Which statement best describes the cnidarian nervous system?

• A. Nerve Net
• B. Central Brain
• C. Spinal Cord
• D. Ganglia

Answer: (A)

Cnidarians rely on a nerve net—an interconnected, diffuse network of neurons spread throughout the body. This setup allows simple sensing and coordinated movements (like tentacle grabbing or coordinated swimming) without a single command center. There isn’t a centralized brain or a spinal cord in these organisms; signaling travels through the network in multiple directions and is integrated locally by nearby neurons.

While some cnidarians may have specialized rings or localized nerve clusters, these are still part of the same diffuse network rather than a true centralized brain or spinal cord. That’s why the nerve net best describes their nervous system, distinguishing them from organisms with centralized brains or spinal cords.