Deck 34: Vertebrates

Question 1

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Terry takes the body of the snakelike organism and slices it open along its dorsal side. If it is a hagfish, what should Terry see?

A)a well-developed series of bony vertebrae surrounding the spinal cord
B)a well-developed series of cartilaginous vertebrae surrounding the spinal cord
C)a tube of cartilage (surrounding the notochord)with dorsal projections on both sides of the spinal cord
D)a notochord, located underneath the spinal cord

Answer 1

D

Question 2

A new species of aquatic chordate is discovered that closely resembles an ancient form. It has the following characteristics: external armor of bony plates, no paired lateral fins, and a suspension-feeding mode of nutrition. In addition to these, it will probably have which of the following characteristics?

A)legs
B)no jaws
C)an amniotic egg
D)endothermy

Answer 2

B

Question 3

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Having caught and handled a hagfish, what will Terry's shipmates most likely require Terry to do before returning to further fishing?

A)Spend some time below deck; only someone who'd spent too much time in the sun would remove hagfish denticles for later "analysis."
B)Clean the bucketsful of hagfish slime from the deck of the boat.
C)Dispose of the fishing tackle that had been poisoned by coming into contact with the hagfish.
D)Cut up the remaining hagfish and share pieces of this highly sought-after baitfish.

Answer 3

B

Question 4

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
The earliest known mineralized structures in vertebrates are associated with which function?

A)reproduction
B)feeding
C)locomotion
D)defense
E)respiration

Question 5

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Terry saved some of the tooth-like objects within the hagfish's round mouth to analyze their composition in his mentor's biochemistry research lab. Terry will find that they are composed of the same protein found in reptilian

A)scales.
B)teeth.
C)bones.
D)blood.
E)muscles.

Question 6

Which of the following statements about craniates is (are)correct?
1) Craniates are more highly cephalized than are non-craniates.
2) Craniates' genomic evolution includes duplication of clusters of genes that code for transcription factors.
3) The craniate clade is synonymous with the vertebrate clade.
4) Pharyngeal slits that can assist in gas exchange originated in craniates,
5) The two-chambered heart originated with the early craniates.

A)1 only
B)1 and 3
C)2, 4, and 5
D)1, 2, 4, and 5
E)1, 3, 4, and 5

Question 7

The origin of the craniates occurred at roughly the same time as the

A)origin of the Ediacaran fauna.
B)Cambrian explosion.
C)Permian extinctions.
D)first invertebrates invaded land.
E)origin of lancelets.

Question 8

Chordate pharyngeal slits appear to have functioned first as

A)the digestive system's opening.
B)suspension-feeding devices.
C)components of the jaw.
D)gill slits for respiration.
E)portions of the inner ear.

Question 9

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
The snakelike organism turned out to be a hagfish. Consequently, why should Terry throw the fish he caught overboard, rather than having it for dinner?

A)It has mucus on its skin.
B)If it had an ectoparasite, then it must also have endoparasites.
C)The bite of the hagfish introduces paralytic neurotoxins, which Terry wants to avoid.
D)It was already sick or dying; otherwise, the hagfish would probably not have attacked it.

Question 10

Which of the following statements would be least acceptable to most zoologists?

A)The extant cephalochordates (lancelets)are contemporaries, not ancestors, of vertebrates.
B)The first fossils resembling cephalochordates appeared in the fossil record around 550 million years ago.
C)Recent work in molecular systematics supports the hypothesis that cephalochordates are the most recent common ancestor of all vertebrates.
D)The extant cephalochordates are the immediate ancestors of the fishes.
E)Cephalochordates display the same method of swimming as do fishes.

Question 11

Which extant chordates are postulated to be most like the earliest chordates in appearance?

A)lancelets
B)adult tunicates
C)amphibians
D)reptiles
E)chondrichthyans

Question 12

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Which feature excludes it from possibly being a leech?

A)its elongate shape
B)its lack of scales
C)its lack of external segmentation
D)its round mouth
E)its anterior sucker

Question 13

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
The feeding mode of the extinct conodonts was

A)herbivory.
B)suspension feeding.
C)predation.
D)filter feeding.
E)absorptive feeding.

Question 14

Which of the following is a shared characteristic of all chordates?

A)scales
B)jaws
C)vertebrae
D)dorsal, hollow nerve cord
E)four-chambered heart

Question 15

What is one characteristic that separates chordates from all other animals?

