Question 1

Although snails and some other molluscs are hermaphroditic,most molluscs are either male or female,a condition called

Accepted Answer

A)  asexual. 
B)  sexual. 
C)  monoecious. 
D)  dioecious. 
E)  parthenogenetic. 
A)  asexual. 
B)  sexual. 
C)  monoecious. 
D)  dioecious. 
E)  parthenogenetic.

Question 2

The _________ is the oldest part of the shell and growth occurs in concentric rings around it.

Accepted Answer

The answer of The _________ is the oldest part of...

Question 3

When cephalopods hatch from their eggs,they are

Accepted Answer

A)  trochophore larvae. 
B)  glochidial parasites. 
C)  helpless, sessile larvae that must metamorphose into adult forms. 
D)  juveniles that resemble small adults. 
E)  There is much variation and all of the above occur among the various cephalopods 
A)  trochophore larvae. 
B)  glochidial parasites. 
C)  helpless, sessile larvae that must metamorphose into adult forms. 
D)  juveniles that resemble small adults. 
E)  There is much variation and all of the above occur among the various cephalopods

Question 4

The Polyplacophora

Accepted Answer

A)  have a coiled shell. 
B)  live in the ocean, especially in intertidal areas. 
C)  lack gills. 
D)  lack a radula. 
E)  All of the choices are correct 
A)  have a coiled shell. 
B)  live in the ocean, especially in intertidal areas. 
C)  lack gills. 
D)  lack a radula. 
E)  All of the choices are correct

Question 5

Which of the following statements is NOT TRUE of cephalopods?

Accepted Answer

A)  Most have color vision 
B)  Visual acuity underwater surpasses that of humans 
C)  Can be taught to discriminate between shapes 
D)  Sensory systems are more elaborate than in other molluscs 
E)  Brain is the largest of any invertebrate 
A)  Most have color vision 
B)  Visual acuity underwater surpasses that of humans 
C)  Can be taught to discriminate between shapes 
D)  Sensory systems are more elaborate than in other molluscs 
E)  Brain is the largest of any invertebrate

Question 6

The solenogastres

Accepted Answer

A)  live free on the sea bottom and feed on cnidarians. 
B)  have a shell of eight articulating plates. 
C)  resemble the squids. 
D)  are called chitons. 
E)  have the primitive radula and gill mollusc plan. 
A)  live free on the sea bottom and feed on cnidarians. 
B)  have a shell of eight articulating plates. 
C)  resemble the squids. 
D)  are called chitons. 
E)  have the primitive radula and gill mollusc plan.

Question 7

The newest clam shell is built

Accepted Answer

A)  on the outside so the periostracum is the newest material. 
B)  on the inside so the inside nacreous layer is the newest. 
C)  both directions outward from the central prismatic layer. 
D)  all at once; all layers of shell are the same age. 
E)  None of the choices are correct 
A)  on the outside so the periostracum is the newest material. 
B)  on the inside so the inside nacreous layer is the newest. 
C)  both directions outward from the central prismatic layer. 
D)  all at once; all layers of shell are the same age. 
E)  None of the choices are correct

Question 8

The circulatory system of cephalopods is more efficient than other molluscs because it has accessory or ________ _______ at the base of each gill.

Accepted Answer

The answer of The circulatory system of cephalopods is more...

Question 9

A Nautilus differs from a snail because

Accepted Answer

A)  the snail body occupies the whole shell and the Nautilus mainly lives in the last chamber. 
B)  the Nautilus is the last representative of a once flourishing group while snails belong to a most abundant modern group. 
C)  the Nautilus generates gas in the chambers for buoyancy during swimming and a snail does not. 
D)  All of the choices are differences 
E)  None of the choices are correct 
A)  the snail body occupies the whole shell and the Nautilus mainly lives in the last chamber. 
B)  the Nautilus is the last representative of a once flourishing group while snails belong to a most abundant modern group. 
C)  the Nautilus generates gas in the chambers for buoyancy during swimming and a snail does not. 
D)  All of the choices are differences 
E)  None of the choices are correct

Question 10

The ______________ is the layer on the outside of the clam or mussel shell that provides protection from acidic water and may be colored to hide the clam in the mud.

Accepted Answer

The answer of The ______________ is the layer on the...

Question 11

Because shells require it,land snails are limited to soils that contain some level of

Accepted Answer

A)  aluminum. 
B)  silica. 
C)  calcium. 
D)  sodium. 
E)  carbon. 
A)  aluminum. 
B)  silica. 
C)  calcium. 
D)  sodium. 
E)  carbon.

