. Endosperm formed in majority of angiosperm is-
C. Endosperm is formed when the two sperm nuclei inside a pollen grain reach the interior of an embryo sac or female gametophyte. One sperm nucleus fertilizes the egg, forming a zygote, while the other sperm nucleus usually fuses with the two female polar nuclei at the center of the embryo sac, creating endosperm (double fertilization). Thus endosperm cells are usually triploid (containing three sets of chromosomes) in most of the angiosperms.