In angiosperms,the functional megaspore develops into .............

If $100$ megaspore mother cells undergo meiosis,then how many megaspores are formed $(a)$,how many degenerate $(b)$,and how many remain functional $(c)$?

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 $- R$
$\quad\quad\quad\quad P \quad\quad\quad Q \quad\quad\quad R$

The megasporangium proper of an angiosperm ovule is represented by:

Embryo sac consists of

The ovule in pea is: