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Anisonemida
Anisonemidae is a small family of euglenid algae, with two accepted genera. It is the only family in the order Anisonemida. Description The family consists of single-celled organisms with a larger posterior flagellum by means of which they are able to glide. They are phagotrophic, meaning that they feed by engulfing particles of food, and are non-photosynthetic. Taxonomy The family was established by William Saville-Kent in a work published in 1880–1881. Saville-Kent used a much wider circumscription than more recent sources. Historically, phagotrophic euglenids have been treated as animals, and named under the International Code of Zoological Nomenclature, hence the family name ending "-idae". Genera , two genera are accepted: *''Anisonema'' Dujardin, 1841 *''Dinema'' Perty, 1852 (syn. ''Dinematomonas'' P.C.Silva, 1960) A third genus, ''Heteronema ''Heteronema'' is a genus of phagotrophic, flagellated euglenoids that are most widely distributed in fresh water environmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euglenozoa
Euglenozoa are a large group of flagellate Discoba. They include a variety of common free-living species, as well as a few important parasites, some of which infect humans. Euglenozoa are represented by three major clades, i.e., Kinetoplastea, Diplonema and Symbiontida. Euglenozoa are unicellular, mostly around in size, although some euglenids get up to long. Structure Most euglenozoa have two flagella, which are inserted parallel to one another in an apical or subapical pocket. In some these are associated with a cytostome or mouth, used to ingest bacteria or other small organisms. This is supported by one of three sets of microtubules that arise from the flagellar bases; the other two support the dorsal and ventral surfaces of the cell. Some other euglenozoa feed through absorption, and many euglenids possess chloroplasts, the only eukaryotes outside Diaphoretickes to do so without performing kleptoplasty, and so obtain energy through photosynthesis. These chloroplasts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteronema
''Heteronema'' is a genus of phagotrophic, flagellated euglenoids that are most widely distributed in fresh water environments.Guiry, M. D.; Guiry, G. M. (2012). “Heteronema Dujardin, 1841”. Retrieved February 14, 2019, fro/ref> This genus consists of two very distinguishable morphogroups that are phylogenetically closely related.Lax, G.; Simpson, A. G. (2013). “Combining Molecular Data with Classical Morphology for Uncultured Phagotrophic Euglenids (Excavata): A Single-Cell Approach". Journal of Eukaryotic Microbiology. 6: 615-625doi: 10.1111/jeu.12068/ref>Lee, Won J. (2011). “Free-living benthic heterotrophic euglenids from Botany Bay, Australia”. Marine Biology Research. 8 (1): 3-27doi: 10.1080/17451000.2011.596545/ref> These morphogroups are deciphered based on shape, locomotion and other ultrastructural traits. However, this genus does impose taxonomic problems due to the varying historical descriptions of ''Heteronema'' species and its similarity to the genus ''Par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinema (alga)
''Dinema'', synonym ''Dinematomonas'', is a genus of flagellated algae in the phylum Euglenozoa. Description Like other members of the family Anisonemidae, ''Dinema'' consists of single-celled organisms with a larger posterior flagellum by means of which they are able to glide. They are phagotrophic, meaning that they feed by engulfing particles of food, and are non-photosynthetic. Taxonomy The algal genus ''Dinema'' was established by Perty in 1852. It is an illegitimate name under the International Code of Nomenclature for algae, fungi, and plants. The genus name was first published in 1826 for a genus of orchids. In spite of this, it was accepted by AlgaeBase . Other sources use the genus name ''Dinematomonas'' P.C.Silva. ''Dinema'' is an acceptable name under the International Code of Zoological Nomenclature. ''Dinema'' is probably paraphyletic with respect to ''Anisonema''. Species , AlgaeBase AlgaeBase is a global species database of information on all groups of algae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euglenales
Euglenids (euglenoids, or euglenophytes, formally Euglenida/Euglenoida, ICZN, or Euglenophyceae, ICBN) are one of the best-known groups of flagellates, which are excavate eukaryotes of the phylum Euglenophyta and their cell structure is typical of that group. They are commonly found in freshwater, especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids feed by phagocytosis, or strictly by diffusion. A monophyletic group consisting of the mixotrophic Rapaza viridis (1 species) and the two groups Eutreptiales (24 species) and Euglenales (983 species) have chloroplasts and produce their own food through photosynthesis. This group is known to contain the carbohydrate paramylon. Euglenids split from other Euglenozoa more than a billion years ago. The plastids in all extant photosynthetic species is the result from secondary endosymbiosis between a phagotrophic eukaryovorous euglenid and a Pyramimonas-related green alga. Struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as '' Chlorella'', '' Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the '' Charophyta'', a division of green algae which includes, for example, '' Spirogyra'' and stoneworts. Algae that are carried by water are plankton, specifically phytoplankton. Algae constitute a polyphyletic group since they do not include a common ancestor, and although their plastids seem to have a single ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means "whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagocytosis
Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. History Phagocytosis was first noted by Canadian physician William Osler (1876), and later studied and named by Élie Metchnikoff (1880, 1883). In immune system Phagocytosis is one main mechanisms of the innate immune defense. It is one of the first processes responding to infection, and is also one of the initiating branches of an adaptive immune response. Altho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosynthesis
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in carbohydrate molecules, such as sugars and starches, which are synthesized from carbon dioxide and water – hence the name ''photosynthesis'', from the Greek ''phōs'' (), "light", and ''synthesis'' (), "putting together". Most plants, algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centers that contain green chlorophyll (and other colored) pigments/chromoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Saville-Kent
William Saville-Kent (10 July 1845 – 11 October 1908) was an English marine biologist and author. Early life Born in the town of Sidmouth in Devon, South West England on 10 July 1845, William Saville-Kent was the son of Samuel Saville Kent (7 July 1800 – 5 February 1872) and Mary Ann Windus (b. 1808 – May 1852), who was Samuel's first wife. William was the youngest of ten children from his father's first marriage. Samuel was employed as a "Factory Commissioner" for the Home Office, and inspected factories to ensure that they were properly implementing the worker safety measures regulated in the Factory Acts of 1833. As the acts sought to alleviate the harm done to children that were caused by unregulated working conditions in the factories, Samuel's “duties required him to inspect factories that employed women and children.” Despite having “ambitions for promotion,” Samuel “suffered from the effects of local gossip and disapproval,” as a consequence of him b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumscription (taxonomy)
In biological taxonomy, circumscription is the content of a taxon, that is, the delimitation of which subordinate taxa are parts of that taxon. If we determine that species X, Y, and Z belong in Genus A, and species T, U, V, and W belong in Genus B, those are our circumscriptions of those two genera. Another systematist might determine that T, U, V, W, X, Y, and Z all belong in genus A. Agreement on circumscriptions is not governed by the Codes of Zoological or Botanical Nomenclature, and must be reached by scientific consensus. A goal of biological taxonomy is to achieve a stable circumscription for every taxon. This goal conflicts, at times, with the goal of achieving a natural classification that reflects the evolutionary history of divergence of groups of organisms. Balancing these two goals is a work in progress, and the circumscriptions of many taxa that had been regarded as stable for decades are in upheaval in the light of rapid developments in molecular phylogene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Code Of Zoological Nomenclature
The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the International Commission on Zoological Nomenclature (which shares the acronym "ICZN"). The rules principally regulate: * How names are correctly established in the frame of binominal nomenclature * Which name must be used in case of name conflicts * How scientific literature must cite names Zoological nomenclature is independent of other systems of nomenclature, for example botanical nomenclature. This implies that animals can have the same generic names as plants (e.g. there is a genus ''Abronia'' in both animals and plants). The rules and recommendations have one fundamental aim: to provide the maximum universality and continuity in the naming of all animals, except where taxonomic judgment dictates otherwise. The code is meant to guide on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisonema
''Anisonema'' is a genus of colorless flagellates that occur in marine, brackish, and freshwater habitats. The cell is typically ovoid, somewhat flattened, and rigid. The name ''Anisonema'' derives from Greek for "unequal thread", in reference to the two flagella that are of unequal lengths. The shorter flagellum extends forwards and propels movement with a sweeping motion, while the longer flagellum, up to three times the length of the cell, trails behind, with jerking contractions. The genus was first named by French biologist Félix Dujardin Félix Dujardin (5 April 1801 – 8 April 1860) was a French biologist born in Tours. He is remembered for his research on protozoans and other invertebrates. Biography In 1840 he was appointed professor of geology and mineralogy at the Unive ... his 1841 ''Histoire naturelle des zoophytes. Infusoires, comprenant la physiologie et la classification de ces animaux, et la manière de les étudier à l'aide du microscope''. , there ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
