How is the light used in photosynthesis?
The light used in photosynthesis is absorbed by a green pigment called chlorophyll. Each food-making cell in a plant leaf contains chlorophyll in small bodies called chloroplasts. In chloroplast, light energy causes water drawn form the soil to split into hydrogen and oxygen. 
What are the steps of photosynthesis process?
Let me tell you the process of photosynthesis, in a series of complicated steps, the hydrogen combines with carbon dioxide from the air, forming a simple sugar. Oxygen from the water molecules is given off in the process. From sugar together with nitrogen, sulphur, and phosporus from the soil-green plants can make starch, fat, protein, vitamins, and other complex compounds essential for life. Photosynthesis provides the chemical energy that is needed to produced these compounds.
Sourches: http://bos-sulap.blogspot.com/2010/10/explanation-text-about-photosynthesis.html
Plants are living things that are beneficial to humans. Than useful as a food ingredient for humans, the result of plant photosynthesis as oxygen is very beneficial for other living things.
BalasHapusHumans can not live without oxygen. So people should maintain a state forest full of plants so that oxygen is always available for breathing. otherwise pristine forests will also keep the temperature of the earth to reduce the risk of global warming.