Chapter 19, Problem 2TC

Summary Introduction

To explain:

The lifestyle differences between the bilateral symmetrical organism and radial symmetrical organism.

Given:

Animals such as cnidarians and many adult echinoderms can be divided into two equal halves by any plane. Some animals such as humans can be divided into two equal halves by only one plane.

Introduction:

Animals such as cnidarians (sea anemone) and adult echinoderms (starfish) have a radial body because their body can be divided into equal parts if cut from the center in any plane. These animals do not have right and left side or head and tail end. Animals with bilateral symmetry examples, housefly, and humans can be divided only into equal parts in only one plane. These animals have right and left side or head and tail end.