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Coccoliths are individual plates of calcium carbonate formed by coccolithophores (single-celled algae such as Emiliania huxleyi) which are arranged around them in a coccosphere. Calcium carbonate is a chemical compound, with chemical formula CaCO3. ...
Coccolithophores are single-celled algae belonging to the haptophytes. ...
A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ...
Binomial name Emiliania huxleyi (Hay & Mohler in Hay, Mohler, Roth, Schmidt & Boudreaux, 1967) Emiliania huxleyi is a species of coccolithophore, single-celled phytoplankton that are covered with uniquely ornamented calcite disks. ...
Formation and composition
The coccoliths are either dispersed following death and breakup of the coccosphere, or are shed continually by some species. They sink through the water column to form an important part of the deep-sea sediments (depending on the water depth). Thomas Huxley was the first to observe and name coccoliths in sedimentary samples. Coccoliths are composed of calcium carbonate as the mineral calcite and are the main constituent of chalk deposits such as the white cliffs of Dover. Sediment is any particulate matter that can be transported by fluid flow and which eventually is deposited as a layer of solid particles on the bed or bottom of a body of water or other liquid. ...
Thomas Huxley Thomas Henry Huxley F.R.S. (May 4, 1825 - June 29, 1895) was a British biologist, known as Darwins Bulldog for his defence of Charles Darwins theory of evolution. ...
Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ...
The Needles, part of the extensive Southern England Chalk Formation Chalk is a soft, white, porous form of limestone composed of the mineral calcite. ...
The white cliffs of Dover The white cliffs of Dover, immortalized in popular song and verse (by Vera Lynn, Kate Smith, Matthew Arnold, Eric Johnson and others), are cliffs facing the Strait of Dover near the major English port town of Dover, in the county of Kent, and form part...
Types There are two main types of coccoliths, heterococcoliths and holococcoliths. Heterococcoliths are formed of a radial array of elaborately shaped crystal units. Holococcoliths are formed of minute (ca 0.1 micrometre) calcite rhombohedra arranged in continuous arrays. The two coccolith types were originally thought to be produced by different families of coccolithophores. Now, however, it is known through a mix of observations on field samples and laboratory cultures, that the two coccolith types are produced by the same species but at different life cycle phases. Heterococcoliths are produced in the diploid life-cycle phase and holococcoliths in the haploid phase.
Purpose Although coccoliths are energetically expensive to produce, their purpose is unclear. Hypotheses include defence against grazing by zooplankton or infection by bacteria or viruses; maintenance of buoyancy; release of carbon dioxide for photosynthesis; and to filter out harmful UV light. Photomontage of plankton organisms Plankton is the aggregate community of weakly swimming but mostly drifting small organisms that inhabit the water column of the ocean, seas, and bodies of freshwater. ...
Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ...
A common alternate meaning of virus is computer virus. ...
In physics, buoyancy is an upward force on an object immersed in a fluid (i. ...
Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ...
Leaf. ...
Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ...
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