Most of the embryo sac in Angiosperms is made up of 7 cells and 8 nucleus (Polygonum type). It consists of three antipodal cells, one central cell, two synergids and one egg cell. These antipodal cells are haploid, and they degenerate after fertilization, central cell bear two haploid nuclei which later fuse to form secondary nucleus. Egg cell fuses with first male gamete and form diploid zygote, the process is called syngamy. Secondary nucleus fuses with second male gamete and form triploid Primary endosperm nucleus, this process is called triple fusion. Whereas synergids always remain haploid and degenerates one by one, first during entry of first male gamete and second after syngamy.