Enters the atmosphere through respiration and the burning of fossil fuels.
a. nitrogen
b. carbon dioxide
c. oxygen

What would happen to the nutrients in an ecosystem if decomposers, such as bacteria, didn’t exist there?

Compare and contrast region e in the illustration above with region d. describe the physical characteristics of each region.

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.