Which part of the barley kernel serves as the precursor to the new barley plant?

The embryo of the barley kernel is the correct choice because it is the part that contains the genetic material and the necessary structures needed to develop into a new barley plant. During germination, the embryo begins to grow and develops into a seedling, ultimately leading to the formation of the new plant.

The husk offers protection to the kernel and plays a role in preventing water loss but does not contribute to the development of the plant itself. The scutellum, although significant as it functions in nutrient absorption during the germination process, is part of the embryo and does not itself serve as the precursor to the plant. The aleurone layer, located just inside the seed coat, has a role in the enzymatic processes that support germination, but it is not involved in developing into the new plant. Thus, while these components play important roles in the overall lifecycle and germination of barley, the embryo is distinctly the part that transitions into the new barley plant.