Front | Back |
Only _____ have a notochord, a tubular dorsal nerve cord, a pharynx with slits in the walls, and a tail extending past the anus.
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A. echinoderms
b. tunicates and lancelets c. vertebrates d. both b and c e. all of the above |
The only chordate feature still present in the human adult is
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Nerve cord
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Which of the following classes is represented only by fossil forms?
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Placodermi
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Gill slits function in _____ .
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A. respiration
b. circulation c. food trapping d. water regulation e. both a and c |
A shift from reliance on _____ to reliance on _____ was pivotal in the evolution of all vertebrates.
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A. the notochord; a backbone
b. filter feeding; jaws c. gills; lungs d. all of the above |
The first vertebrates included ____ .
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A. bony fishes
b. jawless fishes c. lobe-finned fishes d. both a and b |
The vertebrate jaw first appeared in which organism?
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Fishes
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Sharks, rays, and skates belong to what group?
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Cartilaginous fish
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Of all existing vertebrates, _____ are the most diverse.
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Bony fishes
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Amphibians are completely dependent on an aquatic environment for
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Reproduction
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A water environment provides more of all but which one of the following than does air?
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A. support
b. buoyancy c. constancy of temperature d. oxygen e. resistance to movement |
Generally the only amphibian groups that entirely escaped dependency on free-standing water are ____ .
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A. salamanders
b. toads c. caecilians d. all require it |
Reptiles moved fully onto land owing to _____ .
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A. tough skin
b. internal fertilization c. good kidneys d. amniote eggs e. all of the above |
A four-chambered heart evolved first in _____ .
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Crocodilians
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The first group to exhibit an amniotic egg belonged to the
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Reptilia
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