Campbell’s Biology, 9e (Reece et al.)
Chapter 33 An Introduction to Invertebrates
Almost half of the questions in the Test Bank for this chapter are synthetic questions that comprise three
different scenarios, including a new scenario based on sea slugs. Fun!
Multiple-Choice Questions
1) A sponge’s structural materials (spicules, spongin) are manufactured by the
A) pore cells.
B) epidermal cells.
C) choanocytes.
D) amoebocytes.
2) How many of the following can be observed in the mesohyl of various undisturbed sponges at one
time or another?
1. amoebocytes
2. spicules
3. spongin
4. zygotes
5. choanocytes
A) one of these
B) two of these
C) three of these
D) four of these
E) five of these
3) Which chemical is synthesized by some sponges and acts as an antibiotic?
A) streptomycin
B) spongin
C) calcium carbonate
D) silica
E) cribrostatin
4) In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian?
A) amoebocyte
B) choanocyte
C) epidermal cell
D) pore cell
5) Sponges are most accurately described as
A) marine predators.
B) marine filter feeders.
C) freshwater scavengers.
D) aquatic filter feeders.
E) aquatic predators.
6) How many of the following are characteristics of at least some members of the phylum Cnidaria?
1. a gastrovascular cavity
2. a polyp stage
3. a medusa stage
4. cnidocytes
5. a pseudocoelom
A) one of these
B) two of these
C) three of these
D) four of these
E) five of these
7) Which of the following is true of members of the phylum Cnidaria?
A) They are not capable of locomotion because they lack true muscle tissue.
B) They are primarily filter feeders.
C) They have either, or both, of two body forms: mobile polyps and sessile medusae.
D) They may use a gastrovascular cavity as a hydrostatic skeleton.
E) They are the simplest organisms with a complete alimentary canal (two openings).
8) The members of which clade in the phylum Cnidaria occur only as polyps?
A) Hydrozoa
B) Scyphozoa
C) Anthozoa
D) Cubozoa
9) Which clade in the phylum Cnidaria includes “jellies” with rounded (as opposed to boxlike) medusae?
A) Hydrozoa
B) Scyphozoa
C) Anthozoa
D) Cubozoa
10) Corals are most closely related to which group?
A) jellies
B) freshwater hydras
C) sea anemones
D) sponges
E) barnacles
11) Which characteristic(s) is (are) shared by both cnidarians and flatworms?
A) dorsoventrally flattened bodies
B) true muscle
C) radial symmetry
D) a digestive system with a single opening
E) two of these
12) The organ(s) of respiratory gas exchange in oligochaetes is (are)
A) parapodia.
B) gills.
C) the skin.
D) book lungs.
E) pairs of hollow bristles.
13) Against which hard structure do the circular and longitudinal muscles of annelids work?
A) bristles
B) cuticle
C) shell
D) endoskeleton
E) hydrostatic skeleton
14) The excretory organs of annelids are
A) protonephridia.
B) flame bulbs.
C) metanephridia.
D) skin gills.
E) malpighian tubules.
15) Planarians lack dedicated respiratory and circulatory systems because
A) none of their cells are far removed from the gastrovascular cavity or from the external environment.
B) they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm.
C) their flame bulbs can carry out respiratory and circulatory functions.
D) their body cavity, a pseudocoelom, carries out these functions.
16) What would be the most effective method of reducing the incidence of blood flukes in a human
population?
A) reduce the mosquito population
B) reduce the freshwater snail population
C) purify all drinking water
D) avoid contact with rodent droppings
E) carefully wash all raw fruits and vegetables
17) The larvae of many common tapeworm species that infect humans are usually found
A) encysted in freshwater snails.
B) encysted in the muscles of an animal, such as a cow or pig.
C) crawling in the abdominal blood vessels of cows and pigs.
D) crawling in the intestines of cows and pigs.
18) While sampling marine plankton in a lab, a student encounters large numbers of fertilized eggs. The
student rears some of the eggs in the laboratory for further study and finds that the blastopore becomes
the mouth. The embryo develops into a trochophore larva and eventually has a true coelom. These eggs
probably belonged to a(n)
A) chordate.
B) echinoderm.
C) mollusc.
D) nematode.
E) arthropod.
19) A brachiopod can be distinguished from a bivalve by the presence of
A) two hinged shells.
B) a digestive system with separate mouth and anus.
C) a lophophore.
D) suspension feeding.
E) a distinct head.
20) If a lung were to be found in a mollusc, where would it be located?
