In human development, what does the ectoderm primarily form?

• A. The digestive tract lining
• B. The nervous system and skin
• C. The circulatory system
• D. The skeletal muscles

Answer: (B)

Verified step by step guidance

1. Understand the three primary germ layers in human development: ectoderm, mesoderm, and endoderm.
2. Recognize that each germ layer gives rise to specific tissues and organs in the body.
3. Identify that the ectoderm is the outermost layer and primarily forms structures such as the nervous system and the skin.
4. Differentiate the roles of the other germ layers: the mesoderm forms structures like the circulatory system and skeletal muscles, while the endoderm forms the lining of the digestive tract.
5. Conclude that the ectoderm is responsible for forming the nervous system and skin, distinguishing it from the functions of the mesoderm and endoderm.