In amphibians, the is the most important organ for gass exchange.

Describe the response the kidneys have to dehydration and excessive water intake. what happens to the concentration of urine in each case ?

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.

Which of these substances does not protect against invaders in the nonspecific immune response? a. saliva b. mucus c. tears d. urine