Chapter 11

Question 1

All of the following are unique to the molluscs except one. Select the exception.

Answer 1

shell

Question 2

Which of the following is true of the radula of most molluscs?

Answer 2

It is used in rasping food.

Question 3

The mantle of most molluscs

Answer 3

secretes the shell.

Question 4

Which of the following is true of the mantle cavity of a bivalve?

Answer 4

It is the area where water circulates during feeding and gas exchange.

Question 5

The molluscs are most closely related to the

Answer 5

other lophotrochozoans

Question 6

Which of the following is true of the visceral mass of a mollusc?

Answer 6

It contains gonads and digestive glands.

Question 7

Molluscs can be characterized by:

Answer 7

trochophore larvae and they are lophotrochozoans.

Question 8

All of the following mollusc characters would be found in a member of the class Bivalvia except one. Select the exception.

Answer 8

radula

Question 9

Members of which of the following mollusc classes would be characterized by a shell consisting of 8 plates?

Answer 9

Polyplacophora

Question 10

Members of which of the following mollusc classes would be characterized by a reduced head, a mantle that surrounds the entire body and a tusk-shaped shell?

Answer 10

Scaphopoda

Question 11

Members of which of the following mollusc clases would be characterized by their complex nervous sytems, a head in line with the visceral mass, and a closed circulatory system.

Answer 11

Cephalopoda

Question 12

______ is a developmental process that occurs in gastropods and results in a 180 degree counterclockwise twisting of the visceral mass and mantle cavity.

Answer 12

Torsion

Question 13

A ______ is a mucoid mass that extends to the stomach of gastropods. It contains trapped food particles and is rotated by cilia.

Answer 13

protostyle

Question 14

Members of the gastropod subclass Pulmonata are predominantly freshwater or terrestrial. Their mantle is modified into a lung, which opens to the outside of the mantle cavity through a/an

Answer 14

pneumostome

Question 15

Water exits the mantle cavity of a bivalve through the ______ and the excurrent opening.

Answer 15

suprabranchial chamber

Question 16

A ______ is a developmental stage of a freshwater bivalve that is parasitic on fishes.

Answer 16

glochidium

Question 17

Which type of cephalopod possesses an external shell?

Answer 17

nautilus

Question 18

Which of the following is generally accepted as the prevailing explanation behind the evolution of intelligence in cephalopods?

Answer 18

living as active predators as well as actively avoiding predators

Question 19

Members of the classes Cephalopoda and Scaphopoda are the only molluscs that possess closed circulatory systems.

Answer 19

False

Question 20

Cephalopods rely on olfactory senses for detecting prey.

Answer 20

False

Question 21

Members of the class Polyplacophora include the chitons, which are found on hard substrates in marine habitats.

Answer 21

False

Question 22

Most bivalves are dioecious.

Answer 22

True

Question 23

Members of the class Monoplacophora are wormlike molluscs that lack a shell, crystalline style, and foot; they live in vertical burrows on the deep-sea floor.

Answer 23

False

Question 24

Labial palps of bivalves sort filtered food particles delivered by cilia lining the ventral margin of the gills.

Answer 24

True

Question 25

The operculum aids in both respiration and reproduction in gastropods.

Answer 25

False

Question 26

The Gastropoda and the Cephalopoda form a clade characterized by a dorsoventrally elongate body and shell coiling.

Answer 26

True

Question 27

The diversity of body forms and lifestyles present in the phylum Mollusca is an excellent example of adaptive radiation.

Answer 27

True

Question 28

The absence of a shell in the Aplacophora is a primitive character in the phylum Mollusca.

Answer 28

True

Question 29

Fertilization in bivalves is typically internal.

Answer 29

False