Echinoderms and Invertebrate Chordates

Name Class Date Skills Worksheet Echinoderms and Invertebrate Chordates

Write the correct term from the list below in the space next to its definition. atriopore ossicles tube foot echinoderm test water-vascular system

______1. opening by which water leaves the body of a lancelet

______2. extension of the water-vascular system that aids movement

______3. group of invertebrates that includes sea stars, sand dollars, sea urchins, and sea cucumbers

______4. calcium-rich plates that make up the endoskeleton of an echinoderm

______5. a water-filled system of interconnected canals and thousands of tiny, hollow tube feet

______6. fused, rigid endoskeleton

In the space provided, write the letter of the description that best matches the term or phrase.

______7. pedicellaria a. contracts and forces water into the tube feet ______8. radial canal b. bilaterally symmetrical larva ______9. ampulla c. keeps the body free of foreign objects ______10. bipinnaria d. carries water directly to the tube feet

In the space provided, write the letter of the description that best matches the term or phrase.

______1. madreporite a. a chordate that lacks a nerve cord as an adult ______2. tunicate b. an armless echinoderm with protruding ______3. incurrent siphon spines c. an armless echinoderm with a soft, ______postanal tail 4. sluglike body ______5. sea cucumber d. the structure through which water enters a tunicate’s body ______6. sea urchin e. a structure that extends beyond the anus f. the structure through which water enters and leaves the water-vascular system

In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question.

______7. Most adult echinoderms have which of the following? a. an asymmetrical body b. five-part radial symmetry c. five-part bilateral symmetry d. two-part bilateral symmetry

______8. Sea lilies and feather stars differ from all other living echinoderms because their mouth a. develops from the blastopore. b. is disk-shaped. c. is located on the lower surface. d. is located on the upper surface.

______9. Which of the following is a sessile chordate? a. sea star c. lancelet b. tunicate d. sand dollar

______10. Animals that have a notochord but do NOT have a backbone are called a. protostomes. c. vertebrates. b. echinoderms. d. invertebrate chordates.