Biology

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Across
  1. 2. Birds that have powder down that repels water
  2. 4. Vertebrae that has dry skin, lungs, and eggs with several membranes
  3. 6. Structure to help birds digest food
  4. 10. Dorsal part of the shell
  5. 12. Only surviving member of the order Sphenodonta
  6. 14. Made of protein and develop from pits in birds’ skin
  7. 16. How Crocodiles do gas exchange
  8. 17. Animals that generate their own body heat
  9. 18. Excrete nitrogenous wastes in this form...
Down
  1. 1. Type of circulatory system reptiles have
  2. 3. Fierce carnivores that are part of the order Crocodilia
  3. 5. Muscular organ that helps breakdown food
  4. 7. rely on behavior to help control body temperature
  5. 8. Period 245 mya when reptiles roamed earth
  6. 9. ventral part of the shell
  7. 11. Where urine is produced
  8. 13. Egg named after the amnion, one of the four membranes
  9. 15. When a bird exhales air fills the...