Free Response

Describe the functions of the three extra-embryonic membranes present in amniotic eggs.


The chorion facilitates the exchange of oxygen and carbon dioxide gases between the embryo and the surrounding air. The amnion protects the embryo from mechanical shock and prevents dehydration. The allantois stores nitrogenous wastes produced by the embryo and facilitates respiration.

What characteristics differentiate lizards and snakes?


Lizards differ from snakes by having eyelids, external ears, and less kinematic skulls.

Based on how reptiles thermoregulate, which climates would you predict to have the highest reptile population density, and why?


Reptiles are ectotherms, dependent on external sources to regulate their body temperature (i.e. their environment). The highest density of reptiles will therefore be in regions of the world with moderate temperatures, rather than areas that experience temperature extremes.