Question

By which of the following processes ATP is produced?

I.	Photosynthesis
II.	Aerobic respiration
III.	Anaerobic respiration

• A. I only
• B. II only
• C. I and III only
• D. II and III only
• E. I, II, and III

Answer 1

The correct option is E I, II, and III

Photosynthesis is the fixation of atmospheric carbon dioxide into organic compounds; use of water as the electron donor by photoautotrophs during photophosphorylation results in the production of oxygen. Light reaction of photosynthesis includes trapping of Sunlight by chlorophyll a and other accessory pigments and production of ATP and NADPH. Aerobic respiration is the breakdown of sugar/other food substances in the presence of oxygen to released energy. It includes glycolysis, Krebs cycle and electron transport chain. Glycolysis and Kreb cycle produce reducing compounds NADH, FADH${}_2$ which are then oxidized in the presence of oxygen by the process of chemiosmosis to produce a large amount of ATPs. Anaerobic respiration/Fermentation is incomplete oxidation of food substances into alcohol and lactic acid with small amount of energy being released. This makes option E correct answer.