1. Tuesday 4/12 Learning Goal:
Describe the characteristics and special adaptations of amphibians
Warm up:
What is an amphibian?
Homework:
Bring coloring supplies this week.
Bring disposable gloves for frog dissection on Monday!
Test on 11.3 & 11.4 on Monday 4/25

2. Chapter 11 Section 3
Amphibians

3. What is an amphibian? Examples: frog, salamanders, toads Vertebrate
Ectotherm
Early life spent in water
Most amphibians spend their adulthood on land
Return to water to reproduce

4. Two major groups Groups of Amphibians Salamanders: keep their tails
Frogs/Toads: lose their tails

5. Reproduction and Development
Amphibian: double life
Eggs are fertilized internally in most salamanders
Eggs are fertilized externally in most frog/toads
Fertilized eggs develop in water, larvae emerge from eggs, begin a free swimming, fishlike life
Tadpole: larva of a frog or toad
Salamander Metamorphosis
Larvae look like adults and lose gills
Less dramatic

6. Frog Metamorphosis

7. Living on Land
Respiratory and circulatory systems of adult amphibians are adapted for life on land
Adaptations for obtaining food and moving
Obtaining Oxygen
Amphibian larvae use gills to obtain oxygen in water
Lose gills during metamorphosis
Lungs
Organs of air-breathing vertebrates in which oxygen gas and carbon dioxide gas are exchanged
Oxygen also exchanged through skin

8. Circulatory system
Tadpole: Single loop and a heart with two chambers (like a fish)
Adult amphibians: two loops and a heart with three chambers
Atria: two upper chambers of a heart that receive blood
Oxygen rich and oxygen poor blood
Ventricle: blood moves into lower chamber pumps out to the lungs and body
Blood mixes here

9. Obtaining food Tadpoles: herbivores
Salamanders, frogs, toads: carnivores
Frog and toads wait for their prey to come close
Salamanders stalk and ambush their prey
Frogs and toads have camouflage skin helps obtain food and conceal from prey

10. Movement Adult amphibians have strong skeletons and muscular limbs
Frogs and toads have large legs for leaping and can absorb shock of landing

11. Amphibians in Danger Habitat: specific environment in which it lives
Destruction of habitats is causing populations of these animals to decrease
Amphibians are sensitive to changes in environment
Delicate skin
Eggs do not have shells