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Crude oil, a transformed biogenic substance Natural gum, a secretion from Hevea brasiliensis. A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, [1] it has developed to encompass any constituents, secretions, and metabolites of plants or animals. [2]
In addition to the presently accumulated emissions, there will be significant additional emissions during this century, even in the most ambitious low-emission scenarios. BECCS has therefore been suggested as a technology to reverse the emission trend and create a global system of net negative emissions.
Silicic acid, Si(OH) 4, is a hydrated form of silica found only as an unstable solution in water, yet it plays a central role in the silica cycle. [ 1 ] Silicifiers are organisms that use silicic acid to precipitate biogenic silica , SiO 2 .
Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.
Some sources of a trace gas are biogenic processes, outgassing from solid Earth, ocean emissions, industrial emissions, and in situ formation. [1] A few examples of biogenic sources include photosynthesis, animal excrements, termites, rice paddies, and wetlands. Volcanoes are the main source for trace gases from solid earth.
A lot of water is needed for the excretion of ammonia, about 0.5 L of water is needed per 1 g of nitrogen to maintain ammonia levels in the excretory fluid below the level in body fluids to prevent toxicity. [citation needed] Thus, the marine organisms excrete ammonia directly into the water and are called ammonotelic. [2]
They are unique among phytoplankton, because they require Si in the form of silicic acid (Si(OH)4) for growth and production of their frustules, which are made of biogenic silica (bSiO2) and act as ballast. [105] [107] According to the reports of Miklasz and Denny, [108] the sinking velocities of diatoms can range from 0.4 to 35 m/day.
Marine biogenic calcification is the production of calcium carbonate by organisms in the global ocean.. Marine biogenic calcification is the biologically mediated process by which marine organisms produce and deposit calcium carbonate minerals to form skeletal structures or hard tissues.