Which set of terms would most likely be used in a description of the nervous system of chordates?
(a) Brain, dorsal nerve cord, highly developed receptors
(b) Brain, fused ganglia, ventral nerve cord
(c) No brain, fused ganglia, tympana
(d) No brain, nerve net, modified neurons
(a) Brain, dorsal nerve cord, highly developed receptors
Explanation:
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.