Which of the following structures is NOT formed by neural crest cells?

• A. Cranial nerves.
• B. Spinal cord.
• C. Spinal nerves.
• D. Sensory ganglia.

Answer: (B)

Verified step by step guidance

1. Understand the role of neural crest cells: Neural crest cells are a group of cells that originate from the embryonic ectoderm and migrate to various parts of the body, contributing to the formation of diverse structures.
2. Identify structures formed by neural crest cells: Neural crest cells are known to form cranial nerves, spinal nerves, and sensory ganglia, among other structures.
3. Recognize the exception: The spinal cord is primarily formed from the neural tube, not neural crest cells.
4. Differentiate between neural tube and neural crest: The neural tube gives rise to the central nervous system, including the brain and spinal cord, while neural crest cells contribute to the peripheral nervous system and other structures.
5. Conclude which structure is not formed by neural crest cells: Based on the understanding that the spinal cord is derived from the neural tube, it is not formed by neural crest cells.