Any green living plant absorbs carbon dioxide, extracts the carbon and releases the oxygen. The process is called photosynthesis, and is powered by sunlight. The carbon is combined with water and other trace chemicals to form complex organic substances such as starch, wood, etc. On the surface of the leaves of the plants there are a large number of tiny pores known as stomata or stoma. For photosynthesis green plants take carbon dioxide from the air. The carbon dioxide enters the leaves of the plant through the stomata present on their surface. Each stomatal pore is surrounded by a pair of guard cells. However, plants only perform photosynthesis in the green parts, like leaves and stems, but all plant cells need oxygen to respire. Cells in the leaves get plenty of oxygen from photosynthesis, but cells in the roots often need to get oxygen from the environment to stay alive.
