Chapter 33

A land snail, a clam, and an octopus all share \begin{equation}\begin{array}{l}{\text { (A) a mantle. }} \\ {\text { (B) a radula. }} \\ {\text { (C) gills. }} \\ {\text { (D) distinct cephalization. }}\end{array}\end{equation}

. Which phylum is characterized by animals that have a segmented body? \begin{equation}\begin{array}{ll}{\text { (A) Cnidaria }} & {\text { (C) Arthropoda }} \\ {\text { (B) Platyhelminthes }} & {\text { (D) Mollusca }}\end{array}\end{equation}

The water vascular system of echinoderms \begin{equation}\begin{array}{l}{\text { (A) functions as a circulatory system that distributes nutrients }} \\ {\text { to body cells. }} \\ {\text { (B) functions in locomotion and feeding. }} \\ {\text { (C) is bilateral in organization, even though the adult animal }} \\ {\text { is not bilaterally symmetrical. }} \\ {\text { (D) moves water through the animal's body during filter feeding. }}\end{array}\end{equation}

. Which of the following combinations of phylum and description is incorrect? \begin{equation}\begin{array}{l}{\text { (A) Echinodermata - bilateral symmetry as a larva, coelomate }} \\ {\text { (B) Nematoda-roundworms, pseudocoelomate }} \\ {\text { (C) Platyhelminthes- flatworms, gastrovascular cavity, }} \\ {\text { acoelomate }} \\ {\text { (D) Porifera-gastrovascular cavity, coelomate }}\end{array}\end{equation}

WRITE ABOUT A THEME: ORGANIZATION Write a short essay \((100-150\) words) that explains how the structure of the digestive tract in different invertebrate groups affects the size of the organisms that they can eat.