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Stilbonematid
Stilbonematinae is a subfamily of the nematode worm family Desmodoridae that is notable for its symbiosis with sulfur-oxidizing bacteria. Systematics Stilbonematinae Chitwood, 1936 belongs to the family Desmodoridae in the order Desmodorida. Nine genera have been described. * '' Adelphos'' Ott, 1997 * '' Catanema'' Cobb, 1920 * '' Centonema'' Leduc, 2013 * '' Eubostrichus'' Greeff, 1869 * '' Laxus'' Cobb, 1894 * '' Leptonemella'' Cobb, 1920 * '' Parabostrichus'' Tchesunov et al. 2012 * '' Robbea'' Gerlach, 1956 * '' Squanema'' Gerlach, 1963 * '' Stilbonema'' Cobb, 1920 Description Stilbonematines can be up to 10 mm long, with a club-like head. The worms are completely covered in a coat of ectosymbiotic sulfur-oxidizing bacteria except for the anterior region. The presence of the bacteria, which often contain intracellular inclusions of elemental sulfur, gives the worms a bright white appearance under incident light. They have small mouths and buccal cavities, and shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipopolysaccharide
Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by a covalent bond, and are found in the outer membrane of Gram-negative bacteria. Today, the term ''endotoxin'' is often used synonymously with LPS, although there are a few endotoxins (in the original sense of toxins that are inside the bacterial cell that are released when the cell disintegrates) that are not related to LPS, such as the so-called delta endotoxin proteins produced by '' Bacillus thuringiensis''. Lipopolysaccharides can have substantial impacts on human health, primarily through interactions with the immune system. LPS is a potent activator of the immune system and pyrogen (agent that causes fever). In severe cases, LPS can play a role in causing septic shock. In lower levels and over a longer time period, there is evidence LPS may play an important and harmful role ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Isoform
A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isoforms have unique functions. A set of protein isoforms may be formed from alternative splicings, variable promoter usage, or other post-transcriptional modifications of a single gene; post-translational modifications are generally not considered. (For that, see Proteoforms.) Through RNA splicing mechanisms, mRNA has the ability to select different protein-coding segments ( exons) of a gene, or even different parts of exons from RNA to form different mRNA sequences. Each unique sequence produces a specific form of a protein. The discovery of isoforms could explain the discrepancy between the small number of protein coding regions genes revealed by the human genome project and the large diversity of proteins seen in an organism: different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lectin
Lectins are carbohydrate-binding proteins that are highly specific for sugar groups that are part of other molecules, so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides. Lectins have a role in recognition at the cellular and molecular level and play numerous roles in biological recognition phenomena involving cells, carbohydrates, and proteins. Lectins also mediate attachment and binding of bacteria, viruses, and fungi to their intended targets. Lectins are ubiquitous in nature and are found in many foods. Some foods, such as beans and grains, need to be cooked, fermented or sprouted to reduce lectin content. Some lectins are beneficial, such as CLEC11A, which promotes bone growth, while others may be powerful toxins such as ricin. Lectins may be disabled by specific mono- and oligosaccharides, which bind to ingested lectins from grains, legumes, nightshade plants, and dairy; binding can prevent their attachment to the carbohy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stable Isotope Ratio
The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element. Hence, the plural form stable isotopes usually refers to isotopes of the same element. The relative abundance of such stable isotopes can be measured experimentally (isotope analysis), yielding an isotope ratio that can be used as a research tool. Theoretically, such stable isotopes could include the radiogenic daughter products of radioactive decay, used in radiometric dating. However, the expression stable-isotope ratio is preferably used to refer to isotopes whose relative abundances are affected by isotope fractionation in nature. This field is termed stable isotope geochemistry. Stable-isotope ratios Measurement of the ratios of naturally occurring stable isotopes (isotope analysis) plays an important role in isotope geochemistry, but stable isotopes (mostly hydrogen, carbon, nitrogen, oxygen and sulfur) are also finding uses in ecological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calvin-Benson-Bassham Cycle
