1. Reptiles

2. Reptiles Do not regulate their own internal body temperature –
Must rely on the environment’s temperature to warm their bodies
Move in and out of the sun to regulate temperature (think snakes and alligators warming their bodies in the sunlight)
Because they are ectotherms, they are not found in cold environments
LAY EGGS WITH SHELLS!!!

3. Reptiles (continued) Have scaly skin–
Prevents loss of body moisture and provides additional protection from predators
Must rely on lungs for respiration
Legs placed more directly under the body compared to amphibians (which have legs at the sides of the body) –
Can support a greater body weight compared to amphibians (think crocodiles vs. salamanders)

4. Feeding in Reptiles
Herbivores and carnivores

5. Sense and Response in Reptiles
In some snakes, heat sensitive organs can detect prey
Snakes use their tongue to “taste air”

6. Circulation in Reptiles
Most reptiles have three-chambered hearts
Crocodiles have four-chambered hearts

7. Reproduction in Reptiles
Occurs on land – lay eggs – amniotic egg allowed reptiles to live on land – major evolutionary advancement
Amniotic egg – provides nourishment to the embryo and contains membranes that protect it during development
Internal fertilization – eggs laid after fertilization

8. The Amniotic Egg Amnion Embryo Allantois
The chorion regulates
the transport of
oxygen from the
surface of the egg
to the embryo and
carbon dioxide,
one product of
respiration, in the
opposite direction.
This baglike structure
contains a yolk that
serves as a nutrient-rich
food supply for the embryo.
The amnion is a fluid-filled sac
that surrounds and cushions
the developing embryo. It
produces a protected, watery
environment.
The allantois stores the
waste produced by the
embryo. It also serves
as a respiratory organ.
Chorion
Yolk sac
Shell

9. Groups of Reptiles 4 major groups of reptiles: Turtles and tortoises
Crocodilians
Snakes and lizards
Tuatara

10. Turtles and Tortoises
Shells (upper part called carapace) are part of the skeleton/backbone
Some aquatic others terrestrial (better known as tortoises

11. Crocodilians Major predators
Crocodiles vs. alligators – crocodiles have narrower snouts
Seen basking in sun with mouths open

12. Snakes and Lizards
Found in many different environments – from trees to deserts

13. Tuatara
Most primitive group of reptiles

14. Birds

15. Birds Birds are endotherms –
Maintain constant internal body temperature
Feathers reduce heat loss
Holding wings away from body and panting releases excess heat
Must eat large amounts of food to sustain high levels of energy

16. Birds (continued) Only organisms with feathers –
Lightweight, modified scales that provide insulation and allows for flight
Preening (grooming) keeps feathers in good condition – birds also rub oil from glands over their feathers for waterproofing
Molting – shedding of old feathers for new feathers

17. Two Feather Types Contour – long, rigid and used for flight
Down – small, fluffy, soft and used for insulation

18. Movement in Birds
Powerful flight muscles attached to sternum (breastbone)

19. Feeding in Birds
Shape of bird’s beak gives clues to types of food eaten
Hummingbirds vs. pelicans vs. hawks

20. Respiration in Birds
Lungs with anterior and posterior air sacs – need these sacs to assist with need for great deal of oxygen for flight muscles

21. Circulation in Birds Four-chambered heart for efficiency
Need four chambers for flying

22. Reproduction in Birds Occurs on land – lay eggs – amniotic egg
Amniotic egg – provides nourishment to the embryo and contains membranes that protect it during development
Internal fertilization – eggs laid after fertilization

23. Diversity of Birds
Common uniformity, but can exhibit specific adaptations to environments (hawks vs. penguins)