5) Sponges are most accurately described as
A) marine predators.
B) marine filter feeders.
C) freshwater scavengers.
D) aquatic filter feeders.
E) aquatic predators.

Answer: D

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

Answer: D

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).

Answer: D

8) The members of which clade in the phylum Cnidaria occur only as polyps?
A) Hydrozoa
B) Scyphozoa
C) Anthozoa
D) Cubozoa

Answer: C

9) Which clade in the phylum Cnidaria includes "jellies" with rounded (as opposed to boxlike) medusae?
A) Hydrozoa
B) Scyphozoa
C) Anthozoa
D) Cubozoa

Answer: B

10) Corals are most closely related to which group?
A) jellies
B) freshwater hydras
C) sea anemones
D) sponges
E) barnacles

Answer: C

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

Answer: D

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.

Answer: C

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

Answer: E

14) The excretory organs of annelids are
A) protonephridia.
B) flame bulbs.
C) metanephridia.
D) skin gills.
E) malpighian tubules.

Answer: C

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.

Answer: A

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

Answer: B

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.

Answer: B

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.

Answer: C

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.

Answer: C

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

Answer: A

21) Which mollusc clade includes members that undergo embryonic torsion?
A) chitons
B) bivalves
C) gastropods
D) cephalopods

Answer: C

22) A terrestrial mollusc without a shell belongs to which clade?
A) chitons
B) bivalves
C) gastropods
D) cephalopods

Answer: C

23) A radula is present in members of which clade(s)?
A) chitons
B) bivalves
C) gastropods
D) cephalopods
E) both chitons and gastropods

Answer: E

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

Answer: C

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.

Answer: B

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.

Answer: B

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

Answer: C

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

Answer: A

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

Answer: D

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

Answer: C

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

Answer: A

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

Answer: B

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

Answer: C

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.

Answer: D

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.

Answer: A

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.

Answer: A

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.

Answer: C

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.

Answer: D

39) The possession of two pairs of antennae is a characteristic of
A) spiders.
B) insects.
C) centipedes.
D) millipedes.
E) crustaceans.

Answer: E

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

Answer: D

41) Which of the following is a characteristic of adult echinoderms?
A) bilateral symmetry
B) spiral cleavage
C) gastrovascular cavity
D) exoskeleton
E) lophophore

Answer: A

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.

Answer: B

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

Answer: D

44) Which of the following animal groups is entirely aquatic?
A) Mollusca
B) Crustacea
C) Echinodermata
D) Nematoda
E) Platyhelminthes

Answer: C

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

Answer: A

46) Which of the following is a diploblastic phylum of aquatic predators?
A) Cnidaria
B) Annelida
C) Mollusca
D) Arthropoda
E) Echinodermata

Answer: A

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

Answer: E

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.

SEE IMAGE

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.

Answer: A

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.

SEE IMAGE

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.

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

Answer: D

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.

SEE IMAGE

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.

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

Answer: B

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.

SEE IMAGE

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.

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.

Answer: A

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

Answer: A

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

Answer: C

54) Aside from the density of dinoflagellates in P. ianthina skin, how many of the following factors can affect whether or not the endosymbiotic dinoflagellates promote the sea slug's survival (assuming latitudes above or below Earth's equator)?

1. day length
2. height of sun above the horizon
3. cloud cover
4. depth at which P. ianthina lives
5. water clarity

A) two of these
B) three of these
C) four of these
D) five of these

Answer: D

55) If the dinoflagellate-containing sea slug, P. ianthina, otherwise preys on coral animals, then it would be least surprising to find that
A) P. ianthina has no tolerance to the toxin in the nematocysts of its prey.
B) P. ianthina can locate its coral prey by chemicals released into the water by corals.
C) The coral prey harbor dinoflagellates in their tissues.
D) The coral prey transform themselves into medusas to flee from approaching P. ianthina.

