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Diplonema Nigricans
''Diplonema'' is a genus of free-living organisms in the Euglenozoa. They are distinguished from ''Rhynchopus'' in Class Diplonemea by the absence of a fully flagellate dispersive stage. Characteristics ''Diplonema'' feature two short flagella of equal length and two subapical openings. Most are free living, but there have been reported cases of infection in clams and sudden decomposition of aquarium plants. It was described initially in 1913 and later rediscovered in the 60s and called ''Isonema'', wrongly classified among euglenid Euglenids or euglenoids are one of the best-known groups of eukaryotic flagellates: single-celled organisms with flagella, or whip-like tails. They are classified in the phylum Euglenophyta, class Euglenida or Euglenoidea. Euglenids are common ...s.Brands, S.J. (comp.) 1989-2007. The Taxonomicon. Universal Taxonomic Services, Amsterdam, the Netherlands Fecha de acceso: 7 de Febrero del 2016. References Euglenozoa genera Euglenozoa { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scanning Electron Micrograph
A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition. The electron beam is scanned in a raster scan pattern, and the position of the beam is combined with the Intensity (physics), intensity of the detected signal to produce an image. In the most common SEM mode, secondary electrons emitted by atoms excited by the electron beam are detected using a secondary electron detector (Everhart–Thornley detector). The number of secondary electrons that can be detected, and thus the signal intensity, depends, among other things, on specimen topography. Some SEMs can achieve resolutions better than 1 Nanometre, nanometer. Specimens are observed in high vacuum in a Convention (norm), conventional SEM, or in low vacuum or wet conditions in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplonema Papillatum
''Diplonema'' is a genus of free-living organisms in the Euglenozoa. They are distinguished from '' Rhynchopus'' in Class Diplonemea by the absence of a fully flagellate dispersive stage. Characteristics ''Diplonema'' feature two short flagella of equal length and two subapical openings. Most are free living, but there have been reported cases of infection in clams and sudden decomposition of aquarium plants. It was described initially in 1913 and later rediscovered in the 60s and called ''Isonema'', wrongly classified among euglenid Euglenids or euglenoids are one of the best-known groups of eukaryotic flagellates: single-celled organisms with flagella, or whip-like tails. They are classified in the phylum Euglenophyta, class Euglenida or Euglenoidea. Euglenids are common ...s.Brands, S.J. (comp.) 1989-2007. The Taxonomicon. Universal Taxonomic Services, Amsterdam, the Netherlands Fecha de acceso: 7 de Febrero del 2016. References Euglenozoa genera Euglenozoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
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] |
Excavata
Excavata is an obsolete, extensive and diverse paraphyletic group of unicellular Eukaryota. The group was first suggested by Simpson and Patterson in 1999 and the name latinized and assigned a rank by Thomas Cavalier-Smith in 2002. It contains a variety of free-living and symbiotic protists, and includes some important parasites of humans such as ''Giardia'' and '' Trichomonas''. Excavates were formerly considered to be included in the now- obsolete Protista kingdom. They were distinguished from other lineages based on electron-microscopic information about how the cells are arranged (they have a distinctive ultrastructural identity). They are considered to be a basal flagellate lineage. On the basis of phylogenomic analyses, the group was shown to contain three widely separated eukaryote groups, the discobids, metamonads, and malawimonads. A current view of the composition of the excavates is given below, indicating that the group is paraphyletic. Except for some Eugleno ... [...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 four major groups, ''i.e.,'' Kinetoplastea, Diplonemea, Euglenida, 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. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplonemea
Diplonemidae is a family of biflagellated unicellular protists that may be among the more diverse and common groups of planktonic organisms in the ocean. Although this family is currently made up of three named genera; '' Diplonema'', '' Rhynchopus'', and '' Hemistasia'', there likely exist thousands of still unnamed genera. Organisms are generally colourless and oblong in shape, with two flagella emerging from a subapical pocket. They possess a large mitochondrial genome composed of fragmented linear DNA. These non-coding sequences must be massively trans-spliced, making it one of the most complicated post-transcriptional editing process known to eukaryotes. Etymology The word “Diplonemidae” come from the Greek words ‘diplo’, meaning two, and ‘nemat’, meaning thread. Together, Diplonemidae roughly translates to ‘two threads’, likely referring to the characteristic two flagella of the organism. History Primary studies done in the 1900s by Griessmann and Skuja h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchopus
''Rhynchopus'' is a genus of flagellate excavates in the class Diplonemea. They usually have flagella of different lengths and a single subapical opening with the flagellar pocket openings and adjacent feeding apparatus merging into one. When food is scarce, mobile flagellated cells are produced, suggesting the presence of a fully flagellated and dispersive phase in the life cycle, serving to distinguish Rhynchopus from Diplonema. Most species are free-living, others are symbionts and R. coscinodiscivorus is an intracellular parasite of diatoms 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 B .... Species The type species, R. amitus, has been described in Baltic plankton. It has an elongated pear shaped body, often more concave on one side than the other. A disc separates the flagel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplonemid
Diplonemidae is a family of biflagellated unicellular protists that may be among the more diverse and common groups of planktonic organisms in the ocean. Although this family is currently made up of three named genera; '' Diplonema'', '' Rhynchopus'', and '' Hemistasia'', there likely exist thousands of still unnamed genera. Organisms are generally colourless and oblong in shape, with two flagella emerging from a subapical pocket. They possess a large mitochondrial genome composed of fragmented linear DNA. These non-coding sequences must be massively trans-spliced, making it one of the most complicated post-transcriptional editing process known to eukaryotes. Etymology The word “Diplonemidae” come from the Greek words ‘diplo’, meaning two, and ‘nemat’, meaning thread. Together, Diplonemidae roughly translates to ‘two threads’, likely referring to the characteristic two flagella of the organism. History Primary studies done in the 1900s by Griessmann and Skuja h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellate
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, several derivations of the term "flagellate" (such as " dinoflagellate" and " choanoflagellate") are more formally characterized. Form and behavior Flagella in eukaryotes are supported by microtubules in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a basal body. In some flagellates, flagella direct food into a cytostome or mouth, where food is ingested. Flagella role in classifying eukaryotes. Among protoctists and microscopic animals, a flagellate is an organism with one or more flagella. Some cells in other animals may be flage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euglenid
Euglenids or euglenoids are one of the best-known groups of eukaryotic flagellates: single-celled organisms with flagella, or whip-like tails. They are classified in the phylum Euglenophyta, class Euglenida or Euglenoidea. Euglenids are commonly found in fresh water, especially when it is rich in organic materials, but they have a few marine and endosymbiotic members. Many euglenids feed by phagocytosis, or strictly by diffusion. A monophyletic subgroup known as Euglenophyceae have chloroplasts and produce their own food through photosynthesis. This group contains the carbohydrate paramylon. Euglenids split from other Euglenozoa (a larger group of flagellates) more than a billion years ago. The plastids (membranous organelles) in all extant photosynthetic species result from secondary endosymbiosis between a euglenid and a green alga. Structure Euglenoids are distinguished mainly by the presence of a type of cell covering called a pellicle. Within its taxon, the pellic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