A)True coelom
B)post-anal tail
C)blastopore, which becomes the anus
D)bilateral symmetry
E)segmentation

Question 16

What do craniates have that earlier chordates did not have?

A)brain
B)vertebrae
C)post-anal tail
D)partial or complete skull
E)bone

Question 17

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Lampreys differ from hagfishes in

A)lacking jaws.
B)having a cranium.
C)having pharyngeal clefts that develop into pharyngeal slits.
D)having a notochord throughout life.
E)having a notochord that is surrounded by a tube of cartilage.

Question 18

Which of these are characteristics of all chordates during at least a portion of their development?

A)a dorsal, hollow nerve cord
B)pharyngeal clefts
C)post-anal tail
D)A and B only
E)A, B, and C

Question 19

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
Terry detaches the snakelike organism from the fish and uses a knife to cut off its head. In doing so, its brain slides out onto the deck of the boat. Terry peers into the cut end of the head and notices that the brain had lain in a sort of pan-like structure that only partially surrounded the brain. What is the structure Terry is observing, and what is it made of?

A)skull, bone
B)cranium, bone
C)cranium, cartilage
D)vertebral column, bone
E)vertebral column, cartilage

Question 20

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
What do hagfishes and lampreys have in common with the extinct conodonts?

A)lungs
B)the jawless condition
C)bony vertebrae
D)their mode of feeding
E)swim bladders

Question 21

What should be True of fossils of the earliest tetrapods?

A)They should show evidence of internal fertilization.
B)They should show evidence of having produced shelled eggs.
C)They should indicate limited adaptation to life on land.
D)They should be transitional forms with the fossils of chondrichthyans that lived at the same time.
E)They should feature the earliest indications of the appearance of jaws.

Question 22

Which of these statements accurately describes a similarity between sharks and ray-finned fishes?

A)The skin is typically covered by flattened bony scales.
B)They are equally able to exchange gases with the environment while stationary.
C)They are highly maneuverable due to their flexibility.
D)They have a lateral line that is sensitive to changes in water pressure.
E)A swim bladder helps control buoyancy.

Question 23

Arrange these taxonomic terms from most inclusive (i.e., most general)to least inclusive (i.e., most specific). 1. lobe-fins
2) amphibians
3) gnathostomes
4) osteichthyans
5) tetrapods

A)4, 3, 1, 5, 2
B)4, 3, 2, 5, 1
C)4, 2, 3, 5, 1
D)3, 4, 1, 5, 2
E)3, 4, 5, 1, 2

Question 24

All of these might have been observed in the common ancestor of chondrichthyans and osteichthyans, except

A)a mineralized, bony skeleton.
B)scales.
C)lungs.
D)gills.
E)a swim bladder.

Question 25

A trend first observed in the evolution of the earliest tetrapods was

A)the appearance of jaws.
B)the appearance of bony vertebrae.
C)feet with digits.
D)the mineralization of the endoskeleton.
E)the ability to move in a fishlike manner.

Question 26

To which of these are the scales of chondrichthyans most closely related in a structural sense?

A)osteichthyan scales
B)reptilian scales
C)mammalian scales
D)bird scales
E)chondrichthyan teeth

Question 27

A team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching segmental muscles from the skeletal elements. The team wants to test the poison's effectiveness in streams feeding Lake Michigan, but one critic worries about potential effects on lancelets, which are similar to lampreys in many ways. Why is this concern misplaced?

A)A chemical poisonous to lampreys could not also be toxic to organisms as ancestral as lancelets.
B)Lamprey larvae and lancelets have very different feeding mechanisms.
C)Lancelets do not have segmental muscles.
D)Lancelets live only in saltwater environments.
E)Lancelets and lamprey larvae eat different kinds of food.

Question 28

In which of these extant classes did jaws occur earliest?

A)lampreys
B)chondrichthyans
C)ray-finned fishes
D)lungfishes
E)placoderms

Question 29

All of the following belong to the lobe-fin clade, except

A)chondrichthyans.
B)Australian lungfishes.
C)African lungfishes.
D)coelacanths.
E)tetrapods.

Question 30

The lamprey species whose larvae live in freshwater streams, but whose adults live most of their lives in seawater, are similar in this respect to certain species of

A)chondrichthyans.
B)actinopterygians.
C)lungfishes.
D)coelacanths.
E)hagfishes.

