Which set of terms would most likely be used in a description of the nervous system of chordates?
A. No brain, fused ganglia, tympana.
B. No brain, nerve net, modified neurons.
C. Brain, fused ganglia, ventral nerve cord.
D. Brain, dorsal nerve cord, highly developed receptors.
Chordates are a group of animals such as fish, frogs, snakes, birds, dogs, monkeys and humans. We all have central nervous systems made up of a brain and a dorsal (back) nerve cord. We all have highly developed receptors to detect changes in the environment for us to respond to. Fused ganglia is a primitive brain found in earthworms, tympana are primitive ears found in grasshoppers, and nerve nets are branched nerves without direction found in the hydra.