The role of plants in the world is huge, actually they support life on the planet. Plants – the source of oxygen which is vital to people and animals and also is irreplaceable chemical element for a set of chemical reactions.
Plant – a life source on Earth. Be not on our planet of green foliage, there would be nothing because there would be no oxygen. Oxygen is necessary for the person for breath and, therefore, activity. The living plant "inhales", incorporates carbon dioxide, and emits vivifying oxygen.
Green color gives to leaves of plants the substance which is contained in them in a large number under the name "chlorophyll". When the beam of the sun falls on a leaf, the chlorophyll absorbs all colors of a solar range except for green. Green color is reflected a chlorophyll therefore the sheet is submitted to an eye green. As soon as chlorophyll level in leaves begins to fall or dies away absolutely (in the fall and in the early winter), color changes on yellow, red and brown when the leaf dies.
Thanks to a chlorophyll in plant cells the huge production of the various nutrients necessary for a body of human, animal, to the plant is conducted. These substances – starch, protein and sugar of which all live, mainly, is also constructed. People receive vivifying substances thanks to infinite circulation of all in the nature: they eat vegetable and animal food which is rich with the substances produced by "green factory". People consume wild plants and products of agriculture, eat animals who absorb vegetable food. For example, the cow eats in the summer a juicy grass, and in the winter – dry hay, gives milk which is processed into various useful products: sour cream, cream, oil, cottage cheese. Especially dairy food is useful to the growing-up kids who receive from it calcium and other useful substances for development and growth. The vegetable factory "works" smoothly as soon as the sunbeam concerns a plant surface. Main types of "fuel" for this work are water and carbonic acid which is always airborne much, it is exhaled by animals and people.