Question

What is the ploidy of nucellus, MMC, functional megaspore, and female gametophyte?

Answer 1

Ploidy:

Ploidy refers to the complete set of chromosomes in a cell.

1. Nucellus forms a major part of the ovule and consists of a diploid layer of cells that surrounds the embryo sac. It provides nutrition to the embryo. The nucellus is part of the sporophyte and the ploidy is 2n.
2. The megaspore mother cell (MMC) is also part of the sporophyte and the ploidy is 2n.
3. A total of four haploid megaspores are formed by the meiotic division of MMC out of which three undergo degeneration and only one is a functional megaspore. Hence, the ploidy is n.
4. The functional megaspore forms the female gametophyte which is also haploid; therefore, the ploidy is n.