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True/False
Indicate whether the sentence or statement is true
or false.
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1.
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Mollusks must eat constantly because the functioning of their nephridia causes the
disposal of useful molecules as well as of waste products.
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2.
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Unlike arthropods, mollusks are unsegmented; instead, they are divided into three
regions.
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3.
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Mollusks have four distinct body parts: a foot, a head, a visceral mass, and a
tail.
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4.
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In
terrestrial snails, the mantle cavity functions as a simple lung.
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5.
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Most
bivalves have separate sexes, but some are hermaphroditic.
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6.
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Due
to the presence of a shell, all gastropods are capable of living on land for at least a portion of
their lives.
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7.
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Since
cephalopods have tentacles, they have no need for a radula.
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Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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8.
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All
of the following are characteristics of mollusks except that they have a. | a
pseudocoelomate body plan. | c. | a complete
digestive tract. | b. | bilateral symmetry. | d. | an open circulatory system. | | | | |
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9.
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The
cilia of a trochophore larva a. | allow attachment to the ocean bottom. | b. | create currents
for drawing in food. | c. | cover the entire larval body. | d. | are necessary
for reproduction. | | |
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10.
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Trochophore larvae a. | are found in molluscan life cycles. | b. | possess a belt
of cilia around their bodies. | c. | occur in annelid life cycles. | d. | All of the
above | | |
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11.
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A
characteristic structure found in many mollusks is the radula, which is involved in a. | jet
propulsion. | c. | eating. | b. | opening and closing of the
shells. | d. | reproduction. | | | | |
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12.
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All
of the following are classes of the phylum Mollusca except a. | bivalves. | c. | gastropods. | b. | cephalopods. | d. | pseudopods. | | | | |
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13.
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The
only mollusks that have a closed circulatory system are a. | bivalves. | c. | chitons. | b. | cephalopods. | d. | gastropods. | | | | |
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14.
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Refer
to the illustration above. Which two organisms in the diagrams possess mantles? a. | Organisms
“A” and “C” | c. | Organisms
“A” and “D” | b. | Organisms “B” and
“C” | d. | Organisms
“B” and “D” | | | | |
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15.
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“Jet propulsion” is the usual means of locomotion in water
for a. | arthropods. | c. | cephalopods. | b. | echinoderms. | d. | annelids. | | | | |
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16.
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Refer
to the illustration above. The organism shown in this diagram is a a. | bivalve. | c. | chiton. | b. | cephalopod. | d. | gastropod. | | | | |
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17.
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Refer
to the illustration above. This organism possesses a(n) a. | simple
lung. | c. | internal
beak. | b. | closed circulatory system. | d. | open circulatory system. | | | | |
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18.
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Refer
to the illustration above. Movement of this organism is dependent upon the structure
labeled a. | “1.” | c. | “3.” | b. | “2.” | d. | None of the above | | | | |
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19.
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Shells of mollusks a. | may consist of one or more
pieces. | c. | allow for the
attachment of muscles. | b. | provide protection. | d. | All of the above | | | | |
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20.
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Adductor muscles are responsible for a. | moving the
valves of bivalves. | c. | pumping the
hearts of mollusks. | b. | extending the feet of mollusks. | d. | fanning the gills of aquatic
mollusks. | | | | |
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