The oxygen cycle is the
biogeochemical cycle that describes the movement of
oxygen within and between its three main reservoirs: the
atmosphere, the biosphere, and the
lithosphere. The main driving factor of the oxygen cycle is
photosynthesis, which is responsible for the modern Earth's atmosphere and life as we know it. Because of the vast amounts of oxygen in the atmosphere, even if all photosynthesis were to cease it would take between 5,000 to 2.5 million years (unknown reference) to strip out more or less all oxygen.
See more at Wikipedia.org...
Cyclic movement of oxygen in different chemical forms from the environment, to organisms, and then back to the environment.
Free Download Now!
