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Other elements form diatomic molecules when evaporated, but these diatomic species repolymerize when cooled. Heating ("cracking") elemental phosphorus gives diphosphorus (P 2). Sulfur vapor is mostly disulfur (S 2). Dilithium (Li 2) and disodium (Na 2) [4] are known in the gas phase. Ditungsten (W 2) and dimolybdenum (Mo 2) form with sextuple ...
Since diatoms form an important part of the food of molluscs, tunicates, and fishes, the alimentary tracts of these animals often yield forms that are not easily secured in other ways. Diatoms can be made to emerge by filling a jar with water and mud, wrapping it in black paper and letting direct sunlight fall on the surface of the water.
Medlin and co-workers erected a new class, Mediophyceae (which could be re-ranked a subclass if diatoms as a whole are ranked as a class rather than a phylum) for the "polar centric" diatoms, which they consider to be more closely related to the pennate rather than to other centric diatoms, a concept which has been followed or further adapted ...
The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin, a fiber most commonly found in cell walls of plants. [1] [2] This layer is actually composed of several types of polysaccharides. [3]
Nitrogenase has three different forms (Nif, Anf, and Vnf) that correspond with the metal found in the active site of the protein (Molybdenum, Iron, and Vanadium respectively). [42] Marine metal abundances over Earth’s geologic timeline are thought to have driven the relative abundance of which form of nitrogenase was most common. [ 43 ]
High concentrations of nitrates and phosphates increase the amount of inorganic carbon in the form of bicarbonate fixed by S. costatum. [8] [60] Iron is an essential nutrient in primary production as it is used in processes of photosynthesis and is under high competition among marine diatoms.
GeO 2 is readily taken up by diatoms and leads to silicon being substituted by germanium in biochemical processes within the diatoms, causing a significant reduction of the diatoms' growth rate or even their complete elimination, with little effect on non-diatom algal species. For this application, the concentration of germanium dioxide ...
Phaeodactylum tricornutum is one of a handful of diatoms whose genome has been sequenced. As of 2023, P. tricornutum is the only diatom for which a telomere-to-telomere genome assembly exists. [9] P. tricornutum is a diploid with 25 pairs of nuclear chromosomes. P. tricornutum has emerged as a potential microalgal energy source. It grows ...