query: name the two forms of polymorphism in cnidarian

pos: Cnidaria Cnidarians, particularly the polyp and medusa forms, or of zooids within colonial organisms like those in Hydrozoa. In Hydrozoans, colonial individuals arising from individuals zooids will take on separate tasks. For example, in "Obelia" there are feeding individuals, the gastrozooids; the individuals capable of asexual reproduction only, the gonozooids, blastostyles and free-living or sexually reproducing individuals, the medusae. These "nettle cells" function as harpoons, since their s remain connected to the bodies of the cells by threads. Three types of cnidocytes are known: The main components of a cnidocyte are: It is difficult to study the firing mechanisms of cnidocytes

pos: Aiptasia symbioses, a biological phenomenon crucial to the survival of corals and coral reef ecosystems. The dependence of coral reefs on the health of the symbiosis is dramatically illustrated by the devastating effects experienced by corals due to the loss of algal symbionts in response to environmental stress, a phenomenon known as coral bleaching. Species in the genus "Aiptasia" include: Cnidarian species are found in one of two body forms: the polyp and the medusae. Some alternate between these two forms during their life cycle. In the case of "Aiptasia", and all anthozoans, the body form is the polyp. The body

pos: Sea pansy Sea pansy The sea pansy is a species of colonial cnidarian in the family Renillidae. It is native to warm continental shelf waters of the Western Hemisphere. It is frequently found washed ashore on northeast Florida beaches following northeasterly winds or rough surf conditions. It also can often be found living intertidally completely buried in the sand. Its predator is the striped sea slug, "Armina tigrina". The sea pansy is a collection of polyps with different forms and functions. A single, giant polyp up to two inches in diameter forms the anchoring stem (peduncle). This peduncle can be distended to

pos: Ptilosarcus gurneyi Ptilosarcus gurneyi Ptilosarcus gurneyi, the orange sea pen or fleshy sea pen, is a species of sea pen in the family Pennatulidae. It is native to the northeastern Pacific Ocean where it lives in deep water anchored by its base in sand or mud. It has received its common name because of its resemblance to a quill in a bottle of ink. The orange sea pen is a colonial cnidarian, the individual polyps having their own specialised functions. One, the primary polyp, loses its tentacles and forms both the stalk of the colony (known as the rachis), and the bulbous

pos: Zoanthus sociatus Zoanthus sociatus Zoanthus sociatus, commonly known as the green sea mat or button polyp, is a zoanthid usually found in shallow reef zones of tropical regions from Caribbean to southeastern Brazil. "Z. sociatus" is currently being studied for its use against human lymphatic parasites. "Zoanthus sociatus" has nematocysts, which makes it a cnidarian. As it has polyp morphology, it is an anthozoan. It also has tentacles in multiples of 6, so it falls under the subclass Hexacorallia. It is in the order Zoanthidea due to its lack of a calcium carbonate skeleton. Forms elaborate piecemeal mats of normally green to

pos: Planula Planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species. Some groups of Nemerteans too produce larvae that are very similar to the planula. The planula forms either from the fertilized egg of a medusa, as is the case in scyphozoans and some hydrozoans, or from a polyp, as in the case of anthozoans. Depending on the species, the planula either metamorphoses directly into a free-swimming, miniature version of the mobile adult form, or navigates through the water until it reaches a hard substrate (many may prefer specific substrates) where it anchors and grows

pos: Ediacaran biota was embarked upon more than once on this planet". In 2018 analysis of ancient sterols was taken as evidence that one of the period's most-prominent and iconic fossils, Dickinsonia, was an early animal., but cholesterol also is known in Glomeromycota fungi . Since the most primitive eumetazoans—multi-cellular animals with tissues—are cnidarians, the first attempt to categorise these fossils designated them as jellyfish and sea pens. However, more recent discoveries have established that many of the circular forms formerly considered "cnidarian medusa" are actually holdfasts – sand-filled vesicles occurring at the base of the stem of upright frond-like Ediacarans. A notable

pos: Planula into a polyp. The miniature-adult types include many open-ocean scyphozoans. The attaching types include all anthozoans with a planula stage, many coastal scyphozoans, and some hydrozoans. The planulae of the subphylum Medusozoa have no mouth, and no digestive tract, and are unable to feed themselves, while those of Anthozoa can feed. Planula larvae swim with the aboral end (the end opposite the mouth) in front. Planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species. Some groups of Nemerteans too produce larvae that are very similar to the planula. The planula forms either from

pos: Xyloplax medusiformis Xyloplax medusiformis Xyloplax medusiformis is a sea daisy, a member of an unusual group of marine taxa belonging to the phylum Echinodermata. It is found at bathyal depths in waters around New Zealand. It was first described in 1986 by Baker, Rowe and Clark and is the type taxon of the genus "Xyloplax". Its generic name derives from the Greek "xylo" meaning wood and its specific name was chosen because its morphology superficially resembles that of a cnidarian medusa. Specimens of "Xyloplax medusiformis" were first discovered by accident when a submersible craft was being used to collect samples of wood

neg: Polymorphism (biology) term. In biology, polymorphism has been given a specific meaning, being distinguishable from monomorphism (having only one form). A more specific term, when only two forms occur, is dimorphism. Polymorphism crosses several discipline boundaries, including ecology and genetics, evolution theory, taxonomy, cytology, and biochemistry. Different disciplines may give the same concept different names, and different concepts may be given the same name. For example, there are the terms established in ecological genetics by E.B. Ford (1975), and for classical genetics by John Maynard Smith (1998). The shorter term morphism may be more accurate than polymorphism, but is not often used.

