Amphibians and Mammals

1. Amphibians and Mammals Objective 4.01 & 4.02: Analyze the classification of organisms & processes by which organisms accomplish essential life functions.

2. What does the word “Amphibian” mean? The word Amphibian means “dual life”. • Amphibians spend the first part of their life in the water and the second part of their life on land.

3. General Characteristics of Amphibians Amphibians have the following general characteristics: • Lay eggs in water (External fertilization and external development) • Ectotherms (Cold blooded) • Have 4 limbs • Skin is moist and covered with mucus.

4. Amphibian Cirulatory System • Closed circulatory system • 3 chambered heart

5. Amphibian Digestive System • Complete digestive system • Two openings : Mouth and anus • Food moves in one direction: Mouth  Anus

6. Amphibian Respiratory System • Gills as tadpoles • Lungs as adults • Skin must be moist for gas exchange (O2 and CO2)

7. Amphibian Nervous System • Have a brain, spinal cord and nerves

8. Amphibian Reproductive System • Sexual reproduction • External fertilization • Female lays eggs, male releases sperm • Undergo metamorphosis • Must occur in water

9. Amphibian Examples

10. Mammals

11. General Characteristics of Mammals • Body covered with hair or fur • Produce milk for young in mammary gland

12. Mammalian Circulatory System • Closed circulatory system • 4 chambered heart = no mixing of blood

13. Mammalian Digestive System • Complete digestive system • Two openings : Mouth and anus • Food moves in one direction: Mouth  Anus

14. Mammalian Respiratory System • Use lungs

15. Mammalian Nervous System • Have a brain, spinal cord and nerves

16. Mammalian Reproductive System • Internal fertilization • Three groups • Placental mammals – young develop in uterus • Monotremes – lay eggs • Marsupials – give birth to live young that further develops in pouch

17. Placentals, Monotremes and Marsupials