(Q002) The Earth's atmosphere Group of answer choices began as nitrogen and oxygen, left over from the solar nebula. acquires its carbon dioxide from photosynthesis by green plants. gets warmer as its carbon dioxide concentration goes down. became more oxygen-rich during the Proterozoic, after the evolution of photosynthetic organisms in the Archean.

Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. the chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. the chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production c. free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone select the best answer from the choices provided

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

Environmental impacts on evolution : mastery test