Fill the blanks
(i) The megasproe mother cell undergoes ______and forms a linear tetrad of megaspores
(ii) ___________embryo sac is most common in angiospermic plants
(iii) Mature female gametophyte in angiosperms is ___________celled and ____________nucleated
(iv) ____________are the vegettive cells of the embryo sac
(v) Filiform apparatus is present in ______________of embryo sac