The chloroplasts contain a green pigment called chlorophyll. This green material gives the leaf its colour. With the help of chlorophyll and energy from the sun, a leaf can change lifeless substances into food. This process is called photosynthesis. The water is gathered by the plant's roots.
Carbon dioxide is gathered from the air through the stomata.
This sugar is mixed with water and sent to other parts of the plant to be used by the plant as food. The oxygen is released into the air through the stomata.