Zoology Ch. 38-1 Study Guide

Home , Lancelet

Name ______Date ______Class ______

SHORT ANSWER Answer the questions in the space provided.

1. How do sea stars reproduce sexually? ______

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2. Describe the organization of a sea star’s nervous system. ______

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3. What do the larvae of echinoderms indicate about the evolution of echinoderms? ______

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4. Name the class of each of the following echinoderms: basket star, sea star, feather star, brittle star. ______

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5. How do sea stars use their ability to regenerate as a defensive mechanism? ______

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6. Critical Thinking Why is the lack of cephalization not a disadvantage for a sea star?______

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STRUCTURES AND FUNCTIONS Identify the structures labeled a–f in the drawing of part of a sea star

shown below.

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 8. Sexual reproduction among sea stars usually involves a. hermaphrodites and external c. separate sexes and external fertilization fertilization b. hermaphrodites and internal d. separate sexes and internal fertilization fertilization

____ 9. Both echinoderms and chordates a. are deuterostomes. c. have bilateral symmetry as adults. b. have radially symmetrical larvae. d. lack a coelom.

____ 10. Members of the class Echinoidea include a. sea urchins c. sea cucumbers b. sea lilies. d. sea stars

____ 11. One characteristic that is found only in echinoderms is a. an endoskeleton. c. a nerve net. b. a water-vascular system. d. the presence of only two tissue layers during development.

____ 12. The surface that is opposite the mouth in a sea star is called the a. posterior surface c. oral surface b. aboral surface d. dorsal surface

VOCABULARY REVIEW Explain the relationship between the terms in each of the following pairs of

terms.

13. water-vascular system, radial canal ______

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14. ossicle, test ______

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15. tube foot, ampulla ______

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16. cardiac stomach, pyloric stomach ______

Zoology Ch. 38-2 Study Guide

Short Answer

1. What behavior do tunicates exhibit when touched? ______

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2. How do lancelets use their tail? ______

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3. How does the structure of a larval tunicate differ from that of an adult tunicate? ______

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4. How did tunicates receive their name? ______

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5. List the chordate characteristics that lancelets have as adults. ______

______

6. Critical Thinking How are most adult tunicates similar to sponges, and how are they different from sponges? ______

______

STRUCTURES AND FUNCTIONS Identify the structures labeled a–f in the diagram of a lancelet shown

below.

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 8. In most chordates, the function of the notochord is taken over by the a. pharynx c. vertebral column b. brain d. spinal cord

____ 9. Animals in the subphyla Cephalochordata and Urochordata live a. only on land c. only in fresh water b. only in the ocean d. in fresh water, in the ocean, and on land

____ 10. Unlike adult lancelets, adult tunicates a. are radially symmetrical c. have segmented muscles in their tail b. have separate sexes d. are usually sessile

____ 11. The gill chambers of aquatic chordates evolved from the a. backbone c. postanal tail b. dorsal nerve cord d. pharyngeal pouches

____ 12. A lancelet feeds by a. filtering food particles from the water c. sucking blood from the skin of a larger that passes through its pharynx animal b. pursuing and capturing small animals d. digesting nutrients contained in the with its tentacles bottom sediments it swallows

VOCABULARY REVIEW Define the following terms.

13. notochord ______

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14. atriopore ______

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15. lancelet ______

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16. tunicate ______