CK12 Life Science

Lesson Summary

• Amphibians have adaptations for both aquatic, including gills, and terrestrial, includ-
  ing lungs and moist skin, lifestyles.


• Most amphibians are bound to water for reproduction.


• Development includes a shell-less egg, larval stage and adult.


• Salamanders have some unique features, including the use of the hyoid bone in hunting
  prey, and the process of ecdysis.


• Adult frogs and toads have features for living in the water (such as webbed digits) and
  for living on the land (such as long hind legs for jumping).


• Frogs are well known for their mating calls, which are used to attract females to aquatic
  breeding grounds.


• Amphibians play a role economically as a food source; are used in various types of
  biological research, can serve as indicators of ecosystem health, and figure prominently
  in folklore and popular culture.

Review Questions

1. Describe the general traits of amphibians.


2. Describe the life cycle of amphibians.


3. What are some adaptations of amphibians for living in a terrestrial environment?


4. A frog’s skin must remain moist at all times in order for oxygen to pass through the
   skin and into the blood. Why does this fact make frogs susceptible to many toxins in
   the environment?


5. The permeability of a frog’s skin can result in water loss. What adaptations would
   benefit a frog by counteracting this water loss?


6. Name how one feature of frog development lends itself to research applications.


7. Amphibians have a number of adaptations which make it easy for them to avoid pre-
   dation. Describe some of these.

Further Reading / Supplemental Links

• Unabridged Dictionary, Second Edition. Random House, New York, 1998.


• http://en.wikipedia.org/wiki


• http://kids.nationalgeographic.com/Animals


• http://amphibiaweb.org


• http://helpafrog.org


• http://www.amphibianark.org/yearofthefrog.htm


• http://www.epa.gov/gmpo/education/photo/amphibians.html