Zoology Answers

How can you estimate the concentration of the urine that a species of rodent produces if the only information you are given is a photograph of an intact kidney from that species? Explain.

Most mammals have a layer of cutaneous fat beneath the skin, but dromedary camels concentrate fat storage in their hump. What is the significance of that difference for the thermoregulation of camels?

Compare the advantages and disadvantages of large body size for mammals that live in cold environments. Go beyond the information presented in the chapter.

What arctic animals use countercurrent circulation? Where in those animals is it most conspicuous?

Why does an endotherm’s metabolic rate increase above the upper lethal temperature? And why does the metabolic rate fall below the lower lethal temperature?

Four species of salamanders in the genus Desmognathus form a streamside salamander guild in the mountains of North Carolina. The four species are found at different distances from the stream, as listed in the table. Suggest one or more hypotheses to explain the relationship between the body sizes of these species and the distance each is found from water. What prediction can you make for each hypothesis, and how could you test that prediction?

What is the main new piece of information about early tetrapods that contradicts the old “drying pond” hypothesis of the origins of terrestriality?

What features of the elpistostegalian fishes lead us to infer that they were shallow-water forms?

What information about the Devonian tetrapods leads to the conclusion that tetrapods evolved in the water rather than on land?