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Oxygen began building up in the atmosphere at approximately 1.85 Ga. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 ...
Oxygen is a chemical element; it has symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the most abundant element in Earth's crust, and after hydrogen and helium, it ...
Oxygen evolution. Oxygen evolution is the process of generating molecular oxygen (O 2) by a chemical reaction, usually from water. Oxygen evolution from water is effected by oxygenic photosynthesis, electrolysis of water, and thermal decomposition of various oxides. The biological process supports aerobic life.
The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, [2] was a time interval during the Earth 's Paleoproterozoic era when the Earth's atmosphere and shallow seas first experienced a rise in the concentration of free oxygen. [3]
Cellular respiration is the process of which biological fuels are oxidised in the presence of an inorganic electron acceptor such as oxygen to produce large amounts of energy, to drive the bulk production of ATP. Anaerobic respiration is used by microorganisms either bacteria or archaea in which neither oxygen (aerobic respiration) nor pyruvate ...
Breathing. Real-time magnetic resonance imaging of the human thorax during breathing. X-ray video of a female American alligator while breathing. Breathing (spiration[1] or ventilation) is the rhythmical process of moving air into (inhalation) and out of (exhalation) the lungs to facilitate gas exchange with the internal environment, mostly to ...
Most deuterium was created in the Big Bang or in supernovae, so its uneven distribution throughout the protosolar nebula was effectively "locked in" early in the formation of the Solar System. [34] By studying the different isotopic ratios of Earth and of other icy bodies in the Solar System, the likely origins of Earth's water can be researched.
Oxygen cycle refers to the movement of oxygen through the atmosphere (air), biosphere (plants and animals) and the lithosphere (the Earth’s crust). The oxygen cycle demonstrates how free oxygen is made available in each of these regions, as well as how it is used. The oxygen cycle is the biogeochemical cycle of oxygen atoms between different ...