Answer:
The radial symmetry animals get information through their receptor cells and neurons present all over their body.
Explanation:
Radial symmetry animals can be cut in different directions. The central axis separates it into 2 equal halves and again it can be cut into 4 directions.
e.g. Hydra, sea urchin, starfish, etc
They are invertebrates have sense organs, but these sense organs are not well defined. Each symmetry of the body has sense organs. These radial symmetry organisms have oral and aboral parts.
Sea urchins, starfishes, Hydra are light sensitive. They possess photoreceptor cells in their epithelial linings. Starfishes also sensitive to touch, light, and temperature. Their spines and tube feet have motor nerves, which control their movement.
Eyespots in starfishes also help in detecting objects. It is composed of epithelial cells and responds to light. They lack a brain but have a complex nervous system. This nervous system consists of a sensory nerve and motor nerve. It spreads all over the body. Hence starfishes can react according to the stimuli.
