Answer: It is the process of manufacture of organic compounds from CO2 and H2O in the presence of sunlight as a source of energy. The first step of photosynthesis is light reaction which occurs in the grana of chloroplast. The major process in this step are (1) Photolysis of water and evolution of O2 (2) Photophosphorylation. It is the process of ATP formation from ADP using light energy. The second step is dark reaction; It occurs in stroma of chroloplast. Here CO2 is reduced to carbohydrates; using AT