1. Chordate Classes
The Amphibians
Pgs

2. Amphibian Body Characteristics
Body Symmetry: Bilateral
Cell Organization: Cells to tissues to organs to organ systems
Reproduction: Sexual
Body Development: “Double Life” Metamorphosize to adult

3. Frogs, Salamanders and Newts, and Toads
Three Orders of Amphibians
Frogs, Salamanders and Newts, and Toads

4. Caecilians – a rare legless amphibian
Just the facts…
Name means “double life”
Begin life in water, live on land, return to water to reproduce.
Are ECTOTHERMIC VERTEBRATES
Caecilians – a rare legless amphibian
Newt

5. Just the Facts… Skin lack scales, feathers, and hair
Must remain moist
Feet have no claws
3-chambered heart
The endangered Asian Giant salamander can grow up to 5 feet long!

6. Amphibian Metamorphosis – “Double Life”
Fertilization in frogs and toads is EXTERNAL
Fertilization is INTERNAL in most salamanders
Salamander Life Cycle

7. Frog Life Cycle Eggs are laid on or in water
Tadpoles live in fresh water and breathe with gills
Grows legs, loses its tail
Adapts to land by breathing with lungs
Life isn’t easy for a tadpole!

8. Life on Land How do amphibians breathe? How do amphibians get food?
How do amphibians move?

9. How do Amphibians Breathe?
Most amphibians lose their gills and develop lungs.
O2 and CO2 is also exchanged through their skin.
The Axolotl is the larva form of a salamander. It is at this stage that it breathes through gills; a mature adult breathes through lungs and its skin.

10. Moving Oxygen Through the Body
Three chambered heart
Path of Blood
Heart
Lungs
Body
Called a “double loop”
Happens in most vertebrates

11. How do Amphibians Eat? Tadpoles are HERBIVORES
Adult Amphibians are CARNIVORES
Insects, worms, slugs, etc.
Goliath frog eating another frog.

12. How do Amphibians Move? Salamanders crawl
Frogs and Toads have adaptations for jumping and swimming
Shock absorbing skeleton
Powerful hind legs
Webbed hind feet for swimming

13. Frog Facts!

14. Comparison of a Frog and a Toad

15. Frog Mouth

16. Frog Digestive System Mouth Esophagus Stomach Small Intestine
Large Intestine
Anus

17. Amphibian Systems - Circulatory
3 –chambered heart
2 lungs

18. Amphibian Systems - Nervous
Brain and Spinal Cord
Optic (eye) nerve

19. Why Study the Frog?
Many systems of the frog are similar to ours. So by studying the frog, we in turn, learn more about ourselves and the anatomy of the human species. Remember, biology is the study of life. The frog dissection is just one step of many steps that takes us closer to learning about the details of human life.