The only stage in aerobic respiration that requires oxygen is the last step, electron transfer phosphorylation. This step contains an electron transport chain similar to those that occur in photosynthesis. Electron transfer phosphorylation occurs primarily in the

answer; atp and nadph;

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: