BIO 200LLB Lecture 22: Bio Lecture 22

• School: University at Buffalo
• Department: Biological Sciences
• Course: BIO 200LLB
• Professor: J. Poulin

Document Summary

Reptiles are the first group of amniotes: all have amniotic eggs. Amniotic eggs: eggs with a rich food source known as the yolk. Watertight shells and four internal membranes that allow for gas exchange and waste removal: these four membranes eliminate the need for water that is associated with gestation and embryonic development. Amniotes have internal fertilization: sperm must be placed inside the female where it will fertilize the egg before those membranes fully dorm. After fertilization and membrane formation, reptile and birds, have external gestation: mammals have internal gestation due to the lost shell of the egg. Layer of keratin rich scales that prevent water loss: keratin found in our fingernails, feathers, and scales are not homologous. Thoracic breathing: lungs have greater surface are. Lungs are inflated and deflated by the bellows like expansion and contraction of the rib cage. Sucks air through the lungs and pushes it back out through the mouth.