Which process made an increase in chemical energy for cell activities in organisms living on the earth possible?
a change from a primitive atmosphere, which was about 70 percent nitrogen, to
an atmosphere that was 70 percent oxygen
the development of plants that could add more water vapor to the atmosphere,
increasing the earth's water supply
the discovery of ATP and ADP by scientists for use in the metabolic processes of
cells
a change from a reducing atmosphere where there was no free oxygen to an
oxidizing environment where free oxygen was abundant