Answer: C

56) The sea slug, Elysia chorotica, has no nematocysts or dinoflagellates but, rather, has "naked" chloroplasts in its skin. The chloroplasts are all that remain of the seaweed (Vaucheria sp.) that Elysia feeds upon. The chloroplasts are transferred to the skin; consequently, this slug is green. It spends most of its time basking in shallow water on the surface of seaweeds. How should we expect its chloroplasts to benefit the Elysia sea slug?

1. provide Elysia with fixed CO₂
2. provide Elysia with fixed N₂
3. provide Elysia with protective coloration

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 1, 2, and 3

Answer: D

The sea slug, Pteraeolidia ianthina, can harbor living dinoflagellates (photosynthetic protists) in its skin. These endosymbiotic dinoflagellates reproduce quickly enough to maintain their populations. Low populations do not affect the sea slugs very much, but high populations (> 5 x 105 cells/mg of sea slug protein) can promote sea slug survival.

57) If 100,000 sea slug cells together contain 1.0 mg of protein, then what is the minimum number of dinoflagellates per sea slug cell that constitutes a "high," and therefore beneficial, population?
A) 1 cell
B) 5 cells
C) 10 cells
D) 50 cells
E) 100 cells

Answer: B

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

58) The claws on the foremost trunk segment of centipedes have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

59) The feet of certain insects, notably of female butterflies, have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: A

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

60) The stingers of honeybees have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

61) The spiracles and tracheae of insects have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: B

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

62) The antennae of insects have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: A

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

63) The lateral flaps of planaria heads have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: A

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

64) The parapodia of polychaetes have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: B

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

65) The spines of sea stars have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

66) The small, thin extensions of the skin on the aboral surfaces of sea stars have a function most similar to that of
A) rhinophores.
B) dorsal plummules.
C) cerata.
D) more than one of these.

Answer: B

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

67) If nudibranch rhinophores are located at the anteriors of these sea slugs, then they contribute to the sea slugs'
A) segmentation.
B) lack of torsion.
C) cephalization.
D) identity as lophotrochozoans.
E) ability to successfully carry out a sessile lifestyle.

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

68) Nudibranchs usually have two rhinophores. However, if they had a single rhinophore, it could still carry out the function of two rhinophores, and with similar effectiveness, if this single rhinophore
A) had two branches, one directed to the left, the other to the right.
B) had two branches, one directed toward the head, the other directed toward the tail.
C) was as long as two rhinophores placed end to end.
D) had cilia whose power strokes directed water away from the surface of the slug.
E) was located within the mantle cavity.

Answer: A

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

69) The crown-of-thorns sea star, Acanthaster planci, preys on the flesh of live coral. At times, these sea stars undergo poorly understood population explosions. What impact should such explosions have on those sea slugs that bear cerata (cerata contain nematocysts)? Population explosions of this sea star should
A) benefit sea slugs by distracting their prey.
B) benefit sea slugs by helping subdue their prey.
C) harm sea slugs by competing with them for food.
D) harm sea slugs by consuming them as food.
E) harm sea slugs by fouling the water with their feces.

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

70) The sharp, inch-long thorns of the crown-of-thorns sea star are its spines. These spines, unlike those of most other sea stars, contain a potent toxin. If it were discovered that crown-of-thorns sea stars do not make this toxin themselves, then the most likely alternative would be that this toxin is
A) derived from the nematocysts of its prey.
B) absorbed from the surrounding seawater.
C) an endotoxin of cellulose-digesting bacteria that inhabit the sea star's digestive glands.
D) injected into individual thorns by mutualistic corals which live on the aboral surfaces of these sea stars.

