Chapter 21, Problem 5WIO

Summary Introduction

To discuss:

The arguments that support or refute the statement “Annelids are more closely related to flatworms than to roundworms”.

Concept Introduction:

Flatworms, annelids and roundworms all are included under the group eumetazoans characterized by bilateral symmetry and three germ layers. Flatworms and annelids are included under the class lophotrochozoa while roundworm comes under the class ecdysozoa. All the three group of animals have same characteristics feature which shows close relationship between them.