Chapter 32: Protostome Animals

25. Which of the following is the most inclusive group that would include a segmented marine animal that develops through spiral cleavage and has parapodia? a. Nematodes b. Annelids c. Brachiopods d. Mollusks e. Flatworms

b. Annelids

46. Which of the following groups contains the largest number of species? a. Rotifers b. Arthropods c. Annelids d. Phoronids e. Polychaetes

b. Arthropods

42. Members of which of the following groups have a pseudocoel? a. Arrow worms and horsehair worms b. Horsehair worms and nematodes c. Horsehair worms, nematodes, and arrow worms d. Nematoda, chelicerates, and arrow worms e. Horsehair worms, nematodes, and hexapods

b. Horsehair worms and nematodes

35. Some cephalopods have modified their excurrent siphon and mantle to allow them to a. ingest large prey. b. alter their buoyancy. c. move rapidly through the water. d. attach to a substrate. e. become parasitic.

c. move rapidly through the water.

44. Trichinella spiralis, the causative agent of the disease trichinosis, is a a. ribbon worm. b. flatworm. c. nematode. d. rotifer. e. annelid.

c. nematode.

61. The wingless insects belong to which of the following groups? a. Apterygotes b. Pterygotes c. Myriapods d. Arachnids e. Chelicerates

a. Apterygotes

56. Which of the following groups of crustaceans bears a superficial resemblance to mollusks? a. Barnacles b. Copepods c. Isopods d. Decapods e. Water fleas

a. Barnacles

54. Which of the following are so numerous that they are thought to be the most abundant of all marine arthropods? a. Crustaceans b. Millipedes c. Nematomorphs d. Barnacles e. Apterygotes

a. Crustaceans

1. Which of the following is not one of the traits that unite the protostomes? a. Dorsal nervous system b. Anterior brain c. Bilaterally symmetrical body plan d. Development of a mouth from a blastopore (in many species) e. All of the above

a. Dorsal nervous system

32. Which of the following statements concerning the mantle of mollusks is false? a. It is present in all groups of mollusks except the octopuses. b. In terrestrial gastropods, it is modified into a lung. c. It is part of a filtering device used for feeding in bivalves. d. It is used as the basis of jet propulsion by cephalopods. e. It secretes the shell that provides external protection in most molluscan groups.

a. It is present in all groups of mollusks except the octopuses.

62. Butterflies belong to which order of winged insects? a. Lepidoptera b. Coleoptera c. Diptera d. Trichoptera e. Isoptera

a. Lepidoptera

52. _______ can survive for at least 10 years in a dormant, dehydrated state. a. Myriapods b. Onychophorans c. Pycnogonids d. Tardigrades e. Trilobites

a. Myriapods

67. Wings evolved _______ in protostomes. a. once b. twice c. three times d. four times e. many times, independently

a. once

68. The diversification of insects about 450 million years ago corresponds with a. the appearance of the first land plants. b. the evolution of cartilaginous fish. c. the extinction of dinosaurs. d. changes in the CO2 concentration of the atmosphere. e. None of the above

a. the appearance of the first land plants.

8. Animals with thin cuticles are generally restricted to moist habitats because a. the thin cuticle causes water to be lost across the body surface. b. there are fewer predators in these habitats. c. these animals rely on flowing water to bring them food. d. All of the above e. None of the above

a. the thin cuticle causes water to be lost across the body surface.

64. Insects are different from other hexapods in that they possess a. a pair of antennae. b. a motion-sensitive receptor called Johnston's organ. c. a dorsal nerve cord. d. six pairs of appendages. e. an exoskeleton.

b. a motion-sensitive receptor called Johnston's organ.

15. Flatworms differ from cnidarians in that flatworms a. are radially symmetrical, whereas cnidarians are bilaterally symmetrical. b. have more complex internal organs than cnidarians do. c. are diploblastic, whereas cnidarians are triploblastic. d. have two openings to the digestive cavity, whereas cnidarians have only one. e. have an excretory system, whereas cnidarians do not.

b. have more complex internal organs than cnidarians do.

