Final answer:
The ectoderm is the outermost germ layer in an embryo that differentiates to form the epidermis, which includes skin, hair, and nails, as well as the central and peripheral nervous systems and sensory organs.
Step-by-step explanation:
The ectoderm, which is the outermost germ layer in an embryo, differentiates to form several key structures in a developing organism. This layer gives rise to the epidermis, which includes the skin, hair, and nails, as well as the nervous system, encompassing both the central and peripheral nervous systems and sensory organs. The process of creating these mature cells is known as differentiation, during which embryonic stem cells express specific genes to become definitive cell types. The ectoderm plays an integral part in the creation of these structures, and its role is vital in the organogenesis stage of prenatal development. Mesoderm and endoderm are the other germ layers that contribute to the formation of other body tissues such as muscles, skeleton, and internal organs.