Final answer:
The largest part of the grain kernel is the endosperm. It is the central portion of the kernel, primarily composed of stored starch, which substantially exceeds the size of other components such as the germ and bran.
"the correct option is approximately option A"
Step-by-step explanation:
The largest part of the grain kernel is the endosperm. In the structure of a wheat seed, which can also be considered a fruit, there are three primary components: the embryo (also known as the germ), the endosperm, and the bran which is the fused seed coat and fruit wall. Among these, the endosperm is the significant portion constituting the stored food mainly composed of starch, and it makes up the bulk of the kernel. White bread is made from refined wheat, meaning it has had the bran and germ removed, leaving primarily the endosperm, which is rich in carbohydrates.
The germ is the part of the seed that develops into the new plant and is much smaller in size compared to the endosperm. Although the germ contains high levels of nutrients such as proteins, fats, minerals, and vitamins, it only represents a small fraction of the seed's mass.
The bran is the outer layer that provides protection to the seed and contains indigestible fiber along with some proteins and fats. When making whole-grain products, all components of the kernel are utilized, making the product more nutritious but also more perishable. The hull or hull of corn is another part of a kernel but is not as significant in size as the endosperm.