1. Which of the following statements regarding all species of chordates is false?
a. Chordates are deuterostomes.
b. A notochord is present in the embryo.
c. The notochord is surrounded by bone or cartilage.
d. All possess a postanal tail during embryonic development.
The correct answer is c—
A. Answer a is incorrect. This statement is true.
The correct answer is c—
B. Answer b is incorrect. This statement is true.
The correct answer is c—The notochord is surrounded by bone or cartilage.
C. Answer c is correct. The urochordates and cephalochordates lack vertebrae or
cartilage.
The correct answer is c—
D. Answer d is incorrect. This statement is true.
2. In the following figure, item A is the ______ and item B is the _____________.
a. complete digestive system; notochord
b. spinal cord; nerve cord
c. notochord; nerve cord
d. pharyngeal slits, notochord
The correct answer is c—
A. Answer a is incorrect. Refer to Figure 35.1.
The correct answer is c—
B. Answer b is incorrect. Refer to Figure 35.1.
The correct answer is c—notochord; nerve cord
C. Answer c is correct.
The correct answer is c—
D. Answer d is incorrect. Refer to Figure 35.1.
3. During embryonic development, a neural crest would be found in all of the
following chordates, except—
a. cephalochordates
b. reptiles
c. birds
d. mammals
The correct answer is a—cephalochordates
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A. Answer a is correct. Invertebrate chordates lack a neural crest.
The correct answer is a—
B. Answer b is incorrect. Neural crests are present in the vertebrate chordates.
The correct answer is a—
C. Answer c is incorrect. Neural crests are present in the vertebrate chordates.
The correct answer is a—
D. Answer d is incorrect. Neural crests are present in the vertebrate chordates.
4. A single-loop closed circulatory system is a characteristic of all ________.
a. amphibians
b. birds
c. reptiles
d. fish
The correct answer is d—
A. Answer a is incorrect. The amphibians possess both pulmonary and systemic
loops in their circulatory system.
The correct answer is d—
B. Answer b is incorrect. The birds possess both pulmonary and systemic loops in
their circulatory system.
The correct answer is d—
C. Answer c is incorrect. The reptiles possess both pulmonary and systemic loops in
their circulatory system.
The correct answer is d—fish
D. Answer d is correct. The fish lack a pulmonary loop in their circulatory system.
5. The ________ of the body fish evolves to counter the effects of increased bone
density.
a. gills
b. jaws
c. swim bladder
d. teeth
The correct answer is c—
A. Answer a is incorrect. Gills evolved in fish prior to the evolution of the bony fish.
The correct answer is c—
B. Answer b is incorrect. Jaws evolved in fish prior to the evolution of the bony fish.
The correct answer is c—swim bladder
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C. Answer c is correct. Swim bladders initially evolved for buoyancy.
The correct answer is c—
D. Answer d is incorrect. Teeth evolved in fish prior to the evolution of the body
fish.
6. From which group of fish did the amphibians originate?
a. Ray-finned
b. Lobe-finned
c. Cartilaginous
d. Acanthodians
The correct answer is b—
A. Answer a is incorrect. The ray-finned fish are not the direct ancestors of the
amphibians.
The correct answer is b—Lobe-finned
B. Answer b is correct.
The correct answer is b—
C. Answer c is incorrect. The cartilaginous fish are not the direct ancestors of the
amphibians.
The correct answer is b—
D. Answer d is incorrect. The acanthodians (spiny fish) are not the direct ancestors of
the amphibians.
7. Icthyostega represents __________.
a. the first chordate
b. a feathered reptile
c. the first amphibian
d. an early cartilaginous fish
The correct answer is c—
A. Answer a is incorrect.
The correct answer is c—
B. Answer b is incorrect.
The correct answer is c—the first amphibian
C. Answer c is correct.
The correct answer is c—
D. Answer d is incorrect.
8. Why was the evolution of the pulmonary veins important for amphibians?
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a.
b.
c.
d.
To move oxygen to and from the lungs
To increase the metabolic rate
For increased blood circulation to the brain
None of the above
The correct answer is a—To move oxygen to and from the lungs
A. Answer a is correct. These veins are part of the pulmonary circuit.
The correct answer is a—
B. Answer b is incorrect. Pulmonary refers to lungs.
The correct answer is a—
C. Answer c is incorrect. Pulmonary refers to lungs.
The correct answer is a—
D. Answer d is incorrect. Pulmonary refers to lungs.
9. The first group of animals to utilize an amniotic egg is the __________.
a. birds
b. mammals
c. amphibians
d. reptiles
The correct answer is d—
A. Answer a is incorrect. Although birds use an amniotic egg, they evolved from
reptiles.
