In botanical terms, the wheat kernel, like that of other cereal grains, is a caryopsis or single seeded, indehiscent dry fruit. Caryopsis, is ovoid in shape with a longitudinal crease.
The length of the kernel varies with the type of wheat and conditions of growth, but is generally about 4-8 mm, The outer layer or epidermis is a sheath for other layers of cells, which constitutes a pericarp about 50 um thick.
During growth the lateral potion of the seed fold inward and the seed elongates, forming a fold or groove upon its upper surface.
Wheat kernels are the part of the plant that is milled into flour. The wheat kernel as whole grain has four main parts: the germ, the endosperm, the bran and the husk.
Endosperm makes up the bulk of the wheat kernel, over 80 percent of it. It is the whitest part, partly because it contains mostly starch.
The bran acts a s barriers to protect the grain and makes up over 8% of the weight of the kernel.
The germ is the part that grows into a wheat plant and therefore contains concentrated food to support the new life - it is especially rich in vitamins and minerals. Wheat germ represent only 2-3% by weight of the kernel and it is available as a separate entity because it is an important source of vitamin E.
Wheat kernel