Photosynthesis is the process where by all green plants such as green algae manufacture their own food form simple raw material such as water， carbon dioxide etc in the presence of sunlight to form starch and water. The following are the necessary conditions for photosynthesis process;-
(1) Sunlight; light energy from the sun help to breakdown water molecule in the leaves into hydrogen ions and oxygen ions by the process called photolysis.
(2) Chlorophyll; help the plants to trap light energy from the sun and convert it into chemical energy (ATP).
(3) Carbo dioxide; Carbon dioxide from respiration combine with hydrogen ions from water combine together in the presence of chemical energy (ATP) to form starch and water.
(4) Water; Water molecule from the soil broken down into hydrogen ion and oxygen ions by the presence of light from the sun by the process called photolysis.