The oxygen cycle is the movement of oxygen within the atmosphere, ecosystems, and lithosphere.
OXYGEN CYCLE IN THE ATMOSPHERE AND LITHOSPHERE
STEP ONE
Plants release oxygen into the atmosphere through photosynthesis.
Plants release oxygen into the atmosphere through photosynthesis.
STEP TWO
Animals take in the oxygen through respiration. They breathe out carbon dioxide, which the plants use for photosynthesis. Step one repeats and the cycle keeps going on and on.
Animals take in the oxygen through respiration. They breathe out carbon dioxide, which the plants use for photosynthesis. Step one repeats and the cycle keeps going on and on.
OXYGEN CYCLE IN THE LITHOSPHERE
In the lithosphere, oxygen is in minerals such as silicates and oxides. Chemical weathering frees the oxygen.