Question 1

The main structures that taste food and direct it into the mouth of a clam is/are

Accepted Answer

A)  the gills. 
B)  labial palps. 
C)  the siphons. 
D)  the gastric mill. 
E)  adductor muscles. 
A)  the gills. 
B)  labial palps. 
C)  the siphons. 
D)  the gastric mill. 
E)  adductor muscles.

Question 2

The ________ _________ projects into a bivalve stomach to keep the contents whirling while releasing digestive enzymes.

Accepted Answer

The answer of The ________ _________ projects into a bivalve...

Question 3

To prevent taking back in the wastes it has just expelled,a standard sediment-inhabiting bivalve mollusk should position itself

Accepted Answer

A)  with the incurrent siphon upstream. 
B)  with the excurrent siphon upstream. 
C)  in any direction, since it can control which way the water flows in either siphon. 
D)  either with the incurrent siphon upstream or with the excurrent siphon upstream, but not in any direction, since it can control which way the water flows in either siphon. 
E)  None of the choices are correct 
A)  with the incurrent siphon upstream. 
B)  with the excurrent siphon upstream. 
C)  in any direction, since it can control which way the water flows in either siphon. 
D)  either with the incurrent siphon upstream or with the excurrent siphon upstream, but not in any direction, since it can control which way the water flows in either siphon. 
E)  None of the choices are correct

Question 4

The radula

Accepted Answer

A)  not only rasps off fine food particles but also serves as a conveyor belt to carry food toward the digestive tract. 
B)  replaces worn teeth by secreting new teeth at the posterior end. 
C)  varies in number, pattern, and form of teeth, allowing species to be classified by this trait. 
D)  may be modified to bore through hard materials. 
E)  All of the choices are correct 
A)  not only rasps off fine food particles but also serves as a conveyor belt to carry food toward the digestive tract. 
B)  replaces worn teeth by secreting new teeth at the posterior end. 
C)  varies in number, pattern, and form of teeth, allowing species to be classified by this trait. 
D)  may be modified to bore through hard materials. 
E)  All of the choices are correct

Question 5

Cephalopod eyes and vertebrate eyes are anatomically similar. Evaluate whether or not the similarity is a case of homology or analogy. State your reasoning.

Accepted Answer

The similarity between cephalopod eyes a

Question 6

The internal organs in coelomates are covered with a mesodermal epithelium called the _______________.

Accepted Answer

The answer of The internal organs in coelomates are covered...

Question 7

How do you account for the enormous radiation of the molluscs? Give factual support for your answer.

Accepted Answer

The enormous radiation of molluscs can b

Question 8

Cephalopods feed on

Accepted Answer

A)  microscopic organisms. 
B)  fish, molluscs, crustaceans, and worms. 
C)  seaweed. 
D)  whales and porpoises. 
E)  None of the choices are correct 
A)  microscopic organisms. 
B)  fish, molluscs, crustaceans, and worms. 
C)  seaweed. 
D)  whales and porpoises. 
E)  None of the choices are correct

Question 9

The circulatory system of cephalopods is more efficient than that of other molluscs because

Accepted Answer

A)  it places the systemic circulation before the gills. 
B)  it is a closed network of vessels. 
C)  all blood is circulated through the gill filaments. 
D)  accessory or brachial hearts increase blood pressure before blood flows through the gills. 
E)  All of the choices are correct 
A)  it places the systemic circulation before the gills. 
B)  it is a closed network of vessels. 
C)  all blood is circulated through the gill filaments. 
D)  accessory or brachial hearts increase blood pressure before blood flows through the gills. 
E)  All of the choices are correct

Question 10

Snails were discovered in the Negev desert at night,harvesting the lichens that grew in the moist pores of the limestone and wearing down the desert more than abrasion from wind.Scientists studying these snails added mild acid to the snail feces and it foamed; this was an important test to detect that

Accepted Answer

A)  the snails digested and derived nutrition from breakdown of the limestone rock. 
B)  the snail was excreting uric acid. 
C)  some limestone was actually scraped off and ingested with the lichen. 
D)  the lichen had some food value. 
E)  not all food was digested. 
A)  the snails digested and derived nutrition from breakdown of the limestone rock. 
B)  the snail was excreting uric acid. 
C)  some limestone was actually scraped off and ingested with the lichen. 
D)  the lichen had some food value. 
E)  not all food was digested.

Question 11

Among living molluscs,the ancestral condition is most nearly approached by the class _____________.

Accepted Answer

The answer of Among living molluscs,the ancestral condition is most...

Question 12

Most cephalopods have an ink gland that secretes ______________,a dark fluid containing melanin,to confuse enemies.

Accepted Answer

The answer of Most cephalopods have an ink gland that...

Question 13

Scaphopods have a captacula or head with long tentacles; how do they differ from the tentacles of cephalopods? Are these two types of tentacles homologous?

Accepted Answer

Scaphopods, commonly known as tusk shell

Question 14

What are the morphological features that distinguish the ammonoids from the nautiloids?

Accepted Answer

Ammonoids and nautiloids are both cephal

Question 15

Which correctly describes the evolutionary origin and adaptive radiation of molluscs?