6. Spiral cleavage is found in a subset of lophotrchozoans, including the ribbon worms, annelids, and a. phoronids. b. mollusks. c. bryozoans. d. rotifers. e. flatworms.

b. mollusks.

28. The large and remarkable pogonophoran annelids live near deep-ocean hydrothermal (volcanic) vents where food items are scarce. Many species are able to obtain enough nutrition because a. they are able to conduct photosynthesis. b. their tissues harbor endosymbiotic bacteria that fix carbon by oxidizing hydrogen sulfide and methane. c. they fix carbon from the minerals found in the ocean's muddy floor. d. they filter algae out of ocean water. e. they feed on dead fish that sink to the ocean floor.

b. their tissues harbor endosymbiotic bacteria that fix carbon by oxidizing hydrogen sulfide and methane.

24. Which of the following groups includes animals with segmented coeloms? a. Bryozoans b. Mollusks c. Annelids d. Flatworms e. Nematodes

c. Annelids

18. Which of the following taxa includes more than 10,000 species? a. Bryozoans b. Loriciferans c. Flatworms d. Rotifers e. Monoplacophorans

c. Flatworms

65. Which of the following is not one of the major recognized groups of winged insects? a. Insects that cannot fold their wings back against the body b. Insects that can fold their wings and undergo incomplete metamorphosis c. Insects that do not undergo metamorphosis d. Insects that can fold their wings and undergo complete metamorphosis e. All of the above are major recognized groups.

c. Insects that do not undergo metamorphosis

40. Which of the following statements describes locomotion in nematodes? a. Rhythmically beating cilia move the animal forward. b. Circular and longitudinal muscles work against each other and the pseudocoelom to change the shape of the animal, moving it forward. c. Longitudinal muscles contract. d. A series of hairs that project backward engage the substrate; back-and-forth movements propel the animal forward. e. Water expelled through special ducts moves the animal forward.

c. Longitudinal muscles contract.

31. Which taxa have an open circulatory system, a complete digestive tract, and a reduction of the coelom? a. Rotifers b. Annelids c. Mollusks d. Nematodes e. Flatworms

c. Mollusks

4. Of the groups listed below, which is a descendant of the most recent common ancestor of lophotrochozoans? a. Sponges b. Vertebrates c. Mollusks d. Insects e. Cnidarians

c. Mollusks

48. The centipedes and millipedes belong to which group? a. Hexapods b. Arachnids c. Myriapods d. Annelids e. Chelicerates

c. Myriapods

41. Which of the following statements concerning nematodes is false? a. Parasitic nematodes infect many animal species, including humans and many domestic animals. b. Parasitic nematodes infect many crop plants. c. No nematode species is beneficial to humans. d. Free-living nematodes are often extremely abundant. e. The diet of nematodes is varied.

c. No nematode species is beneficial to humans.

9. The firm exoskeleton of insects has protective and supportive advantages, but it poses which of the following problems? a. The animal must consume large amounts of food to support the growth of the exoskeleton. b. The exoskeleton prevents the animal from moving rapidly. c. The exoskeleton cannot grow as the animal body inside it grows. d. The exoskeleton attracts predators. e. All of the above

c. The exoskeleton cannot grow as the animal body inside it grows.

13. Which of the following statements about the flatworms is false? a. Some are parasitic. b. They possess a mouth but no anus. c. They are diploblastic. d. They possess some degree of cephalization. e. Some possess complex life cycles.

c. They are diploblastic.

59. Which of the following statements concerning the tracheal system in insects is false? a. Tracheae are air sacs and tubular channels. b. Tracheae penetrate virtually every part of an insect's body. c. Tracheae extend through a single tube to an insect's mouth. d. Tracheae provide oxygen to the insects' tissues. e. Tracheae extend from external openings inward to tissues throughout the body.

c. Tracheae extend through a single tube to an insect's mouth.

