Chapter 15 Section 3 Amphibians

Standard: The anatomy and physiology of animals illustrate the complementary nature of structure and function EQ: Explain how amphibians breathe

I. Amphibians and evolution- A) Amphibians were the first animals to move onto land. A) Amphibians were the first animals to move onto land. B) They evolved from ancient lungfish B) They evolved from ancient lungfish C) Fossils show that these first amphibians looked like a cross between a fish and a salamander C) Fossils show that these first amphibians looked like a cross between a fish and a salamander

II. Characteristics of Amphibians: A) Smooth, thin, moist skin- amphibians do not drink water but absorb it through their skin. They also breathe by gulping air or absorbing it through their skin A) Smooth, thin, moist skin- amphibians do not drink water but absorb it through their skin. They also breathe by gulping air or absorbing it through their skin

1- The skin of many amphibians contain poison glands –can be irritating or deadly 1- The skin of many amphibians contain poison glands –can be irritating or deadly 2- One frog produces a chemical that makes a snake yawn so if it tries to eat it, it yawns and the frog jumps out 2- One frog produces a chemical that makes a snake yawn so if it tries to eat it, it yawns and the frog jumps out 3- They are brightly colored as a warning to predators 3- They are brightly colored as a warning to predators

B) Many amphibians go through metamorphosis- Many frogs start off in the water as a tadpole then develop into a land dwelling frog. Some frogs and salamanders skip the aquatic stage Many frogs start off in the water as a tadpole then develop into a land dwelling frog. Some frogs and salamanders skip the aquatic stage

II. Kinds of amphibians: A) Caecilians- do not have legs, are shaped like worms, live in tropical areas of Asia, S. America, and Africa A) Caecilians- do not have legs, are shaped like worms, live in tropical areas of Asia, S. America, and Africa

B) Salamanders- have four legs, a long tail. B) Salamanders- have four legs, a long tail. 1- Salamanders live in damp forests of North America. They live under logs, rocks and most go through metamorphosis. 1- Salamanders live in damp forests of North America. They live under logs, rocks and most go through metamorphosis. 2- Some do not go through metamorphosis like the axolotl and live its entire life in water 2- Some do not go through metamorphosis like the axolotl and live its entire life in water

C) Frogs and Toads- 90% of amphibians are frogs and toads C) Frogs and Toads- 90% of amphibians are frogs and toads 1- found all over the world from deserts to rain forests 1- found all over the world from deserts to rain forests 2- Frogs have smooth skin 2- Frogs have smooth skin 3- Toads have drier skin and spend less time in water 3- Toads have drier skin and spend less time in water

Standard: The anatomy and physiology of animals illustrate the complementary nature of structure and function EQ: Explain how amphibians breathe