Dear student, Photosynthesis is the process by which green plants synthesise their own food using carbon dioxide and water in the presence of sunlight and chlorophyll. Importance of photosynthesis: 1.All heterotrophs depend on plants to fulfil their energy requirements. 2.The amount of carbon dioxide in atmosphere is maintained at a constant level. 3.The byproduct of photosynthesis, oxygen is the main factor responsible for the maintenance of life on the Earth. Thanks and regards