The Calvin cycle, light-independent reactions, bio synthetic phase, dark reactions, or photosynthetic carbon reduction (PCR) cycle of photosynthesis is a series of chemical reactions that convert carbon dioxide and hydrogen-carrier compounds into glucose. The Calvin cycle is present in all photosynthetic eukaryotes and also many photosynthetic bacteria. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes. These reactions take the products ( ATP and NADPH) of light-dependent reactions and perform further chemical processes on them. The Calvin cycle uses the chemical energy of ATP and reducing power of NADPH from the light dependent reactions to produce sugars for the plant to use. These substrates are used in a series of reduction-oxidation reactions to produce sugars in a step-wise process; there is no direct reaction that converts several molecules of to a sugar. There are three phases to the light-independent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemosynthesis
In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrogen sulfide) or ferrous ions as a source of energy, rather than sunlight, as in photosynthesis. Chemoautotrophs, organisms that obtain carbon from carbon dioxide through chemosynthesis, are phylogenetically diverse. Groups that include conspicuous or biogeochemically-important taxa include the sulfur-oxidizing Gammaproteobacteria, the Campylobacterota, the Aquificota, the methanogenic archaea, and the neutrophilic iron-oxidizing bacteria. Many microorganisms in dark regions of the oceans use chemosynthesis to produce biomass from single-carbon molecules. Two categories can be distinguished. In the rare sites where hydrogen molecules (H2) are available, the energy available from the reaction between CO2 and H2 (leading to production of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phallodrilinae
Phallodrilinae is a subfamily of clitellate oligochaete worms. Genera The following genera are currently accepted within the subfamily Phallodrilinae. * '' Aberrantidrilus'' Martin, 2015 * '' Abyssidrilus'' Erséus, 1992 * '' Adelodrilus'' Cook, 1969 * '' Aktedrilus'' Knöllner, 1935 * '' Albanidrilus'' Erséus, 1992 * '' Atlantidrilus'' Erséus, 1982 * '' Bathydrilus'' Cook, 1970 * '' Bermudrilus'' Erséus, 1979 * '' Coralliodrilus'' Erséus, 1979 * '' Duridrilus'' Erséus, 1983 * '' Gianius'' Erséus, 1992 * ''Inanidrilus ''Inanidrilus'' is a genus of marine annelid worms, first described by Christer Erséus Christer Erséus, born 1951 in Borås, is a Swedish zoologist. He defended his doctoral dissertation in 1980 at the University of Gothenburg, where in 1991 ...'' Erséus, 1979 * '' Inermidrilus'' Erséus, 1992 * '' Jamiesoniella'' Erséus, 1981 * '' Marionidrilus'' Erséus, 1992 * '' Mexidrilus'' Erséus, 1992 * '' Milliganius'' Erséus, 1992 * '' Mitinokuidrilus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astomonema
''Astomonema'' is a genus of nematode worms in the family Siphonolaimidae. They lack a mouth or conventional digestive tract, but contain symbiotic sulfur-oxidizing bacteria that serve as their primary food source. They live in the marine interstitial habitat. Systematics The genus was first described in 1982 from specimens collected at the coast of North Carolina. It belongs to the subfamily Astomonematinae within the family Siphonolaimidae, along with another genus '' Parastomonema''; both these genera have reduced digestive systems and paired ovaries. Five species of ''Astomonema'' have been described. * ''Astomonema jenneri'' Ott, Rieger, Rieger & Enderes, 1982 * ''Astomonema obscura'' (Boucher & Helléouët, 1977) * ''Astomonema otti'' Vidakovic & Boucher, 1987 * ''Astomonema southwardorum'' Austen, Warwick & Ryan, 1993 * ''Astomonema brevicauda'' (Vitiello, 1971) Vidakovik & Boucher, 1987 (taxon inquirendum) Description Worms of the type species ''Astomonema jenner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiobenthos
Meiobenthos, also called meiofauna, are small benthic invertebrates that live in both marine and fresh water environments. The term ''meiofauna'' loosely defines a group of organisms by their size, larger than microfauna but smaller than macrofauna, rather than a taxonomic grouping. In practice, that is organisms that can pass through a 1 mm mesh but will be retained by a 45 μm mesh, but the exact dimensions will vary from researcher to researcher. Whether an organism will pass through a 1 mm mesh will also depend upon whether it is alive or dead at the time of sorting. The term ''meiobenthos'' was first coined in 1942 by Mare, but organisms that would fit into the meiofauna category have been studied since the 18th century. A comprehensive text on meiofauna is ''Introduction to the study of meiofauna'' by Higgins and Thiel (1988). Meiofaunal taxa File:Ammonia tepida.jpg, Live foraminifera ''Ammonia tepida'' (Rotaliida) File:Waterbear.jpg, Water bear ''Hypsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is a viscous colloid containing inorganic salts, antimicrobial enzymes (such as lysozymes), immunoglobulins (especially IgA), and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus serves to protect epithelial cells in the linings of the respiratory, digestive, and urogenital systems, and structures in the visual and auditory systems from pathogenic fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract. Amphibians, fish, snails, slugs, and some other invertebrates also produce external mucus from their epidermis as protection against pathogens, and to help in movement and is also produced in fish to line the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
