All living things on the planet need energy in order to survive. Humans take their food in through their mouths as they eat all types of different things. Plants on the other hand get their energy from the light given off by the sun. Three things need to be present for a plant to be able to undergo photosynthesis this includes: carbon dioxide, sunlight, and water. Plants take the carbon dioxide in through little holes in their leaves called stomata. The plant absorbs water from the soil using roots and gets that water to the rest of the body. As the sunlight passes through the leaves of the plants it travels through ton of chloroplasts found within the leaf. Within those chloroplasts the water molecules are split into hydrogen and oxygen. The oxygen leaves the leaf and the remaining hydrogen and carbon dioxide are used to form glucose which is a usable form of energy for the plant.
Approximately 85% of the world's oxygen is due to this process. That is why if the sun were to suddenly stop producing light, not only would it be dark; we would not be able to breathe much longer. These worksheets explore all aspects of the process of photosynthesis.