Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis. While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.
The endosymbiotic theory hypothesizes that mitochondria and chloroplasts were formed when <u>prokaryotic </u>cells were engulfed by larger cells that were precursors to <u>eukaryotic </u>cells.
prokaryotic ; eukaryotic