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Plasmodial
A plasmodium is a living structure of cytoplasm that contains many nuclei, rather than being divided into individual cells each with a single nucleus. Plasmodia are best known from slime molds, but are also found in parasitic Myxosporea, and some algae such as the Chlorarachniophyta. Structure A plasmodium is an amoeboid, multinucleate, and naked mass of cytoplasm that contains many diploid nuclei. The resulting structure, a coenocyte, is created by many nuclear divisions without the process of cytokinesis, which in other organisms pulls newlydivided cells apart. In some cases, the resulting structure is a syncytium, created by the fusion of cells after division. Under suitable conditions, a plasmodium may differentiate and form fruiting bodies bearing spores at their tips. Taxonomic distribution The term plasmodium, introduced by Leon Cienkowski, usually refers to the feeding stage of slime molds; these are macroscopic mycetozoans. The multinucleate developmental stages o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slime Mold
Slime mold or slime mould is an informal name given to a polyphyletic assemblage of unrelated eukaryotic organisms in the Stramenopiles, Rhizaria, Discoba, Amoebozoa and Holomycota clades. Most are near-microscopic; those in the Myxogastria form larger plasmodial slime molds visible to the naked eye. The slime mold life cycle includes a free-living single-celled stage and the formation of spores. Spores are often produced in macroscopic multicellular or multinucleate fruiting bodies that may be formed through aggregation or fusion; aggregation is driven by chemical signals called acrasins. Slime molds contribute to the decomposition of dead vegetation; some are parasitic. Most slime molds are terrestrial and free-living, typically in damp shady habitats such as in or on the surface of rotting wood. Some myxogastrians and protostelians are aquatic or semi-aquatic. The phytomyxea are parasitic, living inside their plant hosts. Geographically, slime molds are cosmopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemitrichia Serpula 57955
''Hemitrichia'' is a genus of slime molds, of the family Trichiaceae, found within the order Trichiida. It was first described by Josef Rostafinski in 1873 and remains a well-defined genus of the slime molds. ''Hemitrichia'' species exhibit either plasmodiocarp or sporangium fruiting bodies, both of which are well-known and recognizable slime molds seen on multiple continents. This genus includes species such as H. serpula (known as the pretzel slime mold) and H. decipiens (known as salmon-eggs), both of which are widespread. Etymology ''Hemi'' comes directly from the Greek prefix hemi, meaning “half”. ''Trichia'' is combination of the Greek trichios, which refers to hair or hair-like structure and –ia, referring to a condition, leading to –''trichia'' being the condition of having hair. ''Hemitrichia'' therefore refers to the condition of partially having hair. Josef Rostafinski described ''Hemitrichia'' in the family Trichiaceae, along with another genera ''Trichia. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intracellular Parasite
Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host. They are also called intracellular pathogens. Types There are two main types of intracellular parasites: Facultative and Obligate. Facultative intracellular parasites are capable of living and reproducing in or outside of host cells. Obligate intracellular parasites, on the other hand, need a host cell to live and reproduce. Many of these types of cells require specialized host types, and invasion of host cells occurs in different ways. Facultative Facultative intracellular parasites are capable of living and reproducing either inside or outside cells. Bacterial examples include: Fungal examples include: Obligate Obligate intracellular parasites cannot reproduce outside their host cell, meaning that the parasite's reproduction is entirely reliant on intracellular resources. All viruses are obligate intracellular parasites. Bacterial examples (that affect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasmodiophorid
The plasmodiophores (also known as plasmophorids or plasmodiophorids) are a group of obligate endoparasitic protists belonging to the subphylum Endomyxa in Cercozoa. Taxonomically, they are united under a single family Plasmodiophoridae, order Plasmodiophorida, sister to the phagomyxids. Ecology and pathology Plasmodiophores are pathogenic for a wide range of organisms, but mainly green plants. The more commonly recognized are agents of plant diseases such as clubroot, powdery scab and crook root of watercress, or vectors for viruses that infect beets, peanut, monocots and potatoes, such as the potato mop-top virus or the beet necrotic yellow vein virus. Taxonomy History The plasmodiophores have historically been regarded as Fungi. The first description of plasmodiophores as a taxonomic group was in 1885 by Zopf, who united two genera '' Plasmodiophora'' and '' Tetramyxa'' in a common family “Plasmodiophoreæ”, inside the group “Monadineæ”, as part of the division ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncytia
