Embryo sac is the female gametophyte. It is an eight nucleated structure consisting of egg apparatus, polar nuclei and antipodal cells.
-
Egg Apparatus: After fertilization, gives rise to diploid zygote which later on develops into an embryo.
-
Polar nuclei: The two polar nuclei fuse to form single diploid secondary nucleus. The secondary nucleus forms the triploid endosperm nucleus, which produces endosperm in which food for the embryo is stored.
-
Antipodal cells: These are nutritive cell. They degenerate during seed formation.