21. Use your knowledge of temperature regulation to propose answers to the following questions:
--Why do some animals hibernate in winter?
--Why do dogs pant on hot days?
--What are 3 other methods that animals use to regulate internal temperature?

Identify characteristics of energy from the sun. check all that apply. almost all of the energy on earth comes from the sun. energy from the sun is known as mechanical energy. the energy in fossil fuels originally came from the sun. plants convert the energy of sunlight into chemical energy.

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.

Which two criteria must be met before scientist can use radiocarbon dating? explain your answer