In the drawing of an egg longitudinal section below, label the following structures. Give two advantages of an external skeleton as seen in the insects, arachnids and crustaceans. Reptiles are the first group of animals to be completely liberated from a need to return to water for some portion of their life cycle. List two features that were significant evolutionary advancements of the class Reptilia over the Amphibia. They are the only egg-laying mammals.
Gestation is short and the young complete development outside the uterus in a special pouch.
They are only found in Australia 52. Islands are geologically very young. Islands are all ecologically similar. Scientists are always trying to find a cushy place to work. Describe the following reproductive isolation mechanisms 55.