Which of the following structures degenerate after fertilization in angiosperms?

Match Column-$I$ with Column-$II$ and select the correct option using the codes given below:

Column-$I$	Column-$II$
$(A)$ Pistils fused together	$(1)$ Gametogenesis
$(B)$ Formation of gametes	$(2)$ Monocarpellary
$(C)$ Hyphae of higher Ascomycetes	$(3)$ Syncarpous
$(D)$ Unisexual female flower	$(4)$ Dikaryotic

Give a scientific reason: Variations are expected in sexually reproducing plants.

Assertion : Pollen mother cells $(PMCs)$ are the first male gametophytic cells.
Reason : Each $PMC$ gives rise to two pollens.

Provide information about pre-fertilization structures and events in flowering plants.

Indicate the stages where meiosis and mitosis occur $(1, 2$ or $3)$ in the flow chart: Megaspore mother cell $\xrightarrow{1}$ Megaspores $\xrightarrow{2}$ Embryo sac $\xrightarrow{3}$ Egg.