neg: Polymorphism (biology) Polymorphism (biology) Polymorphism in biology and zoology is the occurrence of two or more clearly different morphs or forms, also referred to as alternative "phenotypes", in the population of a species. To be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population (one with random mating). The term polyphenism can be used to clarify that the different forms arise from the same genotype. Genetic polymorphism is a term used somewhat differently by geneticists and molecular biologists to describe certain mutations in the genotype, such as single nucleotide polymorphisms that may

neg: Pteridinium cnidarian, but it appears that it is, at best, only very distantly related to any known cnidarian. Its relation to other known Ediacaran biota is no clearer. There are no identified related forms, although there is some vague resemblance to other Ediacaran forms such as "Dickinsonia" and "Spriggina" that share some of its enigmatic characteristics, such as the "staggered" or glide symmetry of its units, or triradial symmetry otherwise only seen in trilobozoans like "Tribrachidium". "Pteridinium" has no known descendants. Pteridinium Pteridinium is an erniettomorph found in a number of Precambrian deposits worldwide. It is a member of the Ediacaran

neg: Polymorphism in Lepidoptera Polymorphism in Lepidoptera Many types of polymorphism can be seen in the insect order Lepidoptera. Polymorphism is appearance of forms or "morphs" differing in colour and number of attributes within a single species. In Lepidoptera, polymorphism can be seen not only between individuals in a population, but also between the sexes as "sexual dimorphism", between geographically separated populations in "geographical polymorphism" and also between generations flying at different seasons of the year ("seasonal polymorphism"). It also includes the phenomenon of mimicry when mimetic morphs fly alongside non-mimetic morphs in a population of a particular species. Polymorphism occurs both at specific

neg: Polymorphism in Lepidoptera level with heritable variation in the overall morphological design of individuals as well as in certain specific morphological or physiological traits within a species. Genetic polymorphism occurs when the morphs are a result of genetic determination only. The extreme case of genetic polymorphism is that of the papilionid great Mormon ("Papilio memnon"), where four male forms and many as twenty-six female forms are reported. This species, and others in its genus, have been extensively studied for understanding the genetic basis for polymorphism and Batesian mimicry. In the case of the scarlet tiger moth "Callimorpha" ("Panaxia") "dominula" (family Arctiidae), which is

neg: Polymorphism (biology) results, in summary: Number of species demonstrating natural selection: 141. Number showing quantitative traits: 56. Number showing polymorphic traits: 62. Number showing both Q and P traits: 23. This shows that polymorphisms are found to be at least as common as continuous variation in studies of natural selection, and hence just as likely to be part of the evolutionary process. Polymorphism (biology) Polymorphism in biology and zoology is the occurrence of two or more clearly different morphs or forms, also referred to as alternative "phenotypes", in the population of a species. To be classified as such, morphs must occupy the

neg: Polymorphism (biology) being researched. Since all polymorphism has a genetic basis, "genetic polymorphism" has a particular meaning: The definition has three parts: a) sympatry: one interbreeding population; b) discrete forms; and c) not maintained just by mutation. In simple words, the term polymorphism was originally used to describe variations in shape and form that distinguish normal individuals within a species from each other. These days, geneticists use the term genetic polymorphism to describe the inter-individual, functionally silent differences in DNA sequence that make each human genome unique. Genetic polymorphism is actively and steadily maintained in populations by natural selection, in contrast to

neg: Polymorphism (computer science) data type" like the generalized type from which such specializations are made. Parametric polymorphism is ubiquitous in functional programming, where it is often simply referred to as "polymorphism". The following example in Haskell shows a parametrized list data type and two parametrically polymorphic functions on them: Parametric polymorphism is also available in several object-oriented languages. For instance, templates in C++ and D, or under the name generics in C# and Java: John C. Reynolds (and later Jean-Yves Girard) formally developed this notion of polymorphism as an extension to lambda calculus (called the polymorphic lambda calculus or System F). Any parametrically

neg: Sinaloan pocket mouse Color Polymorphism Coat color is a genetic polymorphism. Many different coat colors are seen between species of pocket mice and even within the same population because of differences in their genotype. Multiple aspects of the environment put selective pressures on pocket mice to adapt their coat colors. Variation in coat color between pocket mice can be a selective advantage for two main reasons: concealment and regulation of physiological processes. Concealment offers a large selective advantage for pocket mice that are able to successfully hide from potential predators, also known as Crypsis. Pocket mice generally show two forms of crypsis: camouflage

neg: Polymorphism (biology) not always correspond to a phenotype, but always corresponds to a branch in the genetic tree. See below. Polymorphism is common in nature; it is related to biodiversity, genetic variation, and adaptation. Polymorphism usually functions to retain variety of form in a population living in a varied environment. The most common example is sexual dimorphism, which occurs in many organisms. Other examples are mimetic forms of butterflies (see mimicry), and human hemoglobin and blood types. According to the theory of evolution, polymorphism results from evolutionary processes, as does any aspect of a species. It is heritable and is modified by

neg: Polymorphism (materials science) polymorphism. Polymorphism can also result from the existence of different conformers of the same molecule in conformational polymorphism. In pseudopolymorphism the different crystal types are the result of hydration or solvation. This is more correctly referred to as solvomorphism as different solvates have different chemical formulae. An example of an organic polymorph is glycine, which is able to form monoclinic and hexagonal crystals. Silica is known to form many polymorphs, the most important of which are; α-quartz, β-quartz, tridymite, cristobalite, coesite, and stishovite. A classical example is the pair of minerals, calcite and aragonite, both forms of calcium carbonate. An

neg: E. B. Ford Ford also went on in 1955 to write "Moths" in the same series, one of only a few to have authored more than one book in the series. Ford became Professor, and then Emeritus Professor of Ecological Genetics, University of Oxford. He was a Fellow of All Souls College, and Honorary Fellow of Wadham College. He was elected FRS in 1946, and awarded the Darwin Medal in 1954. E.B. Ford worked for many years on genetic polymorphism. Polymorphism in natural populations is frequent; the key feature is the occurrence together of two or more discontinuous forms of a species in

neg: Crystal engineering under nano confinement remains an attractive interest of this field. More recently, multicomponent networks are also studied that are formed by the application of crystal engineering principles. Although, there is a very high influence of the underlying substrate on the formation of the two dimensional assemblies, at least in a few cases, a relation was found between 2D assemblies and the bulk crystal structures. Polymorphism is the phenomenon wherein the same chemical compound exists in different crystal forms. In the initial days of crystal engineering, polymorphism was not properly understood and incompletely studied. Today, it is one of the most

neg: Polymorphism (biology) populations. An example of a botanical genetic polymorphism is heterostyly, in which flowers occur in different forms with different arrangements of the pistils and the stamens. The system is called heteromorphic self-incompatibility, and the general 'strategy' of stamens separated from pistils is known as herkogamy. Pin and thrum heterostyly occurs in dimorphic species of "Primula", such as "P. vulgaris". There are two types of flower. The "pin" flower has a long style bearing the stigma at the mouth and the stamens halfway down; and the "thrum" flower has a short style, so the stigma is halfway up the tube and

