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Trichodesmium Erythraeum
''Trichodesmium erythraeum'' is a species of cyanobacteria that are unique in being visible to the naked eye. This species is also known as " sea sawdust". It was originally discovered in 1770 by Captain Cook off the coast of Australia. Anatomy This is a prolific nitrogen-fixing and phosphorus reducing species of bacteria that fixes approximately half of the nitrogen in the food chain of the ocean and contributes to the turn over of phosphorus. Unlike other bacteria, it can also photosynthesize. This is a colonial species that forms long filaments and tends to accumulate with other ''Trichodesmium''. It is gram-negative and motile. Some of the bacteria in the colony fix the nitrogen, and others are specialized for photosynthesis. However, the two processes must be done with two of them, because the oxygen byproduct that results from photosynthesis would interfere with the nitrogen-fixing process. This is done either by, having two separate cells share resources with each other o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichodesmium
''Trichodesmium'', also called sea sawdust, is a genus of Filamentation, filamentous cyanobacteria. They are found in nutrient poor tropical and subtropical ocean waters (particularly around Australia and in the Red Sea, where they were first described by Captain Cook). ''Trichodesmium'' is a diazotroph; that is, it nitrogen fixation, fixes atmospheric nitrogen into ammonium, a nutrient used by other organisms. ''Trichodesmium'' is thought to fix nitrogen on such a scale that it accounts for almost half of the nitrogen fixation in marine systems globally. ''Trichodesmium'' is the only known diazotroph able to nitrogen fixation, fix nitrogen in daylight under aerobic conditions without the use of heterocysts. ''Trichodesmium'' can live as individual filaments, with tens to hundreds of cells strung together, or in colonies consisting of tens to hundreds of filaments clustered together. These colonies are visible to the naked eye and sometimes form blooms, which can be extensive on s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outer Space
Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is . The plasma between galaxies is thought to account for about half of the baryonic (ordinary) matter in the universe, having a number density of less than one hydrogen atom per cubic metre and a kinetic temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Studies indicate that 90% of the mass in most galaxies is in an unknown form, called dark matter, which interacts with other matter through gravitational but not electromagnetic forces. Observations s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; Tigrinya: ቀይሕ ባሕሪ ''Qeyih Bahri''; ) is a seawater inlet of the Indian Ocean, lying between Africa and Asia. Its connection to the ocean is in the south, through the Bab el Mandeb strait and the Gulf of Aden. To its north lie the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez (leading to the Suez Canal). It is underlain by the Red Sea Rift, which is part of the Great Rift Valley. The Red Sea has a surface area of roughly 438,000 km2 (169,100 mi2), is about 2250 km (1398 mi) long, and — at its widest point — 355 km (220.6 mi) wide. It has an average depth of 490 m (1,608 ft), and in the central ''Suakin Trough'' it reaches its maximum depth of . The Red Sea also has exten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizontal Gene Transfer
Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between Unicellular organism, unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the evolution of many organisms. HGT is influencing scientific understanding of higher order evolution while more significantly shifting perspectives on bacterial evolution. Horizontal gene transfer is the primary mechanism for the spread of antibiotic resistance in bacteria, and plays an important role in the evolution of bacteria that can degrade novel compounds such as human-created Bactericide, pesticides and in the evolution, maintenance, and transmission of virulence. It often involves Temperateness (virology), temperate bacteriophages and plasmids. Genes responsible for antibiotic resistance in one species of bacteria can be transferred to another species of bacteria through various m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GC Content
In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates the proportion of G and C bases out of an implied four total bases, also including adenine and thymine in DNA and adenine and uracil in RNA. GC-content may be given for a certain fragment of DNA or RNA or for an entire genome. When it refers to a fragment, it may denote the GC-content of an individual gene or section of a gene (domain), a group of genes or gene clusters, a non-coding region, or a synthetic oligonucleotide such as a primer. Structure Qualitatively, guanine (G) and cytosine (C) undergo a specific hydrogen bonding with each other, whereas adenine (A) bonds specifically with thymine (T) in DNA and with uracil (U) in RNA. Quantitatively, each GC base pair is held together by three hydrogen bonds, while AT and AU base pairs are held together by two hydrogen bonds. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of 'junk' DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The International Human Genome Project reported the sequence of the genome for ''Homo sapiens'' in 200The Human Genome Project although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. With advancements in technology that could handle sequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byproduct
A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be considered waste: for example, bran, which is a byproduct of the milling of wheat into refined flour, is sometimes composted or burned for disposal, but in other cases, it can be used as a nutritious ingredient in human food or animal feed. Gasoline was once a byproduct of oil refining that later became a desirable commodity as motor fuel. The plastic used in plastic shopping bags also started as a by-product of oil refining. In economics In the context of production, a by-product is the "output from a joint production process that is minor in quantity and/or net realizable value (NRV) when compared with the main products". Because they are deemed to have no influence on reported financial results, by-products do not receive allocations of j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filamentation
Filamentation is the anomalous growth of certain bacteria, such as ''Escherichia coli'', in which cells continue to elongate but do not divide (no septa formation). The cells that result from elongation without division have multiple chromosomal copies. In the absence of antibiotics or other stressors, filamentation occurs at a low frequency in bacterial populations (4–8% short filaments and 0–5% long filaments in 1- to 8-hour cultures). The increased cell length can protect bacteria from protozoan predation and neutrophil phagocytosis by making ingestion of cells more difficult. Filamentation is also thought to protect bacteria from antibiotics, and is associated with other aspects of bacterial virulence such as biofilm formation. The number and length of filaments within a bacterial population increases when the bacteria are exposed to different physical, chemical and biological agents (e.g. UV light, DNA synthesis-inhibiting antibiotics, bacteriophages). This is termed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanobacteria
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colony (biology)
In biology, a colony is composed of two or more conspecific individuals living in close association with, or connected to, one another. This association is usually for mutual benefit such as stronger defense or the ability to attack bigger prey. Colonies can form in various shapes and ways depending on the organism involved. For instance, the bacterial colony is a cluster of identical cells (clones). These colonies often form and grow on the surface of (or within) a solid medium, usually derived from a single parent cell. Colonies, in the context of development, may be composed of two or more unitary (or solitary) organisms or be modular organisms. Unitary organisms have determinate development (set life stages) from zygote to adult form and individuals or groups of individuals (colonies) are visually distinct. Modular organisms have indeterminate growth forms (life stages not set) through repeated iteration of genetically identical modules (or individuals), and it can be diffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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