What is the embryonic sac? Which are the cells that form the embryonic sac? What are their ploidies?
The embryonic sac is the female gametophyte of angiosperms. The embryonic sac is composed of three cells that remain next to the micropyle, two lateral synergids and the central oosphere (egg); one binucleated cell, the polar nuclei, is placed in the central region; three antipodal cells stay in the opposite side to the micropyle. Since all these cells come by mitosis from the functional megaspore they are haploid (n).