neg: Polymorphism (biology) ways in which two or more genes may combine to produce a coordinated change in more than one characteristic (for instance, in mimicry). Unlike the supergene, epistatic genes do not need to be closely linked or even on the same chromosome. Both pleiotropism and epistasis show that a gene need not relate to a character in the simple manner that was once supposed. Although a polymorphism can be controlled by alleles at a single locus (e.g. human ABO blood groups), the more complex forms are controlled by supergenes consisting of several tightly linked genes on a single chromosome. Batesian mimicry

neg: Damselfly the Eurasian bluets, the males are bright blue with black markings, while the females are usually predominantly green or brown with black. A few dimorphic species show female-limited polymorphism, the females being in two forms, one form distinct and the other with the patterning as in males. The ones that look like males, andromorphs, are usually under a third of the female population but the proportion can rise significantly and a theory that explains this response suggests that it helps overcome harassment by males. Some Coenagrionid damselflies show male-limited polymorphism, an even less understood phenomenon. In general, damselflies are smaller

neg: Polyphenism exploit variations in their environment. Some nematode worms can develop either into adults or into resting dauer larvae according to resource availability. A polyphenism is a biological mechanism that causes a trait to be polyphenic. For example, crocodiles possess a sex-determining polyphenism, and therefore their gender is a polyphenic trait. When polyphenic forms exist at the same time in the same panmictic (interbreeding) population they can be compared to genetic polymorphism. With polyphenism the switch between morphs is environmental, but with genetic polymorphism the determination of morph is genetic. These two cases have in common that more than one morph

neg: Zoraptera palps have five segments, labial palps three, in both the most distal segment is enlarged. Immature nymphs resemble small adults. Each species shows polymorphism. Most individuals are the apterous form or "morph", with no wings, no eyes, and no or little pigmentation. A few females and even fewer males are in the alate form with relatively large membranous wings that can be shed at a basal fracture line. Alates also have compound eyes and ocelli, and more pigmentation. This polymorphism can be observed already as two forms of nymphs. Wingspan can be up to , and the wings can be

neg: Rs1805054 Rs1805054 In genetics, Rs1805054, also called C267T, is a name used for a specific genetic variation, a single nucleotide polymorphism (SNP), in the HTR6 gene. It is one of the few investigated polymorphisms of its gene. C267T is a synonymous polymorphism. As of 2008 meta-analysis of the polymorphism and Alzheimer's disease indicates that there probably is no association between the two, though individual studies report such an association, e.g., a Chinese study found an association with late-onset Alzheimer's disease. Another reported association in neuropsychiatry disorders is with treatment response in depression. C267T has also been examined in relation to personality

neg: Lipid polymorphism Lipid polymorphism Polymorphism in biophysics is the ability of lipids to aggregate in a variety of ways, giving rise to structures of different shapes, known as "phases". This can be in the form of spheres of lipid molecules (micelles), pairs of layers that face one another (lamellar phase, observed in biological systems as a lipid bilayer), a tubular arrangement (hexagonal), or various cubic phases (Fd3m, Im3m, Ia3m, Pn3m, and Pm3m being those discovered so far). More complicated aggregations have also been observed, such as rhombohedral, tetragonal and orthorhombic phases. It forms an important part of current academic research in the

neg: Rs1805054 traits, with a Korean study finding some evidence for an association with the trait "self-transcendence". A Japanese study reported no association with personality traits using the NEO PI-R personality inventory. Rs1805054 In genetics, Rs1805054, also called C267T, is a name used for a specific genetic variation, a single nucleotide polymorphism (SNP), in the HTR6 gene. It is one of the few investigated polymorphisms of its gene. C267T is a synonymous polymorphism. As of 2008 meta-analysis of the polymorphism and Alzheimer's disease indicates that there probably is no association between the two, though individual studies report such an association, e.g., a

neg: Polymorphism (materials science) oxides. Table below gives the polymorphic forms of key functional binary metal oxides, such as: CrO, CrO, FeO, AlO, BiO, TiO, SnO, ZrO, MoO, WO, InO. Polymorphism is important in the development of pharmaceutical ingredients. Many drugs receive regulatory approval for only a single crystal form or polymorph. In a classic patent case the pharmaceutical company GlaxoSmithKline defended its patent for the polymorph type II of the active ingredient in Zantac against competitors while that of the polymorph type I had already expired. Polymorphism in drugs can also have direct medical implications. Medicine is often administered orally as a crystalline

neg: Crystal structure period vectors Polymorphism is the occurrence of multiple crystalline forms of a material. It is found in many crystalline materials including polymers, minerals, and metals. According to Gibbs' rules of phase equilibria, these unique crystalline phases are dependent on intensive variables such as pressure and temperature. Polymorphism is related to allotropy, which refers to elemental solids. The complete morphology of a material is described by polymorphism and other variables such as crystal habit, amorphous fraction or crystallographic defects. Polymorphs have different stabilities and may spontaneously convert from a metastable form (or thermodynamically unstable form) to the stable form at a

neg: Allotropy elements is just a special case of the phenomenon of polymorphism known for compounds, and proposed that the terms allotrope and allotropy be abandoned and replaced by polymorph and polymorphism. Although many other chemists have repeated this advice, IUPAC and most chemistry texts still favour the usage of allotrope and allotropy for elements only. Allotropes are different structural forms of the same element and can exhibit quite different physical properties and chemical behaviours. The change between allotropic forms is triggered by the same forces that affect other structures, i.e., pressure, light, and temperature. Therefore, the stability of the particular allotropes

neg: Function overloading particular call is resolved at compile time. In the Java programming language, function overloading is also known as compile-time polymorphism and static polymorphism. Function overloading should not be confused with forms of polymorphism where the choice is made at runtime, e.g. through virtual functions, instead of statically. Example: function overloading in C++ In the above example, the volume of each component is calculated using one of the three functions named "volume", with selection based on the differing number and type of actual parameters. Constructors, used to create instances of an object, may also be overloaded in some object-oriented programming languages.

