The oxygen cycle is the biogeochemical cycle that describes the movement of oxygen within its three main reservoirs: the atmosphere the total content of biological matter within the biosphere and the lithosphere 

Biosphere (living things)Lithosphere (Earth’s crust)Atmosphere (air)Hydrosphere(water)

The reservoirs are the locations in which oxygen is

found.

Within the biosphere and atmosphere, plants begin the oxygen cycle and animals continue it.

. Much of the oxygen present in the atmosphere is used during respiration and decay mechanisms, where animal life and bacteria consume oxygen and release carbon dioxide.

Oxygen is also cycled between the biosphere and lithosphere.

Plant release oxygen into the atmosphere as a by-product of photosynthesis.

oxygen

Plants take in carbon dioxide and water and use them to make food. Their food is simple sugar — glucose.

Animals take in oxygen through the process of respiration.

Animals then break down sugars and food.

The process that breaks apart simple food molecules to release energy.

Process → oxygen is abstracted from air, transported to cells for the oxidation of organic molecules while CO2 and H2O, the products of oxidation, are returned to the environment

In your cells, oxygen is used to split glucose apart — releasing energy, water and carbon dioxide

Carbon dioxide is released by animals and used in plants in photosynthesis.

Oxygen is balanced between the atmosphere and the ocean.

The oxygen cycle begins with plants and photosynthesis.

Through photosynthesis, plants convert the energy from the sun and water into carbohydrates and oxygen.

The ozone layer refers to a region of Earth's stratosphere that absorbs most of the Sun's UV radiation.

It contains high concentrations of ozone (O3) relative to other parts of the atmosphere.

The ozone layer is mainly found in the lower portion of the stratosphere.

Ozone depletion describes two phenomena : a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere, the ozone hole.

CFCs and other contributory substances are referred to as ozone-depleting substances .

The primary cause of ozone depletion is the presence of chlorine-containing source gases (primarily CFCs and related halocarbons).

Most of the ozone that is destroyed is in the lower stratosphere, in contrast to the much smaller ozone depletion through homogeneous gas phase reactions, which occurs primarily in the upper stratosphere.