Modified True/False (Value 10) Indicate whether the statement is true or false. If false,
change the identified word or phrase to make the statement true.
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1.
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Turbellaria is a class of parasitic flatworms.
_________________________
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2.
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The type of body cavity shared by all mollusks is a pseudocoelom.
_________________________
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3.
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Polychaetes are annelids that help aerate and mix layers of soil,
improving the soil’s quality. _________________________
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4.
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Undigested material leaves a roundworm’s body through the anus.
_________________________
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5.
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A flatworm’s eyespots can detect chemicals.
_________________________
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6.
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Mollusks are soft-bodied animals that usually have an internal or
external shell. _________________________
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7.
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In clams and oysters, two shells are held together by powerful muscles—a
trait common to all cephalopods. ____________________
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8.
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An unidentified worm specimen that has a one-way digestive tract suspended in a
pseudocoelom is likely to be a(an) annelid. _________________________
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9.
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Unlike most parasitic worms, polychaetes typically attach to their host
externally. _________________________
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10.
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Annelids and mollusks, both of which possess a coelom, may be more
closely related to each other than either is to flatworms or roundworms.
_________________________
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Completion (Value 5) Complete
each statement.
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11.
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Many free-living roundworms are ____________________, which are animals that eat
other animals.
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12.
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Sandworms and bloodworms are members of the class of marine annelids called
____________________.
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13.
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The primary host of Schistosoma mansoni is a(an)
_________________________.
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14.
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The type of embryonic tissue that lines a true coelom is called
____________________.
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15.
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The simplest animals to have three embryonic germ layers, bilateral symmetry,
and cephalization are the ____________________.
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Short Answer (Answer any 2 of 5) (Value 4)
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16.
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What role does diffusion play in the lives of roundworms and flatworms?
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17.
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What has happened to the internal shell of squids over evolutionary time?
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18.
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What are the four parts of the body plan of most mollusks?
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19.
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In what ways do earthworms improve soil quality?
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20.
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What is the meaning of the Latin word molluscus? Why is this meaning
appropriate for mollusks?
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Multiple Choice Answer 15 of the following 20 questions (Value 15) Identify the choice that best completes the statement or answers
the question.
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21.
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An adult tapeworm uses its scolex to
a. | store sperm. | b. | digest food. | c. | attach itself to the
intestinal wall of its host. | d. | store fertilized
eggs. |
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22.
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Which of these animals has a true coelom?
a. | planarian | c. | leech | b. | tapeworm | d. | filarial worm |
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23.
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The spade-shaped burrowing structure of one group of mollusks and the tentacles
of another group are both modifications of the
a. | shell. | c. | foot. | b. | visceral mass. | d. | mantle. |
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24.
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The larvae of many marine annelids are ecologically important because
they
a. | poison coral reefs. | b. | feed on earthworms. | c. | are eaten by fishes
and other marine animals. | d. | aerate the mud on the
seafloor. |
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25.
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Some mollusks are detritivores. Their main source of food comes
from
a. | bacteria in the muddy bottom. | c. | living animals. | b. | living
plants. | d. | decaying plant and
animal remains. |
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26.
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Roundworms have a digestive system
a. | with one opening. | c. | within a true coelom. | b. | with two
openings. | d. | that branches
into multiple passages. |
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27.
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What causes the disease called elephantiasis?
a. | ascarid worms | c. | filarial worms | b. | flukes | d. | hookworms |
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28.
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In an earthworm, the dorsal blood vessel functions like a heart because
it
a. | connects to sinuses. | c. | receives blood from gills. | b. | contracts and helps
pump blood. | d. | connects to
ring vessels. |
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29.
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The most active mollusks are the
a. | gastropods. | c. | cephalopods. | b. | bivalves. | d. | nudibranchs. |
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30.
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In a pseudocoelom, mesoderm partially lines the
a. | body cavity. | c. | germ layer. | b. | blood vessels. | d. | pharynx. |
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31.
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In earthworms, food is ground into small pieces in the
a. | gizzard. | c. | crop. | b. | pharynx. | d. | esophagus. |
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32.
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Mollusks have
a. | a true coelom. | b. | a body cavity between the ectoderm and
mesoderm. | c. | no body cavity. | d. | a pseudocoelom. |
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33.
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Why is an open circulatory system adequate for a bivalve, such as a clam, but
not for a cephalopod, such as a squid?
a. | Cephalopods have relatively low oxygen demands. | b. | Bivalves are largely
sedentary, while squids move quickly. | c. | Bivalves have relatively high oxygen
demands. | d. | Bivalves are filter-feeders, and cephalopods are plant
eaters. |
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34.
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Bivalve communities that live near undersea volcanic vents obtain their food
mostly from
a. | symbiotic bacteria. | c. | filter-feeding. | b. | detritus. | d. | symbiotic
algae. |
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35.
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Free-living flatworms, most of which live in marine environments or fresh water,
are
a. | roundworms. | c. | turbellarians. | b. | tapeworms. | d. | flukes. |
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36.
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The tubelike structure through which water enters and leaves a mollusk’s
body is the
a. | siphon. | c. | sinus. | b. | mantle cavity. | d. | coelom. |
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37.
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In the tapeworm, both male and female reproductive organs are contained in each
mature
a. | proglottid. | c. | egg. | b. | cyst. | d. | scolex. |
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38.
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What conditions could be expected in an area where large numbers of
mud-dwelling, filter-feeding, marine annelids are found?
a. | abundance of roundworms | c. | low bacteria
population | b. | abundance of algae | d. | compacted muddy bottom |
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39.
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Most free-living flatworms are
a. | parasites. | c. | hermaphrodites. | b. | flukes. | d. | members of the class
Cestoda. |
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40.
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All roundworms
a. | are unsegmented. | c. | are parasites. | b. | cause human disease. | d. | reproduce
asexually. |
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