neg: XBase++ XBase++ Xbase++ is an object oriented programming language which has multiple inheritance and polymorphism. It is based on the XBase language dialect and conventions. It is 100% Clipper compatible language supporting multiple inheritance, polymorphism, object oriented programming. It supports the xBase data types, including Codeblocks. With Xbase++ it is possible to generate applications for Windows NT, 95, 98, Me, 2000, XP, VISTA and Windows 7. Xbase++ supports the old commands @SAY/GET to define data entry forms as well as a graphic editor to create data entry forms similar to Visual FoxPro. It also has a visual development environment, support for

neg: Polymorphism in Lepidoptera sexual dimorphism is that of adult females of many Psychidae species who have only vestigial wings, legs, and mouthparts as compared to the adult males who are strong fliers with well-developed wings and feathery antennae. Geographical polymorphism is where geographical isolation causes a divergence of a species into different morphs. A good example is the Indian white admiral ("Limenitis procris") which has five forms, each geographically separated from the other by large mountain ranges. An even more dramatic showcase of geographical polymorphism is the Apollo butterfly ("Parnassius apollo"). Due to the Apollos living in small local populations, having no contact

neg: Parametric polymorphism Visual Basic .NET and Delphi have each introduced "generics" for parametric polymorphism. Some implementations of type polymorphism are superficially similar to parametric polymorphism while also introducing ad hoc aspects. One example is C++ template specialization. The most general form of polymorphism is "higher-rank impredicative polymorphism". Two popular restrictions of this form are restricted rank polymorphism (for example, rank-1 or "prenex" polymorphism) and predicative polymorphism. Together, these restrictions give "predicative prenex polymorphism", which is essentially the form of polymorphism found in ML and early versions of Haskell. In a "prenex polymorphic" system, type variables may not be instantiated with polymorphic types.

neg: Polymorphism (biology) it should be taught. It provides after all the proof of evolution." Current interpretation of the available evidence is that the peppered moth is in fact a valid example of natural selection and adaptation. It illustrates a polymorphic species maintaining adaptation to a varied and sometimes changing environment. "Adalia bipunctata", the two-spotted ladybird, is highly polymorphic. Its basic form is red with two black spots, but it has many other forms, the most important being melanic, with black elytra and red spots. The curious fact about this morphism is that, although the melanic forms are more common in industrial areas,

neg: Radiata unmistakable bilateral symmetry as larvae, and are now in the Bilateria. Ctenophores exhibit biradial or rotational symmetry, defined by tentacular and pharyngeal axes, on which two anal canals are located in two diametrically opposed quadrants. Some species within the cnidarian class Anthozoa are bilaterally symmetric (For example, "Nematostella vectensis"). It has been suggested that bilateral symmetry may have evolved before the split between Cnidaria and Bilateria, and that the radially symmetrical cnidarians have secondarily evolved radial symmetry, meaning the bilaterality in cnidarian species like "N. vectensis" has a primary origin. The differing definitions assigned by zoologists are listed in the

neg: Polymorphism (computer science) Polymorphism (computer science) In programming languages and type theory, polymorphism is the provision of a single interface to entities of different types or the use of a single symbol to represent multiple different types. The most commonly recognised major classes of polymorphism are: Interest in polymorphic type systems developed significantly in the 1960s, with practical implementations beginning to appear by the end of the decade. "Ad hoc polymorphism" and "parametric polymorphism" were originally described in Christopher Strachey's "Fundamental Concepts in Programming Languages", where they are listed as "the two main classes" of polymorphism. Ad hoc polymorphism was a feature of

neg: Chromosomal polymorphism Chromosomal polymorphism In genetics, chromosomal polymorphism is a condition where one species contains members with varying chromosome counts or shapes. Polymorphism is a general concept in biology where more than one version of a trait is present in a population. In some cases of differing counts, the difference in chromosome counts is the result of a single chromosome undergoing fission, where it splits into two smaller chromosomes, or two undergoing fusion, where two chromosomes join to form one. This condition has been detected in many species. "Trichomycterus davisi", for example, is an extreme case where the polymorphism was present within

neg: Ad hoc polymorphism its name, but by the combination of its name and the number, order and types of its parameters. This type of polymorphism is common in object-oriented programming languages, many of which allow operators to be overloaded in a manner similar to functions (see operator overloading). Some languages that are not dynamically typed and lack ad hoc polymorphism (including type classes) have longer function names such as codice_1, codice_2, etc. This can be seen as advantage (more descriptive) or a disadvantage (overly verbose) depending on one's point of view. An advantage that is sometimes gained from overloading is the appearance of

neg: Apicomplexa highly derived cnidarian animals), and the Microsporidia (now known to be derived from fungi). Sometimes, the name Sporozoa is taken as a synonym for the Apicomplexa, or occasionally as a subset. All members of this phylum have an infectious stage—the sporozoite—which possesses three distinct structures in an apical complex. The apical complex consists of a set of spirally arranged microtubules (the conoid), a secretory body (the rhoptry) and one or more polar rings. Additional slender electron-dense secretory bodies (micronemes) surrounded by one or two polar rings may also be present. This structure gives the phylum its name. A further group

neg: C++ above. Compile-time polymorphism does not allow for certain run-time decisions, while runtime polymorphism typically incurs a performance penalty. Function overloading allows programs to declare multiple functions having the same name but with different arguments (i.e. "ad hoc" polymorphism). The functions are distinguished by the number or types of their formal parameters. Thus, the same function name can refer to different functions depending on the context in which it is used. The type returned by the function is not used to distinguish overloaded functions and would result in a compile-time error message. When declaring a function, a programmer can specify for

neg: Coelenterazine Coelenterazine Coelenterazine is a luciferin, light-emitting molecules, found in many aquatic organisms across eight phyla. It is the substrate of many luciferases such as "Renilla reniformis" luciferase (Rluc), "Gaussia" luciferase (Gluc), and photoproteins, including aequorin, and obelin. Coelenterazine was simultaneously isolated and characterized by two groups studying the luminescent organisms sea pansy ("Renilla reniformis") and the cnidarian "Aequorea victoria", respectively. Both groups unknowingly discovered that the same compound was used in both luminescent systems, however the name of the molecule was given after the now-obsolete phylum coelenterata. Likewise, the two main metabolites – coelenteramide and coelenteramine – were named after

neg: Aurelia (cnidarian) Aurelia (cnidarian) Aurelia is a genus of scyphozoan jellyfish, commonly called moon jellies. There are at least 13 species in the genus "Aurelia" including many that are still not formally described. It has been suggested that "Aurelia" is the best-studied group of gelatinous zooplankton, with "Aurelia aurita" the best-studied species in the genus; two other species, "Aurelia labiata" and "Aurelia limbata" have also been investigated (studies summarized by Arai). Since most previous studies of "Aurelia" were done without the benefit of genetic identification, one cannot positively attribute the results of most research to the species named. Species of "Aurelia" can

