Animal Diversity

Chapter Introduction

Lesson 1: What defines an animal?

Lesson 2: Invertebrate Phyla

Lesson 3: Phylum Chordata

Chapter Wrap-Up

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CHAPTER INTRODUCTION

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What are the major groups of animals, and how do they differ?

Animal Diversity

CHAPTER INTRODUCTION

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Are these animals?

Look at the photo at the beginning of the chapter. What are the blue structures attached to these underwater rocks? Did someone spill paint on a clump of algae? This is a colony of animals called tunicates (TEW nuh kayts), also know as sea squirts. Believe it or not, they are classified in the same phylum as humans.

• What characteristics do you think tunicates have in common with other animals?
• How do tunicates differ from other animals?

Animal Diversity

CHAPTER INTRODUCTION

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Animal Diversity

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Begin the lesson presentations for this chapter�before returning to the Chapter Wrap-Up.

What are the major groups of animals, and how do they differ?

The major groups of animals include sponges, cnidarians, flatworms, roundworms, mollusks, segmented worms, arthropods, and chordates. They differ based on body structures and types of reproduction.

Animal Diversity

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CHAPTER WRAP-UP

Lesson 1: What defines an animal?

• Animals are eukaryotic, multicellular organisms that eat other organisms, digest food, and have collagen to support cells. Most animals reproduce sexually and can move.
• Animals can be classified based on the presence of a backbone; body symmetry; the characteristics of proteins, DNA, and other molecules that make up their cells; and the kinds of body structures they possess.

Animal Diversity

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CHAPTER WRAP-UP

Lesson 2: Invertebrate Phyla

• Invertebrates have no backbone or internal skeleton, and they tend to be smaller and slower-moving than vertebrates.
• Invertebrates differ based on symmetry, presence or absence of certain types of specialized body structures, and presence or absence of specific internal organs and organ systems.

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Lesson 3: Phylum Chordata

• All chordates have a notochord, a central nerve cord, pharyngeal pouches, and a tail at some time during their development.
• All vertebrates have a backbone and well-developed organs and organ systems.
• The classes of vertebrates differ based on presence or absence of characteristics such as gills, fins, scales, legs, wings, fur, and eggs.

Animal Diversity

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CHAPTER WRAP-UP