Question 31

The swim bladder of ray-finned fishes

A)was probably modified from simple lungs of freshwater fishes.
B)developed into lungs in saltwater fishes.
C)first appeared in sharks.
D)provides buoyancy, but at a high energy cost.
E)both C and D

Question 32

There is evidence that ray-finned fishes originally evolved

A)in response to a crisis that wiped out the chondrichthyans.
B)directly from lampreys and hagfish.
C)early in the Cambrian period.
D)directly from cephalochordates.
E)in freshwater environments.

Question 33

Which group's members had (have)both lungs and gills during their adult lives?

A)sharks, skates, and rays
B)lungfishes
C)lancelets
D)amphibians
E)ichthyosaurs and plesiosaurs

Question 34

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
The organism was found to have two lungs, but the left lung was much smaller than the right lung. Kelly added that the herpetology instructor had said that in most snakes, the same condition exists. If the size difference between the lungs in this organism is not a shared ancestral characteristic with its occurrence in snakes, then its existence in this organism is explained as a(n) 1. result of convergent evolution.
2) example of homologous structures.
3) similar adaptation to a shared lifestyle or body-plan.
4) result of having identical Hox genes.
5) homoplasy.

A)3 only
B)1 and 5
C)1, 3, and 5
D)2, 3, and 5
E)3, 4, and 5

Question 35

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which characteristic should permit the class to conclude that it is probably not a snake?

A)its length
B)the number of eyes
C)the size and condition of its eyes
D)its presence in a burrow
E)the absence of scales on its surface

Question 36

What is a distinctive feature of the chondrichthyans?

A)an amniotic egg
B)unpaired fins
C)an acute sense of vision that includes the ability to distinguish colors
D)a mostly cartilaginous endoskeleton
E)lack of jaws

Question 37

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
The class decided to humanely euthanize the organism and subsequently dissect it. Having decided that it was probably not a reptile, two of their original hypotheses regarding its identity remained. Which of the following, if observed, should help them arrive at a conclusive answer?

A)presence of a closed circulatory system
B)presence of moist, highly vascularized skin
C)presence of lungs
D)presence of a nerve chord
E)presence of a digestive system with two openings

Question 38

According to one hypothesis, the jaws of vertebrates were derived by the modification of

A)scales of the lower lip.
B)skeletal rods that had supported pharyngeal (gill)slits.
C)one or more gill slits.
D)one or more of the bones of the cranium.
E)one or more of the vertebrae.

Question 39

The following questions refer to the description below.
Terry catches a ray-finned fish from the ocean and notices that, attached to its flank, there is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker and two small eyes. Terry thinks it might be a marine leech, a hagfish, or a lamprey.
The endoskeletons of most vertebrates are composed of calcified

A)cartilage.
B)silica.
C)chitin.
D)dentin.
E)enamel.

Question 40

The ray-finned fishes are characterized by

A)a bony endoskeleton, operculum, and usually a swim bladder.
B)a cartilaginous endoskeleton.
C)an amniotic egg.
D)teeth that are replaced regularly.
E)a lateral line system and ears with three semicircular canals.

Question 41

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which pair of numbers most likely represents extant, nonbird reptiles?

A)1 and 2
B)3 and 4
C)5 and 7
D)6 and 8
E)7 and 9

Question 42

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
What permits reptiles to thrive in arid environments?

A)Their bright coloration reflects the intense UV radiation.
B)A large number of prey and a limited number of predators are available in the desert.
C)A cartilaginous endoskeleton provides needed flexibility for locomotion on sand.
D)Their scales contain the protein keratin, which helps prevent dehydration.
E)They have an acute sense of sight, especially in bright sunlight.

Question 43

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Why is the discovery of the fossil Archaeopteryx significant? It supports the

A)phylogenetic relatedness of birds and reptiles.
B)contention that birds are much older than we originally thought.
C)claim that some dinosaurs had feathers well before birds had evolved.
D)idea that the first birds were ratites.
E)hypothesis that the earliest birds were ectothermic.

Question 44

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
The mystery organism probably belongs to which order, in which class?

