Chapter 33.1, Problem 1CC

Summary Introduction

To describe: The mode of nutrition in sponges.

Concept introduction: All sponges belong to a phylum called porifera. They are simplest animal with cellular level of organization. They have diverged from other animals early in the evolution. Hence, they are called as basal animals. They have a very simple body structure composed of only two layers of cells. In between the two layers, a gelatinous region is present called mesohyl. The exchange of nutrient and waste material take place through diffusion in sponges.