Chapter 11 Flashcards
All of the following are unique to the molluscs except one. Select the exception.
shell
Which of the following is true of the radula of most molluscs?
It is used in rasping food.
The mantle of most molluscs
secretes the shell.
Which of the following is true of the mantle cavity of a bivalve?
It is the area where water circulates during feeding and gas exchange.
The molluscs are most closely related to the
other lophotrochozoans
Which of the following is true of the visceral mass of a mollusc?
It contains gonads and digestive glands.
Molluscs can be characterized by:
trochophore larvae and they are lophotrochozoans.
All of the following mollusc characters would be found in a member of the class Bivalvia except one. Select the exception.
radula
Members of which of the following mollusc classes would be characterized by a shell consisting of 8 plates?
Polyplacophora
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?
Scaphopoda
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.
Cephalopoda
______ is a developmental process that occurs in gastropods and results in a 180 degree counterclockwise twisting of the visceral mass and mantle cavity.
Torsion
A ______ is a mucoid mass that extends to the stomach of gastropods. It contains trapped food particles and is rotated by cilia.
protostyle
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
pneumostome
Water exits the mantle cavity of a bivalve through the ______ and the excurrent opening.
suprabranchial chamber
A ______ is a developmental stage of a freshwater bivalve that is parasitic on fishes.
glochidium
Which type of cephalopod possesses an external shell?
nautilus
Which of the following is generally accepted as the prevailing explanation behind the evolution of intelligence in cephalopods?
living as active predators as well as actively avoiding predators
Members of the classes Cephalopoda and Scaphopoda are the only molluscs that possess closed circulatory systems.
False
Cephalopods rely on olfactory senses for detecting prey.
False
Members of the class Polyplacophora include the chitons, which are found on hard substrates in marine habitats.
False
Most bivalves are dioecious.
True
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.
False
Labial palps of bivalves sort filtered food particles delivered by cilia lining the ventral margin of the gills.
True