Final answer:
The neural plate is formed from neuroepithelial cells that differentiate from the ectoderm. As the neural plate forms, a neural groove appears along the dorsal surface of the embryo. The neural crest cells migrate away from the neural tube and develop into parts of the peripheral nervous system.
Step-by-step explanation:
As the embryo develops, a portion of the ectoderm differentiates into a specialized region of neuroectoderm, which is the precursor for the tissue of the nervous system. Molecular signals induce cells in this region to differentiate into the neuroepithelium, forming a neural plate. The cells then begin to change shape, causing the tissue to buckle and fold inward. A neural groove forms, visible as a line along the dorsal surface of the embryo. The neural crest migrates away from the nascent central nervous system, forming several parts of the peripheral nervous system.