In organisms other than plants, when and where is the most atp produced? in thylakoids, during photosynthesis in nuclei, during cellular respiration in chloroplasts, during photosynthesis in mitochondria, during cellular respiration

During cellular respiration is the correct answer. 

ATP is the main fuel for the functioning of cells. It is produced in a process called oxidative metabolism, or respiration. The two forms of respiration are aerobic and anaerobic, or fermentation. The first one requires the presence of oxygen and the second one does not. What these processes have in common is that they are used to convert biochemical nutrients into usable energy. The end product of the two processes are molecules of adenosin triphosphate or ATP. At the and of the production cycle, the cell produces 2 molecules of ATP with the anaerobic respiration, and 38 molecules of ATP with the aerobic respiration.