The egg apparatus consists of $.......$

In angiosperms,the following events occur during megasporogenesis and megagametogenesis:
$(i)$ Differentiation of megaspore mother cells
$(ii)$ Meiosis of the megaspore mother cell
$(iii)$ Formation of a linear tetrad
$(iv)$ Mitotic division of the functional megaspore
$(v)$ Degeneration of $3$ megaspores
$(vi)$ Formation of embryo sac
$(vii)$ Fusion of polar nuclei
The correct sequence is:

$A$ typical angiosperm embryo sac at maturity is:

What is the ploidy of the megaspore mother cell $(MMC)$?

The filiform apparatus is found in ........

Which of the following types of embryo sac is commonly found in angiosperms?