Answer: A

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

71) The crown-of-thorns sea star, Acanthaster planci, preys on the flesh of live coral. If coral animals are attacked by these sea stars, then what actually provides nutrition to the sea star, and which chemical (besides the toxin within their nematocysts) do the corals rely on for protection?
A) medusas; silica
B) exoskeleton; silica
C) exoskeleton; calcium carbonate
D) polyps; calcium carbonate
E) polyps; silica

Answer: D

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

72) The reason their exoskeletons cannot protect the corals from sea stars is that the sea star
A) is immune to the toxin of the nematocysts.
B) thorns are sharp and toxic.
C) tubefeet act as tiny syringes that suck the corals out of their exoskeletons.
D) stomach can be everted, and can release digestive juices directly onto the corals.

Answer: D

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

73) A natural predator of the crown-of-thorns sea star is a mollusc called the Giant Triton, Charonia tritonis. If the triton uses a radula to saw into the sea star, then to which clade should the triton belong?
A) chitons
B) bivalves
C) gastropods
D) cephalopods

Answer: C

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips.

74) Which human profession is most analogous to the lifestyle of the sea slugs described in this scenario?
A) physician
B) pirate
C) pharmacist
D) plumber
E) painter

Answer: B

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles.

75) From this description, one can conclude that the organisms that have caught Sarah's attention are
A) insects.
B) crustaceans.
C) aquatic spiders.
D) myriapods.
E) eurypterids.

Answer: A

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles.

76) Sarah noticed the presence of many empty exoskeletons attached to emergent vegetation. These exoskeletons looked exactly like those of the largest of the "mystery organisms" she had seen in the pond. They also looked similar to the bodies of the dragonflies that patrolled the surface of the pond. If Sarah had learned a lot from her college biology class, what should she have concluded about the mysterious pond organisms?
A) They are larval dragonflies, destined to undergo incomplete metamorphosis.
B) They are larval dragonflies, destined to undergo complete metamorphosis.
C) They are adult dragonflies, so old that they can no longer fly, have fallen into the pond, but have not yet drowned.
D) They are adult dragonflies that must, like many amphibian species, return to water in order to mate.

Answer: A

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles.

77) If the pond organisms are larvae, rather than adults, Sarah should expect them to have all of the following structures, except
A) antennae.
B) an open circulatory system.
C) an exoskeleton of chitin.
D) complex eyes.
E) sex organs.

Answer: E

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles.

78) Sarah observed that the mystery pond organisms never come up to the pond's surface. If she catches one of these organisms and observes closely, perhaps dissecting the organism, she should find
A) gills.
B) spiracles.
C) tracheae.
D) book lungs.

Answer: A

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles.

79) Sarah had learned that ancestral (Carboniferous era) dragonfly species were much larger than extant dragonfly species are, with wingspans of 70 cm. This struck her as odd, because she had also learned that one of the things that keeps insects small is their relatively inefficient respiratory system. Which two hypotheses might help account for the large size of ancestral dragonflies?

1.If the atmosphere during the Carboniferous era had featured a higher oxygen content than the modern atmosphere, then the tracheae might have been a sufficient means for oxygen delivery to the interior tissues.
2. If large size was a drawback, then the large dragonflies underwent extinction, which explains why all extant dragonflies are smaller.
3. If the ancestral dragonflies had possessed muscles that permitted effective ventilation of the tracheae, then the tracheae might have been a sufficient means for oxygen delivery to the interior tissues.
4. If ancestral dragonflies existed during greenhouse conditions, then they must have survived by decreasing their activity levels, such as no longer capturing prey in flight. Thus, for them, an ineffective respiratory system was sufficient.

A) 1 and 2
B) 1 and 3
C) 1 and 4
D) 2 and 3
E) 2 and 4

Answer: B

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

80) One day, little Tommy (a student in an undersupervised class of 40 fifth graders) got the urge to pet Nemo (the clownfish), who was swimming among the waving petals of a pretty underwater "flower" that had a big hole in the midst of the petals. Tommy giggled upon finding that these petals felt sticky. A few hours later, Tommy was in the nurse's office with nausea and cramps. Microscopic examination of his fingers would probably have revealed the presence of
A) teeth marks.
B) spines.
C) spicules.
D) nematocysts.
E) a radula.

