Which germ layer is the outermost and gives rise to sense organs, nerves, and the outer layer of skin?

Which germ layer is the outermost and gives rise to sense organs, nerves, and the outer layer of skin?

• A. Mesoderm
• B. Endoderm
• C. Coelom
• D. Ectoderm

Answer: (D)

During early development, three germ layers form, and the outermost layer is the ectoderm. This ectoderm gives rise to the nervous system, including nerves and sense organs, and to the epidermis, the outermost layer of skin. That’s why this option is the best answer. The mesoderm forms muscles, bones, and the circulatory system; the endoderm lines the gut and respiratory tract and forms associated glands; the coelom is a body cavity, not a germ layer. So the ectoderm’s derivatives perfectly match sense organs, nerves, and the outer skin.

During early development, three germ layers form, and the outermost layer is the ectoderm. This ectoderm gives rise to the nervous system, including nerves and sense organs, and to the epidermis, the outermost layer of skin. That’s why this option is the best answer. The mesoderm forms muscles, bones, and the circulatory system; the endoderm lines the gut and respiratory tract and forms associated glands; the coelom is a body cavity, not a germ layer. So the ectoderm’s derivatives perfectly match sense organs, nerves, and the outer skin.