The correct answer is d—
B. Answer b is incorrect. Although some mammals use an amniotic egg, they are
evolved from reptiles.
The correct answer is d—
C. Answer c is incorrect. Amphibians do not use amniotic eggs.
The correct answer is d—reptiles
D. Answer d is correct.
10. Which of the following groups lacks a four-chambered heart?
a. Birds
b. Reptiles
c. Mammals
d. Amphibians
The correct answer is d—
A. Answer a is incorrect. Birds possess a four-chambered heart.
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The correct answer is d—
B. Answer b is incorrect. Although not all reptiles have four-chambered hearts, the
characteristic first evolved in this group, and some reptiles have a four-chambered
heart.
The correct answer is d—
C. Answer c is incorrect. The mammals possess a four-chambered heart.
The correct answer is d—Amphibians
D. Answer d is correct. Amphibians possess three-chambered hearts.
11. All of the following are characteristics of reptiles, except—
a. cutaneous respiration
b. amniotic egg
c. thoracic breathing
d. dry, watertight skin
The correct answer is a—cutaneous respiration
A. Answer a is correct. Due to their dry skin, cutaneous respiration is almost
nonexistent in reptiles.
The correct answer is a—
B. Answer b is incorrect. This is characteristic of reptiles.
The correct answer is a—
C. Answer c is incorrect. This is a characteristic of reptiles.
The correct answer is a—
D. Answer d is incorrect. This is a characteristic of reptiles.
12. Which of the following evolutionary adaptations allows birds to become efficient
at flying?
a. Structure of the feather
b. High metabolic temperatures
c. Increased respiratory efficiency
d. All of the above
The correct answer is d—
A. Answer a is incorrect. Although this statement is correct, it is not the only one.
The correct answer is d—
B. Answer b is incorrect. Although this statement is correct, it is not the only one.
The correct answer is d—
C. Answer c is incorrect. Although this statement is correct, it is not the only one.
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The correct answer is d—All of the above
D. Answer d is correct.
13. The group of mammals that is most closely related to the reptiles is the ____.
a. therapsids
b. marsupials
c. monotremes
d. placentals
The correct answer is c—
A. Answer a is incorrect. The therapsids are reptiles, not mammals.
The correct answer is c—
B. Answer b is incorrect. This group does not share many characteristics with the
reptiles.
The correct answer is c—monotremes
C. Answer c is correct. This group does shares many characteristics with the reptiles.
The correct answer is c—
D. Answer d is incorrect. This group does not share many characteristics with the
reptiles.
14. Which of the following groups only includes the apes and humans and their direct
ancestors?
a. Hominoids
b. Primates
c. Arthropoids
d. Placentals
The correct answer is a—Hominoids
A. Answer a is correct.
The correct answer is a—
B. Answer b is incorrect. This group includes all mammals with grasping hands and
binocular vision.
The correct answer is a—
C. Answer c is incorrect. This group includes the monkeys, apes, and hominids.
The correct answer is a—
D. Answer d is incorrect. This group includes many nonprimate mammals.
15. Which of the following species was the first hominid to move from Africa in
social groups?
a. Homo habilis
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b. Homo erectus
c. Homo sapiens
d. Homo floresiensis
The correct answer is b—
A. Answer a is incorrect. There is no evidence of H. habilis leaving Africa.
The correct answer is b—Homo erectus
B. Answer b is correct.
The correct answer is b—
C. Answer c is incorrect. Other species of hominids left Africa before H. sapiens.
The correct answer is b—
D. Answer d is incorrect. There is no evidence of H. floresiensis leaving Africa.
Challenge Questions
1. Some scientists believe the feathers did not evolve initially for flight, but rather
for insulation. What benefits would this have had for early flightless birds?
Answer—Increased insulation would have allowed birds to become endothermic and
thus to be active at times that ectothermic species could not be active. High body
temperature may also allow flight muscles to function more efficiently.
2. Some people state that the dinosaurs have not “gone extinct,” they are with us
today. What evidence can be used to support this statement?
Answer—Birds evolved from one type of dinosaurs. Thus, in phylogenetic terms, birds
are a type of dinosaur.
3. Some people may state the humans are evolved from apes, yet this statement is
not truly correct. Why?
Answer—Humans and apes share a common evolutionary ancestor. Following the
divergence of these two groups 8–10 MYA, the apes diverged into the group we now
know as the apes, while the hominids diverged into the genus Homo. See Figure 35.37.
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