The secondary nucleus in the middle of an embryo sac of angiosperms is:

The female gametophyte of angiospermic plants is represented by:

How many pistils are present in a monocarpellary gynoecium?

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 embryo sac represents which stage?

Match the following columns regarding the components of the embryo sac:

Column $I$	Column $II$
$(a)$ Sex cell	$(1)$ Synergid cells
$(b)$ Synergid cell	$(2)$ Antipodal cells
$(c)$ Cell opposite to micropyle	$(3)$ Egg cell
$(d)$ Central cell	$(4)$ Secondary nucleus