<span>In the sentence "Biologists recognize the following levels of cell organization: _____, the choice that correctly completes the sentence is b. cellular, tissue, organ, system, and organism. A cell is the basic unit of living organisms. The group of similar cells that work together to perform a specific job is a tissue. The group of multiple tissues joined together in the functional structure is an organ. Functionally related organs form organ systems, which all together form one organism.</span>
Light energy absorbed by chlorophyll is converted into chemical energy. Some of this energy is used to split water into hydrogen and oxygen. Some of the chemical energy is used to make ATP from ADP and phosphate (Pi). This chemical energy is stored as ATP.
