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Endosymbiotic Events
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 traditional ch ... [...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] |
Eukaryote
The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of Outline of life forms, life forms alongside the two groups of prokaryotes: the Bacteria and the Archaea. Eukaryotes represent a small minority of the number of organisms, but given their generally much larger size, their collective global biomass is much larger than that of prokaryotes. The eukaryotes emerged within the archaeal Kingdom (biology), kingdom Asgard (Archaea), Promethearchaeati and its sole phylum Promethearchaeota. This implies that there are only Two-domain system, two domains of life, Bacteria and Archaea, with eukaryotes incorporated among the Archaea. Eukaryotes first emerged during the Paleoproterozoic, likely as Flagellated cell, flagellated cells. The leading evolutiona ... [...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] |
Wuchereria Bancrofti
''Wuchereria bancrofti'' is a filarial (arthropod-borne) nematode (roundworm) that is the major cause of lymphatic filariasis. It is one of the three parasitic worms, together with ''Brugia malayi'' and '' B. timori'', that infect the lymphatic system to cause lymphatic filariasis. These filarial worms are spread by a variety of mosquito vector species. ''W. bancrofti'' is the most prevalent of the three and affects over 120 million people, primarily in Central Africa and the Nile delta, South and Central America, the tropical regions of Asia including southern China, and the Pacific islands. If left untreated, the infection can develop into lymphatic filariasis. In rare conditions, it also causes tropical pulmonary eosinophilia. No vaccine is commercially available, but high rates of cure have been achieved with various antifilarial regimens, and lymphatic filariasis is the target of the World Health Organization Global Program to Eliminate Lymphatic Filariasis with the aim to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fission (biology)
Fission, in biology, is the division of a single entity into two or more parts and the regeneration of those parts to separate entities resembling the original. The object experiencing fission is usually a cell (biology), cell, but the term may also refer to how organisms, bodies, populations, or species split into discrete parts. The fission may be ''binary fission'', in which a single organism produces two parts, or ''multiple fission'', in which a single entity produces multiple parts. Binary fission Organisms in the domain (biology), domains of Archaea and Bacteria reproduce with binary fission. This form of asexual reproduction and cell division is also used by some organelles within eukaryote, eukaryotic organisms (e.g., mitochondrion, mitochondria). Binary fission results in the reproduction of a living prokaryote, prokaryotic cell (biology), cell (or organelle) by dividing the cell into two parts, each with the potential to grow to the size of the original. Fission of pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitosis
Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identical cells in which the total number of chromosomes is maintained. Mitosis is preceded by the S phase of interphase (during which DNA replication occurs) and is followed by telophase and cytokinesis, which divide the cytoplasm, organelles, and cell membrane of one cell into two new cell (biology), cells containing roughly equal shares of these cellular components. The different stages of mitosis altogether define the mitotic phase (M phase) of a cell cycle—the cell division, division of the mother cell into two daughter cells genetically identical to each other. The process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next. These stages are preprophase (specific to plant ce ... [...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] |
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] |
Nitroplast
A nitroplast is an organelle found in certain species of algae, particularly in the marine algae ''Braarudosphaera bigelowii''. It plays a crucial role in nitrogen fixation, a process previously thought to be exclusive to bacteria and archaea. The discovery of nitroplasts has significant implications for both cellular biology and agricultural science. Discovery In 1998, Jonathan Zehr, an ocean ecologist at the University of California, Santa Cruz, and his colleagues found an unknown DNA sequence that appeared to be for an unknown nitrogen-fixing Cyanobacteria, cyanobacterium in the Pacific Ocean, which they called UCYN-A (unicellular cyanobacterial group A). At the same time, Kyoko Hagino, a paleontologist at Kōchi University, Kochi University, was working to culture the host organism, ''B. bigelowii''. The existence of nitroplasts was first proposed by researchers studying the interaction between ''B. bigelowii'' and UCYN-A in 2012. Initially, it was hypothesized that UCYN-A ... [...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] |
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] |
