Name ___________________________________ Date _________ Class _______

Section 33-1: Vertebrates Spread from the Sea to the Land

1. Vertebrates are Chordates with a ___________________

2. What does the backbone provide for vertebrates?
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3. List three characteristics that vertebrates share.
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4. List the six major organ systems that all vertebrates have. (See figure 33-2)
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5. The First Vertebrates were _____________ _____________

6. The first vertebrates appeared __________ million years ago.
7. The earliest fishes were called ___________________
8. The ___________ is an example of a modern day jawless fish (see fig 33-4)

6. Fishes Evolved Jaws and ____________________________

7. What were the two challenges to the survival of fish as predators?
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8. Jaws are though to have developed from ______________________________
9. Sharks and bony fishes appeared ________ million years ago.
10. Suggest a reason why sharks and bony fish replaced the early fish.
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11. How does a swim bladder help bony fishes? ____________________________

12. Today, ______________ Are the Largest Group of Vertebrates

13. What are the three groups that today's fishes belong to?
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14. Give 3 examples of bony fishes:
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15. The First Vertebrates to Venture onto Land Were ______________

16. Why do scientists think that amphibians evolved from lobe-finned fish?
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17. The "Age of Amphibians" was the ________________ period.

18. What three innovations were necessary for a species to live successfully on land?
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19. Why fact about amphibians suggests they are not fully adapted to land?
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20. Today, There are _________ Groups of Amphibians. What are they?
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