The simplest animals to display cephalization and centralization of the nervous system are
A) sponges.
B) flatworms.
C) cnidarians.
D) echinoderms.

Question

Quizplus · Accepted Answer

Flatworms have a simple nervous system that consists of an anterior nerve ring and longitudinal nerve cords that connect to transverse nerves. This arrangement allows for both cephalization (having a concentration of nerves in the head region) and centralization (having a centralized nervous system). Cnidarians also have a nerve net that enables some degree of coordination, but they lack an obvious concentration of nerves in the head region, which is necessary for true cephalization. Sponges and echinoderms have no centralized nervous system.

The Simplest Animals to Display Cephalization and Centralization of the Nervous