The haploid cell which divides by mitosis to form the embryo sac is:

The megasporangium proper of an angiosperm ovule is represented by:

If the endosperm mother cell of an angiosperm plant has $24$ chromosomes,the number of chromosomes in the $MMC$ will be:

Identify the parts of the pistil labeled as $P$,$Q$,and $R$:
Receptive surface for pollen grains $- P$
Elongated slender part of the pistil $- Q$
Basal swollen part of the pistil $- R$
$\quad\quad\quad\quad P \quad\quad\quad Q \quad\quad\quad R$

With a neat diagram,explain the $7$-celled,$8$-nucleate nature of the female gametophyte.

Filiform apparatus is a characteristic feature of