One of the fundamentally recognized realities in the life sciences is that the vast majority of organisms require oxygen. Although, what most people seem surprised at is that the atmosphere of the planet is only made up of twenty-one percent oxygen. Seventy-eight percent of the air that we breathe is composed of the gas nitrogen. The other one percent of the air is made up of a mixture of argon, carbon dioxide, and ozone. This mixture of gases, however, is the most ideal for sustaining life. It is ideal for sustaining life because of how it protects the earth from the dangerous light that radiates from the sun. These rays are so powerful that they can destroy any living tissue that they come in contact with. If it was not for the different gases in the atmosphere, all life on earth that came in contact with the light from the sun would be obliterated. If the amount of each gas was altered, the same thing would happen. So the amount of each gas is as important as the presence of each gas.
Therefore, the producers of earth`s oxygen are important to the environment. Most people believe that the oxygen that they are breathing comes from the trees, the grass, and all the green, photosynthetic plants that they can see around them. However, many different kinds of organisms provide the oxygen on Earth. Plants, granted, are among them, but they are not the main contributors. The organisms that yield a substantial amount of the oxygen on the planet are phytoplankton, often referred to as green algae. Now, many consider algae to be a plant, putting them in kingdom Plantae, but most biological classification schemes put them in Kingdom Protista, for algae is microscopic and tends to exist as individual cells, unlike the more complex system of cells that make up plants. However, the organisms responsible for the largest part of the oxygen produced are found in the phylum Chrysophyta, which contains more than one thousand different species. These species are collectively known as diatoms. Diatoms are a unique type of algae. They are unique in the fact that their cell walls are composed of silicon dioxide. Silicon dioxide is the main component in glass, so diatoms’ cell walls are extremely durable. So diatoms and green algae are responsible for most of the oxygen produced on the planet approximately 70-80%.
