Chapter 30.5, Problem 1R

Summary Introduction

To review:

The basis of the independent evolution of the nervous system in ctenophores, cnidarians, and bilaterians.

Introduction:

Ctenophores are primitive marine animals consisting of colloblasts in their tentacles and eight rows of cilia all over their body. Cnidarians are a group of animals that possesses cnidocytes in their tentacles and display two distinct body forms. Bilaterians are triploblastic animals with bilateral body symmetry with simple to complex body organization.