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Endosymbionts
An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals, and bacterial endosymbionts that provide essential nutrients to insects. Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.2 billion years ago an archaeon absorbed a bacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living eukaryotic cells. Approximately 1 billion years ago, some of those cells absorbed cyanobacteria that eventually became chloroplasts, organelles that produce energy from sunlight. Approximately 100 million years ago, a lineage of amoeba in the genus '' Paulinella'' independently engulfed a cyanobacterium that evolved to be functionally synonymous with traditiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endosymbiosis
An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualism (biology), mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside Coral reef, reef-building corals, and bacterial endosymbionts that provide essential nutrients to insects. Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.2 billion years ago an archaeon absorbed a bacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living Eukaryote, eukaryotic cells. Approximately 1 billion years ago, some of those cells absorbed cyanobacteria that eventually became chloroplasts, organelles that produce energy from sunlight. Approximately 100 million years ago, a lineage of amoeba in the genus ''Paulinella'' independently engulfed a cyanobacterium that evolved to be f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mansonella Perstans
''Mansonella perstans'' is a filarial (arthropod-borne) nematode (roundworm), transmitted by tiny blood-sucking fly, flies called midges. ''Mansonella perstans'' is one of two filarial nematodes that causes serous cavity filariasis in humans. The other filarial nematode is ''Mansonella ozzardi''. ''M. perstans'' is widespread in many parts of sub-Saharan Africa, parts of Central America, Central and South America, and the Caribbean. Compared to infections with other filarial parasites such as ''Wuchereria bancrofti'', ''Brugia malayi'', and ''Loa loa'', ''Mansonella'' infections are relatively mild. However, the pathogenicity of ''M. perstans'' infection has been recently reconsidered in various studies. These studies have demonstrated that ''M. perstans'' has the ability to induce a variety of clinical features, including angioedema Calabar-like swellings, pruritus, fever, headache, eosinophilia, and abdominal pain. The overall disability among populations in regions where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolbachia
''Wolbachia'' is a genus of gram-negative bacteria infecting many species of arthropods and filarial nematodes. The symbiotic relationship ranges from parasitism to obligate mutualism. It is one of the most common parasitic microbes of arthropods, and is possibly the most widespread reproductive parasite bacterium in the biosphere. Its interactions with hosts are complex and highly diverse across different host species. Some host species cannot reproduce, or even survive, without ''Wolbachia'' colonisation. One study concluded that more than 16% of neotropical insect species carry bacteria of this genus, and as many as 25 to 70% of all insect species are estimated to be potential hosts. History The first organism classified as ''Wolbachia'' was discovered in 1924 by Marshall Hertig and Simeon Burt Wolbach in the common house mosquito. They described it as "a somewhat pleomorphic, rodlike, Gram-negative, intracellular organism hatapparently infects only the ovaries and te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the Radiant energy, energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UCYN-A
''Candidatus'' Atelocyanobacterium thalassa, also referred to as UCYN-A, is a nitrogen-fixing species of cyanobacteria commonly found in measurable quantities throughout the world's oceans and some seas. Members of ''A. thalassa'' are spheroid in shape and are 1-2 μm in diameter, and provide nitrogen to ocean regions by fixing non biologically available atmospheric nitrogen into biologically available ammonium that other marine microorganisms can use. Unlike many other cyanobacteria, the genome of ''A. thalassa'' does not contain genes for RuBisCO, photosystem II, or the TCA cycle. Consequently, ''A. thalassa'' lacks the ability to fix carbon via photosynthesis. Some genes specific to the cyanobacteria group are also absent from the ''A. thalassa'' genome despite being an evolutionary descendant of this group. With the inability to fix their own carbon, ''A. thalassa'' are obligate symbionts that have been found within photosynthetic picoeukaryote algae. Most notably, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paulinella
''Paulinella'' is a genus of at least eleven species including both freshwater and marine amoeboids. Like many members of euglyphids it is covered by rows of siliceous scales, and use filose pseudopods to crawl over the substrate of the benthic zone. Its most famous members are the three photosynthetic species ''P. chromatophora'', ''P. micropora'' and ''P. longichromatophora'', the first two being freshwater forms and the third a marine form, which have recently (in evolutionary terms) taken on a cyanobacterium as an endosymbiont. As a result they are no longer able to perform phagocytosis like their non-photosynthetic relatives. ''P. chromatophora'' was discovered in sediments of the river Rhine on Christmas Eve 1894 by German biologist Robert Lauterborn, who named it Paulinella after his stepmother Pauline. The event to permanent endosymbiosis probably occurred with a cyanobiont. The resulting organelle is a photosynthetic plastid that is often referred to as a 'cyanelle' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplasts
A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which capture the Radiant energy, energy from sunlight and convert it to chemical energy and release oxygen. The chemical energy created is then used to make sugar and other organic molecules from carbon dioxide in a process called the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in some unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. Chloroplasts are highly dynamic—they circulate and are moved around within cells. Their behavior is strongly influenced by environmental factors like light color and intensity. Chloroplasts cannot be made anew by the plant cell and must ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen-fixing
Nitrogen fixation is a chemical process by which molecular dinitrogen () is converted into ammonia (). It occurs both biologically and abiological nitrogen fixation, abiologically in chemical industry, chemical industries. Biological nitrogen fixation or ''diazotrophy'' is catalyzed by enzymes called nitrogenases. These enzyme complexes are encoded by the Nif gene, ''Nif'' genes (or ''Nif'' homologs) and contain iron, often with a second metal (usually molybdenum, but sometimes vanadium). Some nitrogen-fixing bacteria have symbiotic relationships with plants, especially legumes, mosses and aquatic ferns such as ''Azolla''. Looser non-symbiotic relationships between diazotrophs and plants are often referred to as associative, as seen in nitrogen fixation on rice roots. Nitrogen fixation occurs between some termites and fungus, fungi. It occurs naturally in the air by means of NOx, NOx production by lightning. Fixed nitrogen is essential to life on Earth. Organic compounds such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterium
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the fixation of nitrogen from the atmosphere. The nutrient cycle includes the decomposition of dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulphide and methane, to energy. Bacteria also live in mutualistic, commensal and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's Biomass (ecology), biomass. They generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion tonnes of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms are a significant component of marine sediment, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes. Diatoms are unicellular organisms: they occur either as solitary cells or in Colony (biology), colonies, which can take the shape of ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Braarudosphaera Bigelowii
''Braarudosphaera bigelowii'' is a coastal coccolithophore in the fossil record going back 100 million years to the Late Cretaceous. Coccolithophore The Family (biology), family Braarudosphaeraceae consist of single-celled coastal phytoplanktonic algae with calcareous scales with five-fold symmetry, called pentaliths. With 12 sides, it has a Regular dodecahedron, regular dodecahedral structure, approximately 10 micrometers across. Nitroplast ''B. bigelowii'' has a nitroplast organelle, originated some 100 million years ago from a cyanobacterial endosymbiont called Atelocyanobacterium thalassa, UCYN-A2, which allows ''B. bigelowii to'' Nitrogen fixation, fix nitrogen and convert it into Plant nutrition, compounds useful for cell growth. This phenomenon is previously known from diatoms in the family ''Rhopalodiaceae'', where a nitrogen fixing and non-photosynthetic cyanobacterial endosymbiont, a diazoplast, provides the photosynthetic host cell with nitrogen. Name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
