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.
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. 6.
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. 7.
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 8.
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 9.
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 10.
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 11.
______ 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 12.
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 13.
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. 14.
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 15.
A ______ is a developmental stage of a freshwater bivalve that is parasitic on fishes.A) veliger B) trochophore C) planula D) glochidium 16.
Which type of cephalopod possesses an external shell?A) cuttlefish B) nautilus C) squid D) octopus 17.
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 18.
Members of the classes Cephalopoda and Scaphopoda are the only molluscs that possess closed circulatory systems.A) True B) False 19.
Cephalopods rely on olfactory senses for detecting prey.A) True B) False 20.
Members of the class Polyplacophora include the chitons, which are found on hard substrates in marine habitats.A) True B) False 21.
Most bivalves are dioecious.A) True B) False 22.
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 23.
Labial palps of bivalves sort filtered food particles delivered by cilia lining the ventral margin of the gills.A) True B) False 24.
The operculum aids in both respiration and reproduction in gastropods.A) True B) False 25.
The Gastropoda and the Cephalopoda form a clade characterized by a dorsoventrally elongate body and shell coiling.A) True B) False 26.
The diversity of body forms and lifestyles present in the phylum Mollusca is an excellent example of adaptive radiation.A) True B) False 27.
Fertilization in bivalves is typically internal.A) True B) False 28.
Pearl formation may occur in bivalves when an irritant becomes lodged between the shell and the mantle. The mantle secretes nacre around the irritant, gradually forming a pearl.A) True B) False 29.
The class _______ is the largest and most varied molluscan class.A) Bivalvia B) Cephalopoda C) Gastropoda D) Polyplacophora