In angiosperms embryosac is developed from

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

The germination of pollen grain results in the formation of

Location and Function :

$1.$ Nucellus

$2.$ Filiform structures

Female gametophyte of a typical dicot at the time of fertilization is

The sequence of development of embryo sac is