The endosymbiotic (Greek: ?νδον endon "within", σ?ν syn "together" and β?ωσι? biosis "living") theories were first articulated by the Russian botanist Konstantin Mereschkowski in 1910, a ...
The oxidation state of oxygen is ?2 in almost all known compounds of oxygen. The oxidation state ?1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation stat ...
In nature, free oxygen is produced by the light-driven splitting of water during oxygenic photosynthesis. According to some estimates, Green algae and cyanobacteria in marine environments provide abou ...
At standard temperature and pressure, oxygen is a colorless, odorless gas with the molecular formula O2, in which the two oxygen atoms are chemically bonded to each other with a spin triplet electron ...
Ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site. Available ozone generators vary in the arran ...
The trivial name ozone is the most commonly used and preferred IUPAC name. The systematic names 1λ1,3λ1-trioxidane and μ-oxidodioxygen, valid IUPAC names, are constructed according to the substitut ...
Several groups of animals have formed symbiotic relationships with photosynthetic algae. These are most common in corals, sponges and sea anemones. It is presumed that this is due to the particularly ...
Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide and water using energy from light. However, not all organisms that use ligh ...
Considering what we know of the offspring groups (see phylogenetic bracketing), the LUA was a small, single-cell organism. It would have had a cell wall and a ring-shaped coil of DNA floating freely w ...
In astronomy, geology, and paleontology, bya or "b.y.a." is an initialism for billion years ago. This abbreviation is commonly used as a unit of time to denote length of time before the present. Speci ...
Amniotes, whose eggs can survive in dry environments, probably evolved in the Late Carboniferous period (330 to 298.9 Ma). The earliest fossils of the two surviving amniote groups, synapsids and sauro ...
Main article: History of the EarthThe oldest meteorite fragments found on Earth are about 4.54 billion years old; this, coupled primarily with the dating of ancient lead deposits, has put the estimate ...
Tropical rainforests can be characterized in two words: hot and wet. Mean monthly temperatures exceed 18 °C (64 °F) during all months of the year. Average annual rainfall is no less than 168 cm (66 ...
The LDG is a noticeable pattern among modern organisms that has been described qualitatively and quantitatively. It has been studied at various taxonomic levels, through different time periods and acr ...
Alpine tundra occurs at high enough altitude at any latitude. Portions of Montane grasslands and shrublands ecoregions worldwide include alpine tundra. Large regions of alpine tundra occur in the Hima ...
