A typical angiospermic embryo sac, at maturity is

There is a characteristic distribution of the cells within the embryo sac of angiosperms. Three cells grouped at micropylar end is egg-apparatus, three cells are at the chalazal end called antipodals and the large central cell has two polar nuclei, making it 8-nulceate but 7-celled. Monosporic, Polygonum type embryo sac is typical in angiosperms.