The maize grain is a monocotyledon seed. Caryopsis is a small one-seeded fruit of the maize. In maize grain, the seed coat which is also known as testa is combined with the fruit wall. The maize grain is a yellow, triangular-shaped seed, externally. The outermost layer of endosperm is made up of only protein which is named as aleurone layer. Across the aleurone layer, on the other side of the endosperm lies the embryo. This embryo comprises a single large and shield-shaped cotyledon which is known as scutellum. The scutellum is embedded with the embryo axis, which is consist of the plumule and radicle on either end. The sheath covering these two ends are called coleoptile and coleorhiza, respectively.
