DENDROLOGY

Detailed explanation-1: -During photosynthesis, plants trap light energy with their leaves. Plants use the energy of the sun to change water and carbon dioxide into a sugar called glucose. Glucose is used by plants for energy and to make other substances like cellulose and starch.

Detailed explanation-2: -The Sun! The energy from light causes a chemical reaction that breaks down the molecules of carbon dioxide and water and reorganizes them to make the sugar (glucose) and oxygen gas.

Detailed explanation-3: -So it is clear that the energy for photosynthesis comes from light. The process of photosynthesis converts light energy into chemical energy that can be used for biological processes.