Question 12

The cephalopod nervous system is best described as

Accepted Answer

A)  absent. 
B)  primitive and very little advanced from that of a cnidarian. 
C)  the most advanced among molluscs. 
D)  more complex than ours. 
E)  None of the choices are correct 
A)  absent. 
B)  primitive and very little advanced from that of a cnidarian. 
C)  the most advanced among molluscs. 
D)  more complex than ours. 
E)  None of the choices are correct

Question 13

How does torsion differ from coiling? Fully explain your answer.

Accepted Answer

Torsion and coiling are both methods of

Question 14

The shell of Polyplacophora is divided into _______ _______ valves.

Accepted Answer

The answer of The shell of Polyplacophora is divided into...

Question 15

Torsion

Accepted Answer

A)  involves movement of the shell independent of visceral movements. 
B)  rotates the shell between 90 and 180 degrees. 
C)  begins with the contraction of an asymmetrical foot retractor muscle. 
D)  shifts the anus from posterior to the right side of the body. 
E)  All of the choices are correct 
A)  involves movement of the shell independent of visceral movements. 
B)  rotates the shell between 90 and 180 degrees. 
C)  begins with the contraction of an asymmetrical foot retractor muscle. 
D)  shifts the anus from posterior to the right side of the body. 
E)  All of the choices are correct

Question 16

Some prosobranchs have only one _____________ in their mantle cavity.

Accepted Answer

A)  Shell 
B)  Foot 
C)  Gill 
D)  Radula 
E)  Tentacle 
A)  Shell 
B)  Foot 
C)  Gill 
D)  Radula 
E)  Tentacle

Question 17

Molluscs with a tubular shell that open at both ends are in the class _____________________.

Accepted Answer

The answer of Molluscs with a tubular shell that open...

Question 18

The Scaphopoda

Accepted Answer

A)  lack a shell. 
B)  lack a mantle. 
C)  live in fresh water. 
D)  pursue prey in a manner similar to squid. 
E)  lack gills. 
A)  lack a shell. 
B)  lack a mantle. 
C)  live in fresh water. 
D)  pursue prey in a manner similar to squid. 
E)  lack gills.

Question 19

The caudofoveates

Accepted Answer

A)  are mostly worm-like, burrowing, marine organisms. 
B)  possess an oral shield associated with food selection and intake. 
C)  possess a radula (reduced in some species). 
D)  may have more features in common with the common ancestor of all molluscs than any other living group. 
E)  All of the choices are correct 
A)  are mostly worm-like, burrowing, marine organisms. 
B)  possess an oral shield associated with food selection and intake. 
C)  possess a radula (reduced in some species). 
D)  may have more features in common with the common ancestor of all molluscs than any other living group. 
E)  All of the choices are correct

Question 20

The intromittent organ of male cephalopods is the

Accepted Answer

A)  pedipalp, a modified labial palp. 
B)  hectocotylus, a modified arm. 
C)  aedeagus, a modified beak. 
D)  penis, the first structure homologous to the mammalian reproductive structure. 
E)  baculum, a modified piece of internal shell. 
A)  pedipalp, a modified labial palp. 
B)  hectocotylus, a modified arm. 
C)  aedeagus, a modified beak. 
D)  penis, the first structure homologous to the mammalian reproductive structure. 
E)  baculum, a modified piece of internal shell.

Exam 16: Molluscs

Although snails and some other molluscs are hermaphroditic,most molluscs are either male or female,a condition called

The _________ is the oldest part of the shell and growth occurs in concentric rings around it.

When cephalopods hatch from their eggs,they are

The Polyplacophora

Which of the following statements is NOT TRUE of cephalopods?

The solenogastres

The newest clam shell is built

The circulatory system of cephalopods is more efficient than other molluscs because it has accessory or ________ _______ at the base of each gill.

A Nautilus differs from a snail because

The ______________ is the layer on the outside of the clam or mussel shell that provides protection from acidic water and may be colored to hide the clam in the mud.

Because shells require it,land snails are limited to soils that contain some level of

The cephalopod nervous system is best described as

How does torsion differ from coiling? Fully explain your answer.

The shell of Polyplacophora is divided into _______ _______ valves.

Torsion

Some prosobranchs have only one _____________ in their mantle cavity.

Molluscs with a tubular shell that open at both ends are in the class _____________________.

The Scaphopoda

The caudofoveates

The intromittent organ of male cephalopods is the

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The circulatory system of cephalopods is more efficient than other molluscs because it has accessory or __ _ at the base of each gill.

The shell of Polyplacophora is divided into _ _ valves.