In angiosperms, the female gametophyte is called embryo sac. It contains 8 nuclei but 7 cells ' 3 micropylar, 3 chalazal and one central. The three micropylar cells are collectively known as egg apparatus. One middle cell is larger and is called egg or oosphere. The remaining two cells are called synergids or help cells. Each of them (synergids) bears a filiform apparatus in the micropylar region, a lateral hook, chalazal vacuole and a central nucleus.