Sweating __________.

Dolphins have an insulating layer of blubber that protects them from cold water, but their flippers are not insulated. Propose a hypothesis to explain why dolphin flippers do not freeze. Describe an experiment you could do to test your hypothesis. (You may assume you have equipment for measuring temperatures in dolphin flippers.) What results would you expect if your hypothesis is correct?

In 1847, the German biologist Christian Bergmann noted that mammals and birds living at higher latitudes (farther from the equator) are on average larger and bulkier than related species living at lower latitudes. Suggest an evolutionary hypothesis to explain this observation.

Which of the following is a description of a behavior that helps warm the body?

During a fever, the __________ readjusts the set point of the body to a __________ temperature.

In the late fall, bats hibernate in clusters with many bats pressed together and holding on to one another. Which of the following statements does not represent an advantage of this behavior?

On a cold day, blood vessels in the skin __________.

By definition, an ectotherm __________.

The term endotherm refers specifically to __________.