Chapter 49.1, Problem 2R

Summary Introduction

To review:

The survival of small organisms such as sponges without the presence of a circulatory system.

Introduction:

Sponges are the invertebrate and multicellular organisms, which belongs to phylum Porifera. They are the simple marine animals with the presence of an opening called operculum through which the water enters into the body. They lack the presence of any specialized cells, organ or organ system.