DENDROLOGY

Detailed explanation-1: -Photosynthesis is the process of synthesis of food by plants using carbon dioxide and water in presence of sunlight and chlorophyll. Oxygen (O2) is released during the process as a waste product. Hence, oxygen is not essential for the process of photosynthesis.

Detailed explanation-2: -Oxygen is mainly released as a by-product by photolysis of water and released in the atmosphere. Thus, it is not required for photosynthesis.

Detailed explanation-3: -Carbon, hydrogen, and oxygen are the chemical ingredients necessary for photosynthesis to take place. Hydrogen and oxygen both come from the water in the hydrosphere. Carbon and oxygen come from the carbon dioxide that animals and humans breathe into the atmosphere.

Detailed explanation-4: -Plants are autotrophs, which means they produce their own food. They use the process of photosynthesis to transform water, sunlight, and carbon dioxide into oxygen, and simple sugars that the plant uses as fuel.

Detailed explanation-5: -The correct answer is ‘photosynthetic bacteria’.