Which of the Following is Characteristic of Most Extant Reptiles

Question

Which of the following is characteristic of most extant reptiles and most extant mammals?
A) ectothermy
B) diaphragm
C) shelled eggs
D) keratinized skin
E) conical teeth that are relatively uniform in size

Accepted Answer

Most reptiles and mammals have keratinized skin, which helps to protect them from injury and water loss. This is a characteristic that sets them apart from other groups of animals, such as amphibians and fish.