neg: OpenSNP valuable forms of social interaction and support in cases where members of a community conduct PLR together, for example, patients suffering from the same illness."The name of the project is inspired by single nucleotide polymorphism (SNP), which is a DNA variation at a specific location on a strand. Scientists have discovered that there is a correlation between certain SNPs and genetic predispositions such as Mendelian disease. The code of the project is on GitHub and the CSS is licensed under the Apache 2.0 license. Since openSNP is an open-sourced social network that is readily available on the internet, there have

neg: Chromosomal polymorphism All forms of chromosomal polymorphism can be viewed as a step towards speciation. Polymorphisms will generally result in a level of reduced fertility, because some gametes from one parent cannot successfully combine with all gametes of the other parent. However, when both parents contain matching chromosomal patterns, this obstacle does not occur. Further mutations in one group will not flow as rapidly into the other group as they do within the group in which it originally occurred. Further mutations can also cause absolute infertility. If an interbreeding population contains one group in which (for example) chromosomes A and B have

neg: Phase (matter) but can also exist as the cubic ice I, the rhombohedral ice II, and many other forms. Polymorphism is the ability of a solid to exist in more than one crystal form. For pure chemical elements, polymorphism is known as allotropy. For example, diamond, graphite, and fullerenes are different allotropes of carbon. When a substance undergoes a phase transition (changes from one state of matter to another) it usually either takes up or releases energy. For example, when water evaporates, the increase in kinetic energy as the evaporating molecules escape the attractive forces of the liquid is reflected in a

neg: Type system only implement a data structure such as a list or an associative array once, rather than once for each type of element with which they plan to use it. For this reason computer scientists sometimes call the use of certain forms of polymorphism "generic programming". The type-theoretic foundations of polymorphism are closely related to those of abstraction, modularity and (in some cases) subtyping. In "duck typing", a statement calling a method codice_11 on an object does not rely on the declared type of the object; only that the object, of whatever type, must supply an implementation of the method called,

neg: Lepidoptera air into the trachea. Air is taken in through spiracles along the sides of the abdomen and thorax supplying the trachea with oxygen as it goes through the lepidopteran's respiratory system. Three different tracheaes supply and diffuse oxygen throughout the species' bodies. The dorsal tracheae supply oxygen to the dorsal musculature and vessels, while the ventral tracheae supply the ventral musculature and nerve cord, and the visceral tracheae supply the guts, fat bodies, and gonads. Polymorphism is the appearance of forms or "morphs", which differ in color and number of attributes within a single species. In Lepidoptera, polymorphism can be

neg: Viceroy (butterfly) area of wing pattern genes explains how mimetic phenotypes are not broken up during recombination during sexual reproduction. Viceroys display geographic color polymorphism, which occurs when the viceroy butterflies are observed having different color forms in different regions of their territory. Color polymorphism is hypothesized to be affected by interaction between the viceroy, monarch and queen's overlapping environments. In the northern areas of their region, where monarchs predominate, viceroys are lighter, while in southern Florida, they are darker due to queens being more abundant than monarchs. Viceroy (butterfly) The viceroy ("Limenitis archippus") is a North American butterfly that ranges through

neg: Polymorphism (biology) feeding of the grubs. Polymorphism with an environmental trigger is called polyphenism. The polyphenic system does have a degree of environmental flexibility not present in the genetic polymorphism. However, such environmental triggers are the less common of the two methods. Investigation of polymorphism requires use of both field and laboratory techniques. In the field: And in the laboratory: Without proper field-work, the significance of the polymorphism to the species is uncertain and without laboratory breeding the genetic basis is obscure. Even with insects, the work may take many years; examples of Batesian mimicry noted in the nineteenth century are still

neg: Polymorphism (computer science) with structural types. It allows the usage of all values whose types have certain properties, without losing the remaining type information. A related concept is "polytypism" (or "data type genericity"). A polytypic function is more general than polymorphic, and in such a function, "though one can provide fixed ad hoc cases for specific data types, an ad hoc combinator is absent". Polymorphism can be distinguished by when the implementation is selected: statically (at compile time) or dynamically (at run time, typically via a virtual function). This is known respectively as "static dispatch" and "dynamic dispatch," and the corresponding forms of

neg: XBase++ as Clipper substitute empowered the creation of third party libraries and the creation of Clipper syntax compilers. XBase++ Xbase++ is an object oriented programming language which has multiple inheritance and polymorphism. It is based on the XBase language dialect and conventions. It is 100% Clipper compatible language supporting multiple inheritance, polymorphism, object oriented programming. It supports the xBase data types, including Codeblocks. With Xbase++ it is possible to generate applications for Windows NT, 95, 98, Me, 2000, XP, VISTA and Windows 7. Xbase++ supports the old commands @SAY/GET to define data entry forms as well as a graphic editor to

neg: Polymorphism (biology) of genetic polymorphism occurs in the white-lipped snail "Cepaea hortensis", a close relative of the grove snail. In Iceland, where there are no song thrushes, a correlation has been established between temperature and colour forms. Banded and brown morphs reach higher temperatures than unbanded and yellow snails. This may be the basis of the physiological selection found in both species of snail. The scarlet tiger moth "Callimorpha" ("Panaxia") "dominula" (family Arctiidae) occurs in continental Europe, western Asia and southern England. It is a day-flying moth, noxious-tasting, with brilliant warning colour in flight, but cryptic at rest. The moth is colonial

neg: Polymorphism (materials science) diffraction patterns. Various conditions in the crystallisation process is the main reason responsible for the development of different polymorphic forms. These conditions include: Despite the potential implications, polymorphism is not always well understood. In 2006 a new crystal form of maleic acid was discovered 124 years after the first crystal form was studied. Maleic acid is a chemical manufactured on a very large scale in the chemical industry and is a salt forming component in medicine. The new crystal type is produced when a co-crystal of caffeine and maleic acid (2:1) is dissolved in chloroform and when the solvent is

neg: NAD(P)H dehydrogenase (quinone 1) polymorphism of the "NQO1" gene (NQO1*2), found homozygous in 4% to 20% of different populations, has found to be connected with different forms of cancer and a lowered efficiency of some chemotherapeutics like mitomycin C. This single nucleotide polymorphism leads to a proline serine exchange on position 187. NAD(P)H dehydrogenase [quinone] 1 P187S has been shown to have a lowered activity and stability. Crystallographic and nuclear magnetic resonance data show that the reason for this different behaviour is found in a flexible C-terminus of the protein leading to a destabilization of the whole protein. Recent pharmacological research suggests feasibility of

neg: Boloceroides daphneae Boloceroides daphneae Boloceroides daphneae is a cnidarian which occurs in the depths of the East Pacific Rise and was described in 2006. While the species is currently recognized as a sea anemone, a phylogenetic study was completed in 2014, in which three genes of mitochondrial DNA and two genes from the nucleus of over a hundred different sea anemones were compared, suggesting that the species instead belongs in a new order. A new genus, "Relicanthus", was named to accommodate this alternate classification. The specific name "daphneae" is after Daphne Gail Fautin, "in honor of her contributions to actinarian systematics." "B.