Accepted Answer

A)  Molluscs originated in freshwater and invaded both terrestrial and marine environments 
B)  Molluscs originated on land, all classes then invaded both freshwater and marine environments 
C)  Molluscs originated on land, all classes then invaded freshwater and the bivalves and gastropods invaded marine environments 
D)  Molluscs originated in the sea, both bivalves and gastropods invaded marine environments and the land 
E)  Molluscs originated in the sea, bivalves and gastropods invaded brackish and freshwater environments, and just gastropods invaded the land 
A)  Molluscs originated in freshwater and invaded both terrestrial and marine environments 
B)  Molluscs originated on land, all classes then invaded both freshwater and marine environments 
C)  Molluscs originated on land, all classes then invaded freshwater and the bivalves and gastropods invaded marine environments 
D)  Molluscs originated in the sea, both bivalves and gastropods invaded marine environments and the land 
E)  Molluscs originated in the sea, bivalves and gastropods invaded brackish and freshwater environments, and just gastropods invaded the land

Question 16

Clams burrow by using

Accepted Answer

A)  adductor muscles. 
B)  cilia action. 
C)  gills for jet propulsion. 
D)  a modified radula. 
E)  a foot. 
A)  adductor muscles. 
B)  cilia action. 
C)  gills for jet propulsion. 
D)  a modified radula. 
E)  a foot.

Question 17

Give the supporting evidence that shows that the molluscs share a common ancestor with the annelids.

Accepted Answer

Molluscs and annelids are both part of t

Question 18

Of all of the freshwater organisms,more freshwater clams are becoming endangered than other species.What is the likely reason?

Accepted Answer

A)  They are a primitive animal and they are due for natural extinction 
B)  The shellfish industry has moved inland and we are overharvesting them for human food 
C)  Clams are more heavily parasitized than any other molluscan group 
D)  As filter-feeders, they concentrate pollutants and are more likely to be harmed by water pollution 
E)  All of the choices are correct 
A)  They are a primitive animal and they are due for natural extinction 
B)  The shellfish industry has moved inland and we are overharvesting them for human food 
C)  Clams are more heavily parasitized than any other molluscan group 
D)  As filter-feeders, they concentrate pollutants and are more likely to be harmed by water pollution 
E)  All of the choices are correct

Question 19

In some molluscs,the free-swimming larva is a trochophore while in others,it is a veliger with the beginnings of a foot,shell and mantle.What is the relationship of these molluscan juvenile stages?

Accepted Answer

A)  A veliger is found strictly in terrestrial molluscs 
B)  The trochophore is considered ancestral and the veliger is a derived larval stage 
C)  The two larval forms represent two early and distinct branches of molluscs 
D)  The veliger is ancestral and the trochophore is a derived larval stage 
E)  Only the cephalopods have the veliger stage; all other molluscs have a trochophore stage 
A)  A veliger is found strictly in terrestrial molluscs 
B)  The trochophore is considered ancestral and the veliger is a derived larval stage 
C)  The two larval forms represent two early and distinct branches of molluscs 
D)  The veliger is ancestral and the trochophore is a derived larval stage 
E)  Only the cephalopods have the veliger stage; all other molluscs have a trochophore stage

Exam 16: Molluscs

The main structures that taste food and direct it into the mouth of a clam is/are

The ________ _________ projects into a bivalve stomach to keep the contents whirling while releasing digestive enzymes.

To prevent taking back in the wastes it has just expelled,a standard sediment-inhabiting bivalve mollusk should position itself

The radula

Cephalopod eyes and vertebrate eyes are anatomically similar. Evaluate whether or not the similarity is a case of homology or analogy. State your reasoning.

The internal organs in coelomates are covered with a mesodermal epithelium called the _______________.

How do you account for the enormous radiation of the molluscs? Give factual support for your answer.

Cephalopods feed on

The circulatory system of cephalopods is more efficient than that of other molluscs because

Among living molluscs,the ancestral condition is most nearly approached by the class _____________.

Most cephalopods have an ink gland that secretes ______________,a dark fluid containing melanin,to confuse enemies.

Scaphopods have a captacula or head with long tentacles; how do they differ from the tentacles of cephalopods? Are these two types of tentacles homologous?

What are the morphological features that distinguish the ammonoids from the nautiloids?

Which correctly describes the evolutionary origin and adaptive radiation of molluscs?

Clams burrow by using

Give the supporting evidence that shows that the molluscs share a common ancestor with the annelids.

Of all of the freshwater organisms,more freshwater clams are becoming endangered than other species.What is the likely reason?

In some molluscs,the free-swimming larva is a trochophore while in others,it is a veliger with the beginnings of a foot,shell and mantle.What is the relationship of these molluscan juvenile stages?

Life: Biological Principles and the Science of Zoology

The Origin and Chemistry of Life

Cells As Units of Life

Cellular Metabolism

Genetics: a Review

Organic Evolution

The Reproductive Process

Principles of Development

Architectural Pattern of an Animal

Taxonomy and Phylogeny of Animals

Unicellular Eukaryotes

Sponges and Placozoans

Radiate Animals

Acoelomorpha,Platyzoa,and Mesozoa

Polyzoa and Kryptrochozoa

Annelids and Allied Taxa

Smaller Ecdysozoans

Trilobites, Chelicerates, and Myriapods

Crustaceans

Support, Protection, and Movement

Chaetognaths, Echinoderms, and Hemichordates

Chordates

Fishes

Early Tetrapods and Modern Amphibians

Amniote Origins and Nonavian Reptiles

Birds

Mammals

Support, protection, and Movement

Homeostasis: Osmotic Regulation, Excretion, and Temperature Regulation

Homeostasis: Internal Fluids and Respiration

Digestion and Nutrition

Nervous Coordination: Nervous System and Sense Organs

Chemical Coordination: Endocrine System

Immunity

Animal Behavior

Animal Distributions

Animal Ecology

Filters

The _ projects into a bivalve stomach to keep the contents whirling while releasing digestive enzymes.