In seed plants, a structure consisting of the male gametophyte enclosed within a pollen wall. A tough outer covering of a seed, formed from the outer coat of an ovule; in a flowering plant, it encloses and protects the embryo and endosperm.
Seed plants produce pollen tiny structures that contain the cells that will later become sperm cells. Pollen delivers sperm cells directly near the eggs. After sperm cells fertilize the eggs, seeds develop. A seed is a structure that contains a young plant inside a protective covering.
