Ploidy level tells about the number of chromosomes present in the cell or genome of an organism.

It is of two main types:
1. Haploid – the condition of a cell having a single set of chromosomes.
2. Diploid – the condition of a cell having two sets of chromosomes.

So, the correct answer is 2n, 2n, n, n.

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