A) mantle cavity
B) coelom
C) incurrent siphon
D) visceral mass
E) excurrent siphon
21) Which mollusc clade includes members that undergo embryonic torsion?
A) chitons
B) bivalves
C) gastropods
D) cephalopods
22) A terrestrial mollusc without a shell belongs to which clade?
A) chitons
B) bivalves
C) gastropods
D) cephalopods
23) A radula is present in members of which clade(s)?
A) chitons
B) bivalves
C) gastropods
D) cephalopods
E) both chitons and gastropods
24) Which of the following is found only among annelids?
A) a hydrostatic skeleton
B) segmentation
C) a clitellum
D) a closed circulatory system
E) a cuticle made of chitin
25) Which of the following is a characteristic of nematodes?
A) All species can be characterized as scavengers.
B) They have only longitudinal muscles.
C) They have a true coelom.
D) They have a gastrovascular cavity.
E) Many species are diploblastic.
26) Humans most frequently acquire trichinosis by
A) having sexual contact with an infected partner.
B) eating undercooked pork.
C) inhaling the eggs of worms.
D) eating undercooked beef.
E) being bitten by tsetse flies.
27) How many of the following can be used to distinguish a nematode worm from an annelid worm?
1. type of body cavity
2. number of muscle layers in the body wall
3. presence of segmentation
4. number of embryonic tissue layers
5. shape of worm in cross-sectional view
A) one of these
B) two of these
C) three of these
D) four of these
E) five of these
28) Nematode worms and annelid worms share which of the following features?
A) use of fluid in the body cavity as a hydrostatic skeleton
B) ecdysis
C) presence of a circulatory system
D) presence of segmentation
E) absence of species with parasitic lifestyles
29) A student observes a wormlike organism crawling about on dead organic matter. Later, the organism
sheds its outer covering. One possibility is that the organism is a larval insect (like a maggot). However,
it might be a member of the phylum ________, and one way to distinguish between the two possibilities
is by looking for ________.
A) Platyhelminthes; a cuticle of chitin
B) Nematoda; an alimentary canal
C) Annelida; a body cavity
D) Nematoda; a circulatory system
E) Annelida; muscle in the body wall
30) The heartworms that can accumulate within the hearts of dogs and other mammals have a
pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum
does the heartworm belong?
A) Platyhelminthes
B) Arthropoda
C) Nematoda
D) Acoela
E) Annelida
31) Infection with which parasite might cause excessive elasticity in human skeletal muscles?
A) trichinella worms
B) tapeworms
C) copepods
D) blood flukes
E) rotifers
32) Which of the following are entirely, or partly, composed of calcium carbonate?
A) spicules of siliceous sponges
B) coral animals’ exoskeletons
C) molluscs’ mantles
D) insects’ cuticles
E) nematodes’ cuticles
33) How many of the following are characteristics of arthropods?
1. protostome development
2. bilateral symmetry
3. a pseudocoelom
4. three embryonic germ layers
5. a closed circulatory system
A) one of these
B) two of these
C) three of these
D) four of these
E) five of these
34) Among the invertebrate phyla, phylum Arthropoda is unique in possessing members that have
A) a cuticle.
B) a ventral nerve cord.
C) open circulation.
D) wings.
E) segmented bodies.
35) A shared derived characteristic for members of the arthropod subgroup that includes spiders would
be the presence of
A) chelicerae.
B) an open circulatory system.
C) an exoskeleton.
D) a cuticle.
E) a cephalothorax.
36) You find a small animal with eight legs crawling up your bedroom wall. Closer examination will
probably reveal that this animal has
A) simple, but not compound, eyes.
B) two pairs of antennae.
C) a head, thorax, and abdomen.
D) tracheae and spiracles.
E) more than one of these.
37) What distinguishes complete metamorphosis from incomplete metamorphosis in insects?
A) the presence of wings in the adult, but not in earlier life stages
B) the presence of sex organs in the adult, but not in earlier life stages
C) the radically different appearance between adults and earlier life stages
D) Three of these responses are correct.
E) Two of these responses are correct.
38) A terrestrial animal species is discovered with the following larval characteristics: exoskeleton,
system of tubes for gas exchange, and modified segmentation. A knowledgeable zoologist should
predict that the adults of this species would also feature
A) eight legs.
B) two pairs of antennae.
C) a sessile lifestyle.
D) an open circulatory system.
E) parapodia.
39) The possession of two pairs of antennae is a characteristic of
A) spiders.
B) insects.