A)order Anura, class Amphibia
B)order Apoda, class Amphibia
C)order Urodela, class Ampihibia
D)order Squamates, class Reptilia
E)order Tuatara, class Reptilia

Question 45

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which era is known as the "age of reptiles"?

A)Cenozoic
B)Mesozoic
C)Paleozoic
D)Precambrian
E)Cambrian

Question 46

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Most dinosaurs and pterosaurs become extinct at the close of the __________ era.

A)Cretaceous
B)Permian
C)Devonian
D)Ordovician
E)Triassic

Question 47

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which of the following are the only extant animals that descended directly from dinosaurs?

A)lizards
B)crocodiles
C)snakes
D)birds
E)mammals

Question 48

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Examination of the fossils of Archaeopteryx reveals that, in common with extant birds, it had

A)a long tail containing vertebrae.
B)feathers.
C)teeth.
D)both A and B
E)A, B, and C

Question 49

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
From which of the following groups are snakes most likely descended?

A)dinosaurs
B)plesiosaurs
C)lizards
D)crocodiles
E)synapsids

Question 50

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which of these is not considered an amniote?

A)amphibians
B)nonbird reptiles
C)birds
D)egg-laying mammals
E)placental mammals

Question 51

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which one of these, if found, should clear up any remaining doubt as to the identity of the organism?

A)vestigial pelvic girdle
B)blood vessels carrying oxygenated blood from both the skin and the functional lung to the heart
C)closed circulatory system
D)ability to produce toxins from glands located on the skin, or that empty into the mouth
E)two-chambered heart

Question 52

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
The condition of the eyes in this organism is similar to that seen in placental and marsupial moles. It is also most similar in functional significance to the

A)posterior-directed opening of the female bandicoot's marsupium.
B)honeycombed bones of carinates.
C)diaphragm of mammals.
D)lateral line systems of chondrichthyans and actinopterygians.
E)parapodia of polychaetes.

Question 53

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
The adaptation of snakes to their body shape has resulted in one of their lungs having become vestigial. Another adaptation (to a fossorial lifestyle)is snakes' absence of limbs. If the "mystery organism" has also become adapted to a fossorial lifestyle, though its ancestors moved about on the surface, then which structures should one expect to find upon dissecting the organism?
1) reduced or absent pelvic and/or pectoral girdles
2) metanephridia
3) hydrostatic skeleton

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

Question 54

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which of the following structures are possessed only by birds?

A)enlarged pectoral muscles and heavy bones
B)a four-chambered heart
C)feathers and keeled sternum
D)a short tail and scales
E)a large brain and endothermy

Question 55

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Why is the amniotic egg considered an important evolutionary breakthrough?

A)It has a shell that increases gas exchange.
B)It allows incubation of eggs in a terrestrial environment.
C)It prolongs embryonic development.
D)It provides insulation to conserve heat.
E)It permits internal fertilization to be replaced by external fertilization.

Question 56

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
The organisms represented by 8 most likely are

A)birds.
B)mammals.
C)nonbird, terrestrial reptiles.
D)aquatic reptiles.
E)all mammals except humans.

Question 57

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which organisms are represented by 6?

A)birds
B)mammals
C)nonbird, terrestrial reptiles
D)aquatic reptiles
E)all mammals except humans

Question 58

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which of these characteristics added most to vertebrate success in relatively dry environments?

A)the amniotic egg
B)the ability to maintain a constant body temperature
C)two pairs of appendages
D)claws
E)a four-chambered heart

Question 59

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which pair of numbers represents extinct reptiles that had returned to an aquatic life?

A)1 and 2
B)3 and 4
C)5 and 7
D)6 and 8
E)7 and 9

Question 60

The following questions refer to the description below.
While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-m-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).
Which of the following is characteristic of most extant reptiles and most extant mammals?

A)ectothermy
B)diaphragm
C)shelled eggs
D)keratinized skin
E)conical teeth that are relatively uniform in size.

Question 61

For the following items, match the extant vertebrate groups with the descriptions.
Internal fertilization, amniotic egg, skin that resists drying, heavy bones

A)amphibians
B)nonbird reptiles
C)chondrichthyans
D)mammals
E)birds

Question 62

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
During chordate evolution, what is the sequence (from earliest to most recent)in which the following structures arose?
1) amniotic egg
2) paired fins
3) jaws
4) swim bladder
5) four-chambered heart

A)2, 3, 4, 1, 5
B)3, 2, 4, 1, 5
C)3, 2, 1, 4, 5
D)2, 1, 4, 3, 5
E)2, 4, 3, 1, 5

Question 63

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which pair of numbers includes extant endotherms?