neg: Double dispatch be achieved without employing the visitor pattern. This is done by using traditional polymorphism while also casting the argument to "dynamic". The run-time binder will choose the appropriate method overload at run-time. This decision will take into consideration the run-time type of the object instance (polymorphism) as well as the run-time type of the argument. The Eiffel programming language can bring the concept of agents to bear on the double-dispatch problem. The example below applies the agent language construct to the double-dispatch problem. Consider a problem domain with various forms of SHAPE and of drawing SURFACE upon which to draw

neg: Ad hoc polymorphism polymorphism, in which polymorphic functions are written without mention of any specific type, and can thus apply a single abstract implementation to any number of types in a transparent way. This classification was introduced by Christopher Strachey in 1967. Ad hoc polymorphism is a dispatch mechanism: control moving through one named function is dispatched to various other functions without having to specify the exact function being called. Overloading allows multiple functions taking different types to be defined with the same name; the compiler or interpreter automatically ensures that the right function is called. This way, functions appending lists of integers,

neg: Ad hoc polymorphism specialization, e.g., a function with the same name can be implemented in multiple different ways, each optimized for the particular data types that it operates on. This can provide a convenient interface for code that needs to be specialized to multiple situations for performance reasons. The downside is that the type system cannot guarantee the consistency of the different implementations. Since overloading is done at compile time, it is not a substitute for late binding as found in subtyping polymorphism. The previous section notwithstanding, there are other ways in which "ad hoc" polymorphism can work out. Consider for example the

neg: Myrmecia (ant) that provide excellent vision, and a powerful sting that they use to kill prey. Each of their eyes contains 3,000 facets, making them the second largest in the ant world. Size varies widely, ranging from in length. The largest "Myrmecia" species is "M. brevinoda", with workers measuring ; "M. brevinoda" workers are also the largest in the world. Almost all species are monomorphic, but "M. brevinoda" is the only known species where polymorphism exists. It is well known that two worker subcastes exist, but this does not distinguish them as two different polymorphic forms. This may be due to the

neg: Ad hoc polymorphism classes inheriting from the hierarchy of classes. These are effective techniques which can be used to take advantage of Smalltalk's powerful reflection capabilities. Similar arrangements are also possible in languages such as Self and Newspeak. Imagine an operator codice_3 that may be used in the following ways: To handle these six function calls, four different pieces of code are needed—or "three", if strings are considered to be lists of characters: Thus, the name codice_3 actually refers to three or four completely different functions. This is an example of "overloading". Ad hoc polymorphism In programming languages, ad hoc polymorphism is a

neg: Generic function Generic function In computer programming, a generic function is a function defined for polymorphism. In statically typed languages (such as C++ and Java), the term "generic functions" refers to a mechanism for "compile-time polymorphism" (static dispatch), specifically parametric polymorphism. These are functions defined with TypeParameters, intended to be resolved with compile time type information. The compiler uses these types to instantiate suitable versions, resolving any function overloading appropriately. In some systems for object-oriented programming such as the Common Lisp Object System (CLOS) and Dylan, a "generic function" is an entity made up of all methods having the same name. Typically

neg: Trilobozoa Trilobozoa Trilobozoa ("three-lobed animals") is a taxon of extinct organisms which displayed tri-radial symmetry. Fossils of trilobozoans are restricted to marine strata of the Late Ediacaran period — prior to the Cambrian explosion of more modern life forms. The taxonomic affinities of this groups are open to debate. Ivantsov and Fedonkin (2002) place them among the cnidarians. They reasoned that since the conulate "Vendoconularia" exhibited six-fold symmetry, the conularids — then regarded as a sister group to the scyphozoan cnidarians — must be nested within the trilobozoa, making the trilobozoan group part of the cnidarian phylum. Most trilobozoans were disk-shaped,

neg: Polymorphism (computer science) polymorphism are accordingly called "static polymorphism" and "dynamic polymorphism". Static polymorphism executes faster, because there is no dynamic dispatch overhead, but requires additional compiler support. Further, static polymorphism allows greater static analysis by compilers (notably for optimization), source code analysis tools, and human readers (programmers). Dynamic polymorphism is more flexible but slower—for example, dynamic polymorphism allows duck typing, and a dynamically linked library may operate on objects without knowing their full type. Static polymorphism typically occurs in ad hoc polymorphism and parametric polymorphism, whereas dynamic polymorphism is usual for subtype polymorphism. However, it is possible to achieve static polymorphism with

neg: Chromosomal polymorphism fused, and another population in which chromosomes B and C have fused, both populations will be able to interbreed with the parent population. However, the two subpopulations will not be able to breed successfully with each other if the doubling of chromosome B is fatal. Similar difficulties will occur for incompatible translocations of material. Chromosomal polymorphism In genetics, chromosomal polymorphism is a condition where one species contains members with varying chromosome counts or shapes. Polymorphism is a general concept in biology where more than one version of a trait is present in a population. In some cases of differing counts,

neg: Eilhard Mitscherlich in the direction of the optic axes of selenite. His investigation, also in 1826, of the two crystalline modifications of sulfur threw much light on the fact that the two minerals calcite and aragonite have the same composition but different crystalline forms, a property which Mitscherlich called polymorphism. In 1833 Mitscherlich made a series of careful determinations of the vapor densities of a large number of volatile substances, confirming the law of Gay-Lussac. In 1833-34, Mitscherlich investigated the synthesis of diethyl ether from ethanol and sulfuric acid. Through his careful studies, he realized that the acid was not being consumed