C) centipedes.
D) millipedes.
E) crustaceans.
40) One should expect to find the “9 + 2 pattern” of microtubules in association with the feeding
apparatus of which of the following?
A) annelids
B) coral animals
C) tapeworms
D) sponges
E) terrestrial insects
41) Which of the following is a characteristic of adult echinoderms?
A) bilateral symmetry
B) spiral cleavage
C) gastrovascular cavity
D) exoskeleton
E) lophophore
42) Which of the following describe(s) echinoderms?
A) They have an exoskeleton of hard calcareous plates.
B) Tubefeet provide motility in most species.
C) Digestion occurs completely outside of the organism.
D) Hemolymph circulates in the water vascular system.
E) They are found in both freshwater and saltwater environments.
43) A stalked, sessile marine organism has several feathery feeding structures surrounding an opening
through which food enters. The organism could potentially be a cnidarian, a lophophorate, a tube-
dwelling worm, a crustacean, or an echinoderm. Which of the following traits, if found in this organism,
would allow the greatest certainty of identification?
A) the presence of what seems to be radial symmetry
B) a hard covering made partly of calcium carbonate
C) a digestive system with mouth and anus separate from each other
D) a water vascular system
E) a nervous system
44) Which of the following animal groups is entirely aquatic?
A) Mollusca
B) Crustacea
C) Echinodermata
D) Nematoda
E) Platyhelminthes
45) In a tide pool, a student encounters an organism with a hard outer covering that contains much
calcium carbonate, an open circulatory system, and gills. The organism could potentially be a crab, a
shrimp, a barnacle, or a bivalve. The presence of which of the following structures would allow for the
most certain identification of the organism?
A) a mantle
B) a heart
C) a body cavity
D) a filter-feeding apparatus
E) eyes
46) Which of the following is a diploblastic phylum of aquatic predators?
A) Cnidaria
B) Annelida
C) Mollusca
D) Arthropoda
E) Echinodermata
Art Questions
47) Which of the following factors, when used to label the horizontal axis of the previous graph, would
account most directly for the shape of the plot?
A) spongin concentration (gm/unit volume)
B) rate of cribrostatin synthesis (molecules/unit time)
C) number of pores per sponge
D) number of spicules per sponge
E) number of choanocytes per sponge
13
This nudibranch, a type of sea slug, has many reddish cerata on its dorsal surface, as well as two, white-
tipped rhinophores located on the head.
The nontaxonomic term sea slug encompasses a wide variety of marine gastropods. One feature they
share as adults is the lack of a shell. We might think, therefore, that they represent defenseless morsels
for predators. In fact, sea slugs have multiple defenses. Some sea slugs prey on sponges and concentrate
sponge toxins in their tissues. Others feed on cnidarians, digesting everything except the nematocysts,
which they then transfer to their own skins. Whereas the most brightly colored sea slugs are often highly
toxic, others are nontoxic and mimic the coloration of the toxic species. Their colors are mostly derived
from pigments in their prey. There are also sea slugs that use their coloration to blend into their
environments.
48) Sea slugs can obtain nematocysts by preying on sea
A) anemones.
B) urchins.
C) daisies.
D) cucumbers.
E) lilies.
49) Which structure do sea slugs use to feed on their prey?
A) nematocysts
B) a sharp beak
C) an incurrent siphon
D) a radula
E) a mantle cavity
50) By which structures are nematocysts most likely to reach the skin of sea slugs?
A) the closed circulatory system
B) branches of the intestine
C) branches of the excurrent siphon
D) branches of the nephridium
E) branches of the pseudocoelom
51) The nematocysts of sea slugs should be most effective at protecting individual sea slugs from
predation if the predators
A) remove small bites of flesh from sea slugs, and have long-term memory.
B) remove small bites of flesh from sea slugs, and have no long-term memory.
C) consume entire sea slugs in one gulp, and have no long-term memory.
D) consume entire sea slugs in one gulp, and have long-term memory.
Percent of sea slug respiratory carbon demand provided by indwelling dinoflagellates.
52) According to the graph, during which season(s) of the year is the relationship between the sea slug
and its dinoflagellates closest to being commensal?
A) winter
B) spring
C) summer
D) fall
E) spring and fall
53) If we assume that carbon is the sole nutrient needed by sea slugs to drive their cellular respiration,
then based on the graph, during which season(s) is it least necessary for P. ianthina to act as a
chemoheterotroph?
A) winter
B) spring
C) summer
D) fall
E) spring and fall