39. An animal with bilateral symmetry, a pseudocoelom, a tubular digestive system, and a thick, multilayer cuticle is most likely a. an arrow worm. b. a flatworm. c. a nematode. d. a polychaete. e. an annelid.

c. a nematode.

45. An animal that has a hemocoel, a chitinous exo-skeleton, and a complete digestive tract would most likely be a. a nematode. b. an annelid. c. an arthropod. d. a mollusk. e. an arrow worm.

c. an arthropod.

33. Some mollusks have a rasping feeding structure known as the a. proboscis. b. rhynchocoel. c. radula. d. corona. e. mastax.

c. radula.

5. Many lineages of lophotrochozoans have a type of free-living larva known as a a. polyp. b. planula. c. trochophore. d. nauplius. e. None of the above

c. trochophore.

14. Flatworms are often parasitic. Which of the following is an adaptation found in flatworms that is associated with a parasitic lifestyle? a. Large size b. A highly branched gastrovascular cavity c. An oxygen transport system d. Absorption of nutrients through the body surface e. None of the above

d. Absorption of nutrients through the body surface

2. Which of the following animals have complete digestive tracts? a. Flukes b. Tapeworms c. Horsehair worms d. Annelids e. None of the above

d. Annelids

49. Organisms of which group are probably most similar to ancestral arthropods? a. Chelicerates b. Nematodes c. Crustaceans d. Onychophorans e. Trilobites

d. Onychophorans

36. Nautiluses are unique among living cephalopods in that they have a. an excurrent siphon. b. eyes comparable to vertebrates. c. an incurrent siphon. d. a chambered shell. e. All of the above

d. a chambered shell.

63. The most diverse (specious) group of insects consists of the a. grasshoppers and crickets. b. ants, bees, and wasps. c. lice. d. beetles. e. thrips.

d. beetles.

20. You discover a new organism with the following characteristics: the body is wormlike and has a fluid-filled cavity, the feeding organ looks like a proboscis, and there is a complete digestive tract. The organism is probably a(n) a. annelid. b. flatworm. c. nematode. d. ribbon worm. e. horsehair worm.

d. ribbon worm.

16. In free-living flatworms, which of the following functions occurs by simple diffusion? a. Respiration b. Absorption of nutrients c. Excretion d. Distribution of nutrients within the body e. All of the above

e. All of the above

47. Which of the following statements about exoskeletons is true? a. They are a highly efficient means of anchoring muscles, thereby providing more efficient movement. b. They provide protection from predators. c. They must be shed for the animal to grow, and during the shedding period the animal is vulnerable to predators. d. They provide support for walking on dry land. e. All of the above

e. All of the above

66. Which of the following statements about insect wings is false? a. The insect wing may have evolved from an ancestral appendage similar to that of modern crustaceans. b. Development of the insect wing is governed by the expression of the same gene that governs the crayfish appendage. c. Development of the insect wing and development of the crayfish appendage are controlled by the pdm gene. d. The pdm gene is expressed in both the wings and legs of insects. e. Appendages of ancestral crustaceans and wings of ancestral insects expressed the same gene (pdm).

e. Appendages of ancestral crustaceans and wings of ancestral insects expressed the same gene (pdm).

43. Which of the following groups does not have a circulatory system? a. Nematodes b. Chelicerates c. Crustaceans d. Horsehair worms e. Both a and d

e. Both a and d

7. Which of the following taxa does not contain wormlike organisms? a. Nematodes b. Clitellates c. Annelids d. Polychaetes e. Bryozoans

e. Bryozoans

60. Which one of the following arthropod groups includes the dragonflies? a. Myriapods b. Trilobites c. Chelicerates d. Crustaceans e. Hexapods

e. Hexapods

10. The evolution of a chitinous exoskeleton affected many aspects of arthropod evolution. The aspect that was least affected was the a. division of labor among the body parts. b. mode of locomotion. c. pattern of growth. d. system of gas exchange. e. mode of digestion.

e. mode of digestion.