The "nervous system" of Hydra consists of

Step-by-step solution

Hydra belonging to the phylum Cnidaria is a genus of fresh-water organisms. They are generally found in the tropical and temperate regions. A nerve net found in Hydra serves as a simple nervous system that connects photoreceptors and touch sensitive nerve cells. These cells are found in the body wall and tentacles. Brain and muscles are absent in Hydra. Also, the nervous system is not as complex found in higher animal nervous systems. The nerve cells of hydra are nonpolarized and signal can move in any direction.