Reptiles

Ms. Bridgeland

Introduction to Reptiles

What are Reptiles?

• Ectotherms: What is an ectotherm again?

Reptiles

• Ectotherm: an animal whose body does not produce much internal heat• “Cold-blooded”• An animal whose body

temperature can change based on its surrounding environment

Are reptiles vertebrates or invertebrates?

• Reptiles are Vertebrates that have lungs and scaly skin for their entire lives.

How do reptiles get their air?

• Reptiles get their oxygen from air and breathe entirely with lungs

Reptile Evolution

• Even through some reptiles that live in water like sea turtles can swim, they evolved from reptiles that lived on land. Therefore, even though they live in water, they still breathe with lungs, and come ashore to lay eggs.

Already, can you find some differences between Reptiles and Amphibians?

To thrive on land, what adaptations do reptiles need?

Adaptations

• Dry, tough skin that is covered in scales this protects reptiles from drying out because they often live far from water

• Kidneys (organs that filter waste) are special in that they filter waste in a way that reptiles do not lose too much water

• Lay eggs with shells (amniotic egg): protects embryo from drying out on land and from physical harm

Why does having tough skin with scales help animals live on land?

Scaly Skin Benefits

• Protects the reptiles from physical harm

• Helps conserve water, or keep it inside their bodies to help with living in the sun

An Egg with a Shell

• Reptiles lay their eggs on land

• Reptile eggs have a leathery shell and membranes that protect the developing embryo (baby reptile).

• Why do reptile eggs have these shells?

Why do reptiles lay eggs with shells?

• The shells keep the inside of the egg moist and keeps the egg from drying out

• This type of egg is called an amniotic egg.

• Tiny pores in the shell allow oxygen gas and carbon dioxide gas out

In addition to a shell, an amniotic egg has 3 important membranes:

• Yolk Sac: holds the yolk, which is the embryo’s energy supply

• Allantois: the embryo’s wastes collect inside

• Amnion: Protects the the embryo, cushioning it and keeping it moist

Amniotic Egg

Note: For the AMNIOTIC EGG, you will only be responsible for knowing what the Yolk sac, Allantois, and Amnion are and their

functions.