Variations in Seed Composition

There is great variation in seed composition. In some seeds, the cotyledons have a high oil content (for example, in soy beans and peanuts). In others, the cotyledons store starch. Many bean-family plants have seeds with a high protein content. Some seeds contain sugar (onion seeds, for instance). The seeds of sweet corn contain sugar that changes to starch in maturity. Seeds are important sources of food for people and other animals. Rice, wheat, oats, barley, corn, beans, peas, and nuts are all important food sources.