In the grass family ( eg. Maize ) fruit is single-seeded where the pericarp and the seed coat are fused together to produce the husk. Just below the husk, there is a layer of cells known as the aleurone layer, this layer stores protein. There is a large endosperm that stores starch. The embryo lies on one side of the endosperm & consists of a single cotyledon called scutellum & embryonal axis. The region of the embryonal axis that points downward from the point of attachment of cotyledons is a radicle and it is covered with a protective sheath known as coleorhiza. The region of an embryonal axis that points upward from the point of attachment of cotyledon is known as a plumule, it is covered by a foliaceous sheath called coleoptile.
ii) Why cannot we use the term maize seeds for maize grains?
Ans: We cannot use the term seeds for maize grain because the seed is not completely developed from the embryo but retains a part of the endosperm.