neg: Polymorphism (biology) natural selection. In polyphenism, an individual's genetic makeup allows for different morphs, and the switch mechanism that determines which morph is shown is environmental. In genetic polymorphism, the genetic makeup determines the morph. The term polymorphism also refers to the occurrence of structurally and functionally more than two different types of individuals, called zooids, within the same organism. It is a characteristic feature of cnidarians. For example, "Obelia" has feeding individuals, the gastrozooids; the individuals capable of asexual reproduction only, the gonozooids, blastostyles; and free-living or sexually reproducing individuals, the medusae. Although in general use, polymorphism is a very broad

neg: Polymorphism (biology) form of intellectual property). Three mechanisms may cause polymorphism: Selection, whether natural or artificial, changes the frequency of morphs within a population; this occurs when morphs reproduce with different degrees of success. A genetic (or balanced) polymorphism usually persists over many generations, maintained by two or more opposed and powerful selection pressures. Diver (1929) found banding morphs in "Cepaea nemoralis" could be seen in prefossil shells going back to the Mesolithic Holocene. Non-human apes have similar blood groups to humans; this strongly suggests that this kind of polymorphism is ancient, at least as far back as the last common ancestor

neg: Parametric polymorphism Parametric polymorphism In programming languages and type theory, parametric polymorphism is a way to make a language more expressive, while still maintaining full static type-safety. Using parametric polymorphism, a function or a data type can be written generically so that it can handle values "identically" without depending on their type. Such functions and data types are called generic functions and generic datatypes respectively and form the basis of generic programming. For example, a function codice_1 that joins two lists can be constructed so that it does not care about the type of elements: it can append lists of integers, lists

neg: Single-strand conformation polymorphism different allelic states, as well as heterozygous individuals that should each demonstrate distinct patterns in an electrophoresis experiment. SSCP is also widely used in virology to detect variations in different strains of a virus, the idea being that a particular virus particle present in both strains will have undergone changes due to mutation, and that these changes will cause the two particles to assume different conformations and, thus, be differentiable on an SSCP gel. Single-strand conformation polymorphism Single-strand conformation polymorphism (SSCP), or single-strand "chain" polymorphism, is defined as a conformational difference of single-stranded nucleotide sequences of identical length as induced

neg: Natural deduction ask is whether it is possible for programs to depend on types, or any other combination. There are many kinds of answers to such questions. A popular approach in type theory is to allow programs to be quantified over types, also known as "parametric polymorphism"; of this there are two main kinds: if types and programs are kept separate, then one obtains a somewhat more well-behaved system called "predicative polymorphism"; if the distinction between program and type is blurred, one obtains the type-theoretic analogue of higher-order logic, also known as "impredicative polymorphism". Various combinations of dependency and polymorphism have been

neg: Cocoa butter at room temperature but readily melts once inside the mouth. Cocoa butter displays polymorphism, having different crystalline forms with different melting points. Conventionally the assignment of cocoa butter crystalline forms uses the nomenclature of Wille and Lutton with forms I, II, III, IV, V and VI having melting points 17.3, 23.3, 25.5, 27.5, 33.8 and 36.3 °C respectively. The production of chocolate aims to crystallise the chocolate so that the cocoa butter is predominantly in form V, which is the most stable form that can be obtained from melted cocoa butter. (Form VI either develops in solid cocoa butter after

neg: Polymorphism (materials science) obtained in the space group "Pca"2 when the compound was crystallised in the presence of an additive, trisindane. This experiment shows that additives can induce the appearance of polymorphic forms. Walter McCrone has stated that "every compound has different polymorphic forms, and that, in general, the number of forms known for a given compound is proportional to the time and money spent in research on that compound." Ostwald's rule or Ostwald's step rule, conceived by Wilhelm Ostwald, states that in general it is not the most stable but the least stable polymorph that crystallises first. See for examples the aforementioned

neg: Silicon forms. The polymorphism of SiC is characterized by a large family of similar crystalline structures called polytypes. They are variations of the same chemical compound that are identical in two dimensions and differ in the third. Thus they can be viewed as layers stacked in a certain sequence. It is made industrially by reduction of quartz sand with excess coke or anthracite at 2000–2500 °C in an electric furnace: It is the most thermally stable binary silicon compound, only decomposing through loss of silicon starting from around 2700 °C. It is resistant to most aqueous acids, phosphoric acid being an

neg: Zinc sulfide Zinc sulfide Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics. ZnS exists in two main crystalline forms, and this dualism is often a salient example of polymorphism. In each

neg: Silicon carbide to the CVD process, the pyrolysis method is advantageous because the polymer can be formed into various shapes prior to thermalization into the ceramic. Silicon carbide exists in about 250 crystalline forms. The polymorphism of SiC is characterized by a large family of similar crystalline structures called polytypes. They are variations of the same chemical compound that are identical in two dimensions and differ in the third. Thus, they can be viewed as layers stacked in a certain sequence. Alpha silicon carbide (α-SiC) is the most commonly encountered polymorph. It's formed at temperatures greater than 1700 °C and has a

neg: Allotropy ellipsoidal formations). The term "allotropy" is used for elements only, not for compounds. The more general term, used for any crystalline material, is polymorphism. Allotropy refers only to different forms of an element within the same phase (i.e.: solid, liquid or gas states); differences in these states alone would not constitute examples of allotropy. For some elements, allotropes have different molecular formulae despite difference in phase; for example, two allotropes of oxygen (dioxygen, O, and ozone, O) can both exist in the solid, liquid and gaseous states. Conversely, some elements do not maintain distinct allotropes in different phases; for example,

neg: Coregonus lavaretus is mostly of post-glacial origin. The resource polymorphism represented by the feeding morphs has evolved repeatedly and independently within individual lakes, and similar morphs in different lakes are not related to each other. There is much variation among the European whitefish forms, but in general they have a tapered body, a slightly protruding upper jaw and a fleshy dorsal fin that is typical of the salmon family. The snout is short and tapered, a fact that distinguishes this species from the two other North European "Coregonus" species, vendace ("Coregonus albula") and the introduced peled ("Coregonus peled"). The former has a

neg: Quantitative comparative linguistics also be semantic shifts and polymorphism. Analysis can be carried out on the "characters" of languages or on the "distances" of the languages. In the former case the input to a language classification generally takes the form of a data matrix where the rows correspond to the various languages being analysed and the columns correspond to different features or characters by which each language may be described. These features are of two types cognates or typological data. Characters can take one or more forms (homoplasy) and can be lexical, morphological or phonological. Cognates are morphemes (lexical or grammatical) or larger

