How do molecules within organisms become rearranged and used as energy sources?

When organisms convert from of energy, what usually results

Which of the following is the best definition of aerobic respiration? o a. the cellular process that releases energy by breaking down glucose o b. physical activity that involves the repeated motion of large muscle groups o c. physical activity that increases heart rate and breathing rate o d. the cellular process that converts solar energy to chemical energy

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important