Ch 16

Question 1

All of the following are characteristics of members of the phylum Echinodermata except one. Select the exception.

Answer 1

larvae with radial symmetry

Question 2

A sieve-like plate that serves as an opening of a sea star’s water vascular system to the outside is called the

Answer 2

madreporite

Question 3

______ are canals of the water vascular system that run the length of the arms of star-shaped echinoderms.

Answer 3

Radial canals

Question 4

Which of the following phyla contains animals that are protostomes?

Answer 4

Annelida

Question 5

The following are functions served by echinoderm water vascular systems except one. Select the exception.

Answer 5

storage of gametes

Question 6

Sea stars belong to the class

Answer 6

Asteroidea

Question 7

Sand dollars belong to the class

Answer 7

Echinoidea

Question 8

Sea cucumbers belong to the class

Answer 8

Holothuroidea

Question 9

Sea lilies and feather stars belong to the class

Answer 9

Crinoidea

Question 10

A sea star feeds on a bivalve by everting the _______ into the shell of a bivalve and releasing digestive enzymes from the _____________.

Answer 10

oral stomach/pyloric cecae

Question 11

Members of the class ______ are predators and scavengers. They use their arms and tube feet in sweeping motions to collect prey and particulate matter. Their arms are sharply set off from the central disk.

Answer 11

Ophiuroidea

Question 12

A chewing apparatus found in members of the class Echinoidea is

Answer 12

Aristotle’s lantern.

Question 13

______ are a pair of tubes that attach to the rectum and branch throughout the body cavity of members of the class Holothuroidea.

Answer 13

Respiratory trees

Question 14

A “mouth-up” feeding posture is found in members of the class

Answer 14

Crinoidea.

Question 15

Of all living echinoderms, members of the class ______ most closely resemble the oldest fossil echinoderms.

Answer 15

Crinoidea

Question 16

Echinoderms are most closely related to members of the phylum

Answer 16

Chordata

Question 17

The earliest echinoderm fossils are about __________________ years old.

Answer 17

600 million

Question 18

Which class of echinoderms have adults with secondary bilateral symmetry?

Answer 18

Holothuroidea

Question 19

The earliest function of the water vascular system of echinoderms was probably locomotion.

Answer 19

False

Question 20

Fossil records indicate that 12 of the 18 classes of echinoderms have gone extinct.

Answer 20

True

Question 21

Echinoderms have spiral, determinate cleavage.

Answer 21

False

Question 22

Even though modern echinoderm adults are pentaradially symmetrical, ancestral echinoderms were probably bilaterally symmetrical.

Answer 22

True

Question 23

Sea stars are monoecious, and external fertilization results in the formation of bipinaria and brachiolaria larvae that crawl on the ocean floor.

Answer 23

False

Question 24

Members of the class Holothuroidea possess ossicles that are embedded in the dermis.

Answer 24

True

Question 25

The fact that most modern echinoderms are predators or scavengers means that ancestral echinoderms were also predators or scavengers.

Answer 25

False

Question 26

The ophiopluteus is a planktonic larval stage produced by members of the class Holothuroidea.

Answer 26

False

Question 27

The tentacles of a sea cucumber are used in feeding and branch from radial canals of the water vascular system.

Answer 27

True

Question 28

A brittle star, if grasped by an arm, may contract muscles that cause the arm to be severed. This process is called autotomy.

Answer 28

True

Question 29

The presence of suckers on the tube feet of many echinoderms is a derived character that was probably associated with a change from a sedentary, filter-feeding lifestyle to a more active existence.

Answer 29

True

Question 30

All crinoids are attached permanently to the substrate by a stalk of ossicles.

Answer 30

False