Living on land means reptiles can't rely on absorbing oxygen through their skin like amphibians. All reptiles have lungs they use for breathing -- even those who live most of their lives near or in water, such as crocodiles, must surface to breathe. Lungs allow reptiles to venture far away from aquatic environments.
Sample Response: Reptiles have dry, tough skin covered in scales, which reduces water loss. Reptiles breathe using lungs; they do not exchange gases through their skin. Their kidneys also help prevent water loss by concentrating their urine. Young reptiles develop inside an amniotic egg, which is covered with membranes and a shell to prevent it from drying out.
<span>In a population of field mice, favorable traits in the mice are likely to INCREASE over time, and unfavorable traits are likely to DECREASE over time.
