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Vorticella Campanula
The protozoon ''Vorticella campanula'' is found in freshwater ponds, lakes, rivers, and streams with aquatic vegetation. It has a global distribution. ''Vorticella campanula'' is solitary and not colonial but usually social, several of them being found together. ''Vorticella campanula'' is a sedentary (fixed) form. It is commonly attached by a long highly contractile stalk to some submerged objects like weeds, animals, or stones. ''Vorticella campanula'' is often found in large groups. All the individuals in the group, however, remain free and independent of each other. Most ''Vorticella'' are found in abundance in stagnant water rich in decaying organic matter and feed largely on bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ..., but ''Vorticella campanula'' live onl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Protozoon
Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically, protozoans were regarded as "one-celled animals". When first introduced by Georg Goldfuss, in 1818, the taxon Protozoa was erected as a class within the Animalia, with the word 'protozoa' meaning "first animals", because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae. This classification remained widespread in the 19th and early 20th century, and even became elevated to a variety of higher ranks, including phylum, subkingdom, kingdom, and then sometimes included within the paraphyletic Protoctista or Protista. By the 1970s, it became usual to require that all taxa be monophyletic (derived from a common ancestor that would also be regarded as protozoan) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Social
Social organisms, including human(s), live collectively in interacting populations. This interaction is considered social whether they are aware of it or not, and whether the exchange is voluntary or not. Etymology The word "social" derives from the Latin word ''socii'' ("allies"). It is particularly derived from the Italian '' Socii'' states, historical allies of the Roman Republic (although they rebelled against Rome in the Social War of 91–87 BC). Social theorists In the view of Karl Marx,Morrison, Ken. ''Marx, Durkheim, Weber. Formations of modern social thought'' human beings are intrinsically, necessarily and by definition social beings who, beyond being "gregarious creatures", cannot survive and meet their needs other than through social co-operation and association. Their social characteristics are therefore to a large extent an objectively given fact, stamped on them from birth and affirmed by socialization processes; and, according to Marx, in producing and reproduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sedentary
Sedentary lifestyle is a lifestyle type, in which one is physically inactive and does little or no physical movement and/or exercise. A person living a sedentary lifestyle is often sitting or lying down while engaged in an activity like socializing, watching TV, playing video games, reading or using a mobile phone or computer for much of the day. A sedentary lifestyle contributes to poor health quality, diseases as well as many preventable causes of death. Sitting time is a common measure of a sedentary lifestyle. A global review representing 47% of the global adult population found that the average person sits down for 4.7 to 6.5 hours a day with the average going up every year. The CDC found that 25.3% of all American adults are physically inactive. Screen time is a term for the amount of time a person spends looking at a screen such as a television, computer monitor, or mobile device. Excessive screen time is linked to negative health consequences. Definition Seden ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Contractile
Contractility refers to the ability for self-contraction, especially of the muscles or similar active biological tissue *Contractile ring in cytokinesis *Contractile vacuole *Muscle contraction **Myocardial contractility *See contractile cell for an overview of cell types in humans. See also *motility Motility is the ability of an organism to move independently using metabolism, metabolic energy. This biological concept encompasses movement at various levels, from whole organisms to cells and subcellular components. Motility is observed in ... {{SIA Cell movement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Stagnant Water
Water stagnation occurs when water stops flowing for a long period of time. Stagnant water can be a significant environmental hazard. Dangers Malaria and dengue are among the main dangers of still water, which can become a breeding ground for the mosquitoes that transmit these diseases. Stagnant water can be dangerous because it provides a better incubator than running water for many kinds of infectious pathogens. Stagnant water can be contaminated with human and animal feces, particularly in deserts or other areas of low rainfall. Water stagnation for as little as six days can completely change bacterial community composition and increase cell count. Stagnant water may be classified into the following basic, although overlapping, types: * Water body stagnation (stagnation in swamp, lake, lagoon, river, etc.) * Surface and ground water stagnation * Trapped water stagnation. The water may be trapped in human artifacts (discarded cans, plant pots, tires, dug-outs, roo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, 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, Hot spring, 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 nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, 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, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Oligohymenophorea
The Oligohymenophorea are a large class of ciliates. There is typically a ventral groove containing the mouth and distinct oral cilia, separate from those of the body. These include a paroral membrane to the right of the mouth and membranelles, usually three in number, to its left. The cytopharynx is inconspicuous and never forms the complex cyrtos found in similar classes. Body cilia generally arise from monokinetids, with dikinetids occurring in limited distribution over part of the body. Characteristics In most groups the body cilia are uniform and often dense, while the oral cilia are inconspicuous and sometimes reduced, but among the peritrichs almost the opposite is the case. Members are widely distributed, and include many free-living (typically fresh-water, but many marine) and symbiotic forms. Most are microphagous, grazing on smaller organisms swept into the mouth by the cilia, but various other feeding habits occur. In one group, the astomes, the mouth a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Articles Containing Video Clips
Article often refers to: * Article (grammar), a grammatical element used to indicate definiteness or indefiniteness * Article (publishing) An article or piece is a written work published in a Publishing, print or electronic media, electronic medium, for the propagation of news, research results, academic analysis or debate. News A news article discusses current or recent news of e ..., a piece of nonfictional prose that is an independent part of a publication Article(s) may also refer to: Government and law * Elements of treaties of the European Union * Articles of association, the regulations governing a company, used in India, the UK and other countries; called articles of incorporation in the US * Articles of clerkship, the contract accepted to become an articled clerk * Articles of Confederation, the predecessor to the current United States Constitution * Article of impeachment, a formal document and charge used for impeachment in the United States * Article of ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Protists Described In 1831
A protist ( ) or protoctist is any Eukaryote, eukaryotic organism that is not an animal, Embryophyte, land plant, or fungus. Protists do not form a Clade, natural group, or clade, but are a Paraphyly, paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic rank, taxonomic kingdom (biology), kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroup (biology), supergroups, such as Archaeplastida (photoautotrophs that includes land plants), SAR supergroup, SAR, Obazoa (which includes fungi and animals), Amoebozoa and "Excavata". Protists represent an extremely large genetic diversity, genetic and ecological diversity in all environments, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Taxa Named By Christian Gottfried Ehrenberg
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
