This statement is true. A grain has three parts: the germ, endosperm, and bran. The germ is the embryo of the seed and contains essential nutrients such as vitamins, minerals, and healthy fats. The endosperm is the largest part of the grain and contains carbohydrates, protein, and some vitamins and minerals. The bran is the outer layer of the grain and contains fiber, B vitamins, and minerals. Whole grains contain all three parts, while refined grains have had the bran and germ removed, leaving only the endosperm.