1.
All of the following are unique to the molluscs except one. Select the exception.A) mantle B) shell C) visceral mass D) head-foot 2.
Which of the following is true of the radula of most molluscs?A) It is used in reproduction. B) It is used in excretion. C) It is used in rasping food. D) It is used in gas exchange. 3.
The mantle of most molluscsA) is modified for locomotion. B) is used in attracting prey. C) secretes the shell. D) supports the radula. 4.
Which of the following is true of the mantle cavity of a bivalve?A) It is the area where water circulates during feeding and gas exchange. B) It is the space between the mantle and the shell. C) It is the space between the pericardium and the heart. D) It is the space where blood circulates before being returned to the heart. 5.
The molluscs are most closely related to theA) other lophotrochozoans B) echinoderms. C) other edysozoans. D) chordates. 6.
Which of the following is true of the visceral mass of a mollusc?A) It contains the gills. B) It secretes the shell. C) It is used in locomotion. D) It contains gonads and digestive glands. 7.
Molluscs can be characterized by:A) trochophore larvae, and they are deuterostomes. B) planala larvae, and they are ecdysozoans. C) trochophore larvae and they are lophotrochozoans. D) planula larvae, and they are deuterostomes. 8.
All of the following mollusc characters would be found in a member of the class Bivalvia except one. Select the exception.A) visceral mass B) head-foot C) mantle cavity D) radula 9.
Members of which of the following mollusc classes would be characterized by a shell consisting of 8 plates?A) Aplacophora B) Polyplacophora C) Monoplacophora D) Cephalopoda 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?A) Scaphopoda B) Bivalvia C) Polyplacophora D) Gastropoda 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.A) Aplacophora B) Polyplacophora C) Monoplacophora D) Cephalopoda 12.
______ is a developmental process that occurs in gastropods and results in a 180 degree counterclockwise twisting of the visceral mass and mantle cavity.A) Gastrulation B) Epiboly C) Involution D) Torsion 13.
A ______ is a mucoid mass that extends to the stomach of gastropods. It contains trapped food particles and is rotated by cilia.A) protostyle B) umbo C) crystalline style D) gastric shield 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/anA) siphon. B) pneumostome. C) umbo. D) operculum. 15.
Water exits the mantle cavity of a bivalve through the ______ and the excurrent opening.A) water tube B) incurrent opening C) suprabranchial chamber D) pericardial cavity 16.
A ______ is a developmental stage of a freshwater bivalve that is parasitic on fishes.A) veliger B) trochophore C) planula D) glochidium 17.
Which type of cephalopod possesses an external shell?A) cuttlefish B) nautilus C) squid D) octopus 18.
Which of the following is generally accepted as the prevailing explanation behind the evolution of intelligence in cephalopods?A) their complex social structure B) the fact that they typically live long lives C) living as active predators as well as actively avoiding predators D) the pressures exerted by living in both marine and freshwater environments 19.
Members of the classes Cephalopoda and Scaphopoda are the only molluscs that possess closed circulatory systems.A) True B) False 20.
Cephalopods rely on olfactory senses for detecting prey.A) True B) False 21.
Members of the class Polyplacophora include the chitons, which are found on hard substrates in marine habitats.A) True B) False 22.
Most bivalves are dioecious.A) True B) False 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.A) True B) False 24.
Labial palps of bivalves sort filtered food particles delivered by cilia lining the ventral margin of the gills.A) True B) False 25.
The operculum aids in both respiration and reproduction in gastropods.A) True B) False 26.
The Gastropoda and the Cephalopoda form a clade characterized by a dorsoventrally elongate body and shell coiling.A) True B) False 27.
The diversity of body forms and lifestyles present in the phylum Mollusca is an excellent example of adaptive radiation.A) True B) False 28.
The absence of a shell in the Aplacophora is a primitive character in the phylum Mollusca.A) True B) False 29.
Fertilization in bivalves is typically internal.A) True B) False