PRIMITIVE NERVOUS SYSTEMS.
D000818:Animals; D005075:Biological Evolution; D003063:Cnidaria; D009420:Nervous System; D010828:Physiology, Comparative; D012106:Research; D011984:Sensory Receptor Cells
COELENTERATA; EVOLUTION; EXPERIMENTAL LAB STUDY; NERVOUS SYSTEM; PHYSIOLOGY, COMPARATIVE; RECEPTORS, NEURAL