Which nervous system is characteristic of cnidarians?

Which nervous system is characteristic of cnidarians?

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

Answer: (A)

Cnidarians rely on a diffuse nerve net rather than a centralized brain or spinal cord. Neurons are spread through the body and connect sensory cells to muscle fibers, enabling basic coordination and reflexive responses like tentacle movements and simple swimming. This decentralized setup suits their radial symmetry and diploblastic organization, giving them the ability to respond to stimuli without a centralized processing center. In contrast, a brain or spinal cord implies centralized processing found in more complex animals, which cnidarians do not have.

Cnidarians rely on a diffuse nerve net rather than a centralized brain or spinal cord. Neurons are spread through the body and connect sensory cells to muscle fibers, enabling basic coordination and reflexive responses like tentacle movements and simple swimming. This decentralized setup suits their radial symmetry and diploblastic organization, giving them the ability to respond to stimuli without a centralized processing center. In contrast, a brain or spinal cord implies centralized processing found in more complex animals, which cnidarians do not have.