A syncytium (; : syncytia; from Greek: σύν ''syn'' "together" and κύτος ''kytos'' "box, i.e. cell") or symplasm is a multinucleate cell that can result from multiple cell fusions of uninuclear cells (i.e., cells with a single nucleus), in contrast to a coenocyte, which can result from multiple nuclear divisions without accompanying cytokinesis. The muscle cell that makes up animal skeletal muscle is a classic example of a syncytium cell. The term may also refer to cells interconnected by specialized membranes with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential. The field of embryogenesis uses the word ''syncytium'' to refer to the coenocytic blastoderm embryos of invertebrates, such as ''Drosophila melanogaster''. Physiological examples Protists In protists, syncytia can be found in some rhizarians (e.g., chlorarachniophytes, plasmodiophorids, haplosporidians) and ace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cercozoa
Cercozoa (now synonymised with Filosa) is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead united by phylogeny, molecular phylogenies of rRNA and actin or Ubiquitin#Polyubiquitin chains, polyubiquitin. They were the first major eukaryotic group to be recognized mainly through phylogeny, molecular phylogenies. They are the natural predators of many species of bacteria. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria. Characteristics The group includes most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in many other protozoa. They show a variety of forms and have proven difficult to define in terms of structural characteristics, although their unity is strongly supported b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoplast
Protoplast (), is a biology, biological term coined by Johannes von Hanstein, Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterium, bacterial, or fungus, fungal cells by mechanical, chemical or enzymatic means. Protoplasts differ from spheroplasts in that their cell wall has been completely removed. Spheroplasts retain part of their cell wall. In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the bacterial outer membrane, outer membrane component has not. Enzymes for the preparation of protoplasts Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes: During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmosis, osmotic stress. This means cell wal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizaria
The Rhizaria are a diverse and species-rich clade of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus '' Paulinella'' in the phylum Cercozoa, they are all non-photosynthetic, but many Foraminifera and Radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, ''Guttulinopsis vulgaris'', a cellular slime mold, has been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon. Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters ( synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeletons ( thecae or loricas), which are in diffe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidospora
Cnidospora is a defunct subphylum of microscopic spore-forming parasites in the defunct phylum Protozoa. The subphylum was divided into two classes, the Myxosporidea (now classified as higher-animals, i.e. Metazoa) and the Microsporidea (now classified as fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...). References {{wikispecies Obsolete eukaryote taxa Opisthokont subphyla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidaria
Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are an uncentralized nervous system distributed throughout a gelatinous body and the presence of cnidocytes or cnidoblasts, specialized cells with ejectable flagella used mainly for envenomation and capturing prey. Their bodies consist of mesoglea, a non-living, jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell (biology), cell thick. Cnidarians are also some of the few animals that can reproduce both sexually and asexually. Cnidarians mostly have two basic body forms: swimming medusa (biology), medusae and sessility (motility), sessile polyp (zoology), polyps, both of which are radially symmetrical with mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one of the kingdom (biology)#Six kingdoms (1998), traditional eukaryotic kingdoms, along with Animalia, Plantae, and either Protista or Protozoa and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of motility, mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsporidia
Microsporidia are a group of spore-forming unicellular parasites. These spores contain an extrusion apparatus that has a coiled polar tube ending in an anchoring disc at the apical part of the spore.Franzen, C. (2005). How do Microsporidia invade cells?. Folia Parasitologica, 52(1–2), 36–40. doi.org/10.14411/fp.2005.005 They were once considered protozoans or protists, but are now known to be fungi, or a sister group to true fungi. These fungal microbes are obligate eukaryotic parasites that use a unique mechanism to infect host cells. They have recently been discovered in a 2017 Cornell study to infect Coleoptera (beetles) on a large scale. So far, about 1500 of the probably more than one million species are named. Microsporidia are restricted to animal hosts, and all major groups of animals host microsporidia. Most infect insects, but they are also responsible for common diseases of crustaceans and fish. The named species of microsporidia usually infect one host species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