A)3 and 4
B)4 and 5
C)6 and 8
D)3 and 8
E)6 and 7

Question 64

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Whose forelimbs are most analogous to those of keeled birds and bats?

A)1
B)2
C)3
D)7
E)9

Question 65

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Whose DNA would have had the most sequence homologies with amphibian DNA?

A)5
B)6
C)7
D)8
E)9

Question 66

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which of these is a trend in hominin evolution?

A)increased ability to switch back and forth between bipedalism and quadrupedalism
B)well-developed claws for clinging to trees
C)a shoulder joint increasingly adapted to brachiation
D)increased brain to body ratio
E)a shortened period of parental care of offspring

Question 67

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which of these would a paleontologist be most likely to do in order to determine whether a fossil represents a reptile or a mammal?

A)Look for the presence of milk-producing glands.
B)Look for the mammalian characteristics of a four-chambered heart and a diaphragm.
C)Because mammals are eutherians, look for evidence of a placenta.
D)Use molecular analysis to look for the protein keratin.
E)Examine the teeth.

Question 68

For the following items, match the extant vertebrate groups with the descriptions.
No urinary bladder, females with one ovary, no teeth

A)amphibians
B)nonbird reptiles
C)chondrichthyans
D)mammals
E)birds

Question 69

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Differentiation of teeth is observed in

A)sharks.
B)bony fishes.
C)amphibians.
D)reptiles.
E)mammals.

Question 70

Which of these hominin traits seems to have occurred before the others?

A)tool use
B)increased brain size
C)symbolic thought
D)language
E)bipedalism

Question 71

Which are the most abundant and diverse of the extant vertebrates?

A)ray-finned fishes
B)birds
C)amphibians
D)nonbird reptiles
E)mammals

Question 72

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Which is characteristic of all mammals, and only of mammals?

A)a four-chambered heart that prevents mixing of oxygenated and deoxygenated blood
B)giving birth to live young (viviparous)
C)parental care of offspring
D)having glands to produce nourishing milk for offspring
E)using the rib cage to assist in ventilating the lungs

Question 73

For the following items, match the extant vertebrate groups with the descriptions.
Their scales closely resemble teeth in both structure and origin.

A)amphibians
B)nonbird reptiles
C)chondrichthyans
D)mammals
E)birds

Question 74

For the following items, match the extant vertebrate groups with the descriptions.
May have lungs, or gills, and may use skin as a respiratory surface

A)amphibians
B)nonbird reptiles
C)chondrichthyans
D)mammals
E)birds

Question 75

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
In which vertebrates is fertilization exclusively internal?

A)chondrichthyans, osteichthyans, and mammals
B)amphibians, mammals, and reptiles
C)chondrichthyans, osteichthyans, and reptiles
D)reptiles and mammals
E)reptiles and amphibians

Question 76

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
Among extant vertebrates, a sheet of muscle called the diaphragm is found in

A)birds.
B)mammals.
C)nonbird reptiles.
D)both A and B
E)A, B, and C

Question 77

The following questions refer to the phylogenetic tree shown in Figure 34.1.

Figure 34.1
How are primates different from all other mammals?

A)placental embryonic development
B)hairy bodies
C)arboreal lifestyles
D)ability to produce milk
E)opposable thumbs in many species

Question 78

For the following items, match the extant vertebrate groups with the descriptions.
Three major groups: egg-laying, pouched, and placental

A)amphibians
B)nonbird reptiles
C)chondrichthyans
D)mammals
E)birds

Question 79

Arrange the following taxonomic terms from most inclusive (i.e., most general)to least inclusive (i.e., most specific): 1. hominoids
2) hominins
3) Homo
4 anthropoids
5) primates

A)5, 1, 4, 2, 3
B)5, 4, 1, 2, 3
C)5, 4, 2, 1, 3
D)5, 2, 1, 4, 3
E)5, 2, 4, 1, 3

Question 80

What is the single unique characteristic that distinguishes extant birds from other extant vertebrates?

A)a hinged jaw
B)feathers
C)an amniotic egg
D)flight
E)a four-chambered heart