Answer: D

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

81) How many of the following organisms possess bilateral symmetry as adults?

1. sponges
2. molluscs
3. echinoderm
4. sea anemones
5. ectoprocts

A) one of these
B) two of these
C) three of these
D) four of these
E) five of these

Answer: D

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

82) If the teacher wanted to show the students what a lophophore is and how it works, the teacher would point out a feeding
A) hydra.
B) sponge.
C) bivalve.
D) gastropod.
E) ectoproct.

Answer: E

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

83) The bivalves started to die one by one; only the undamaged shells remained. To keep the remaining bivalves alive, the teacher would have to remove the
A) sea anemones.
B) sea star.
C) gastropods.
D) ectoprocts.
E) parrotfish.

Answer: B

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

84) If the teacher had used a dissecting microscope to examine the outer surfaces of the empty bivalve shells, the teacher would probably have seen marks that had been left by
A) jaws.
B) nematocysts.
C) tubefeet.
D) a lophophore.
E) a madreporite.

Answer: C

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

85) The teacher was unaware of the difference between suspension feeding and predation. The teacher thought that providing live copepods (2 mm long) and feeder fish (2 cm long) would satisfy the dietary needs of all of the organisms. Consequently, which two organisms would have been among the first to starve to death (assuming they lack photosynthetic endosymbionts)?
A) sponges and corals
B) sea stars and sponges
C) shrimp and bivalves
D) corals and bivalves
E) bivalves and sponges

Answer: E

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

86) If the teacher had wanted to demonstrate that some invertebrates possess a closed circulatory system, the teacher should have removed and dissected a
A) mollusc.
B) sea star.
C) shrimp.
D) polychaete.
E) parrotfish.

Answer: D

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates–a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish

87) Had the teacher wanted to point out organisms that belong to the most successful animal phylum, the teacher should have chosen the
A) bivalves and gastropods.
B) sea anemones and hydra.
C) shrimp and copepods.
D) polychaete.

Answer: C

88) The clownfish readily swims among the tentacles of the sea anemones; the parrotfish avoids them. One hypothesis for the clownfish's apparent immunity is that they slowly build a tolerance to the sea anemone's toxin. A second hypothesis is that a chemical in the mucus that coats the clownfish prevents the nematocysts from being triggered. Which of the following graphs supports the second, but not the first, of these hypotheses?

Answer: C

89) The teacher and class were especially saddened when the colonial hydrozoan died. They had watched it carefully, and the unfortunate creature never even got to produce offspring by budding. Yet, everyone was elated when Tommy (now recovered) noticed a small colonial hydrozoan growing in a part of the tank far from the location of the original colony. The teacher was apparently unaware that these hydrozoans exhibit
A) spontaneous generation.
B) abiogenesis.
C) alternation of generations.
D) ecdysis.
E) a medusa stage.

Answer: E

90) A land snail, a clam, and an octopus all share
A) a mantle.
B) a radula.
C) gills.
D) embryonic torsion.
E) distinct cephalization.

Answer: A

91) Which phylum is characterized by animals that have a segmented body?
A) Cnidaria
B) Platyhelminthes
C) Porifera
D) Arthropoda
E) Mollusca

Answer: D

92) The water vascular system of echinoderms
A) functions as a circulatory system that distributes nutrients to body cells.
B) functions in locomotion and feeding.
C) is bilateral in organization, even though the adult animal is not bilaterally symmetrical.
D) moves water through the animal's body during suspension feeding.
E) is analogous to the gastrovascular cavity of flatworms.

Answer: B

93) Which of the following combinations of phylum and description is incorrect?
A) Echinodermata–bilateral symmetry as a larva, coelom present
B) Nematoda–roundworms, pseudocoelomate
C) Cnidaria–radial symmetry, polyp and medusa body forms
D) Platyhelminthes–flatworms, gastrovascular cavity, acoelomate
E) Porifera–gastrovascular cavity, coelom present

Answer: E