neg: TAS2R38 variation in PTC tasting ability: people possessing two copies of the PAV polymorphism report PTC to be more bitter than "TAS2R38" heterozygotes, and people possessing two copies of the AVI/AVI polymorphism often report PTC as being essentially tasteless. These polymorphisms are hypothesized to affect taste by altering G-protein-binding domains. Because bitter substances are usually toxic, the presence of a “nontaster” geno- and phenotype seems evolutionarily undesirable. Several studies have suggested, however, that the AVI polymorphism may code for an entirely new receptor which processes a different and as-yet undiscovered bitter compound. Furthermore, the presence of the nontaster allele may reflect

neg: Walliserops a large adornment (probably multiple times as the trilobite shed its skin) its function was clearly important. Although a number of suggestions have been made (e.g. sensory apparatus, disguise or protection), the most satisfactory current explanation is that the trident served as "horns" similar to those of present day beetles such as the rhinoceros beetles. Sexual dimorphism was an intriguing prospect (longer trident forms as jousting males) when only two species (or possible dimorphs) were known. With the description of three species from the same location, polymorphism (e.g. caste system in ants and bees) was another prospect but seemed unlikely.

neg: Ruff determined by a simple genetic polymorphism. Territorial behaviour and appearance is recessive to satellite behaviour and appearance, while preliminary research results suggest that the faeder characteristics are genetically controlled by a single dominant gene. It was originally thought that the difference between territorial and satellite males was due to a sex-linked genetic factor, but in fact the genetic locus relevant for the mating strategy is located on an autosome, or non-sex chromosome. That means that both sexes can carry the two different forms of the gene, not just males. The female does not normally show evidence of her genetic type,

neg: Hindley–Milner type system polymorphic lambda calculus is not decidable. Instead, HM provides a "let-polymorphism" of the form restricting the binding mechanism in an extension of the expression syntax. Only values bound in a let construct are subject to instantiation, i.e. are polymorphic, while the parameters in lambda-abstractions are treated as being monomorphic. The remainder of the article is more technical as it has to present the HM method as it is handled in the literature. It proceeds as follows: The same description of the deduction system is used throughout, even for the two algorithms, to make the various forms in which the HM

neg: Polymorphism in Lepidoptera a diurnal moth occurs in continental Europe, western Asia and southern England, three forms occur in England: the typical homozygote; the rare homozygote ("bimacula") and the heterozygote ("medionigra"). It was studied there by E. B. Ford, and later by P. M. Sheppard and their co-workers over many years. Data is available from 1939 to the present day, got by the usual field method of capture-mark-release-recapture and by genetic analysis from breeding in captivity. The records cover gene frequency and population size for much of the twentieth century. In this instance the genetics appears to be simple: two alleles at a

neg: Earias insulana by low temperatures. Earias insulana The Egyptian stemborer, Egyptian bollworm, spiny bollworm or cotton spotted bollworm ("Earias insulana") is a moth of the Nolidae family. It is found in most of Africa, southern Europe, the Near East and Middle East, Japan, Taiwan, the Philippines, Australia and Hawaii. It is a rare in immigrant in Great Britain. The wingspan is 20–22 mm. Adults show strong seasonal polymorphism, depending on the temperature. Two distinct forms are present in some areas: a bright green summer form and a brownish-yellow autumn form. The larvae feed on okra, cotton and hibiscus, but have also been

neg: Earias insulana Earias insulana The Egyptian stemborer, Egyptian bollworm, spiny bollworm or cotton spotted bollworm ("Earias insulana") is a moth of the Nolidae family. It is found in most of Africa, southern Europe, the Near East and Middle East, Japan, Taiwan, the Philippines, Australia and Hawaii. It is a rare in immigrant in Great Britain. The wingspan is 20–22 mm. Adults show strong seasonal polymorphism, depending on the temperature. Two distinct forms are present in some areas: a bright green summer form and a brownish-yellow autumn form. The larvae feed on okra, cotton and hibiscus, but have also been recorded on rice,

neg: L-isoaspartyl methyltransferase been found to stimulate PIMT activity. The enzyme is present in human cytosol in two forms due to alternative splicing and differs among individuals in the population due to a single polymorphism at protein 119, either valine or isoleucine. The enzyme structure is described as a “doubly wound alpha/beta/alpha sandwich structure” which is quite consistent in all species analyzed thus far. If there is any difference in the sequences between different organisms it occurs in the regions connecting the three motifs in the sandwich structure, but the sequence of the individual motifs tends to be highly conserved. Researchers have found

neg: Polymorphism (materials science) a pyridinium salt. The review also questioned whether the polymorphs offered any advantages to the existing drug: something clearly demanded in a new patent. Acetylsalicylic acid has an elusive second polymorph that was first discovered by Vishweshwar et al.; fine structural details were given by Bond et al. A new crystal type was found after attempted co-crystallization of aspirin and levetiracetam from hot acetonitrile. In form I, two aspirin molecules form centrosymmetric dimers through the acetyl groups with the (acidic) methyl proton to carbonyl hydrogen bonds, and, in form II, each aspirin molecule forms the same hydrogen bonds, but then

neg: Crystal engineering the polymorphism. In organic molecules, three types of polymorphism are mainly observed. Packing polymorphism arises when molecules pack in different ways to give different structures. Conformational polymorphism, on the other hand is mostly seen in flexible molecules where molecules have multiple conformational possibilities within a small energy window. As a result, multiple crystal structures can be obtained with the same molecule but in different conformations. The rarest form of polymorphism arises from the differences in the primary synthon and this type of polymorphism is called as synthon polymorphism. With the growth in research in the cocrystals in recent times, it

neg: Polymorphism (materials science) Polymorphism (materials science) In materials science, polymorphism is the ability of a solid material to exist in more than one form or crystal structure. Polymorphism can potentially be found in any crystalline material including polymers, minerals, and metals, and is related to allotropy, which refers to chemical elements. The complete morphology of a material is described by polymorphism and other variables such as crystal habit, amorphous fraction or crystallographic defects. Polymorphism is relevant to the fields of pharmaceuticals, agrochemicals, pigments, dyestuffs, foods, and explosives. When polymorphism exists as a result of a difference in crystal packing, it is called packing

neg: Polymorphism (biology) there is no direct evidence of reproductive subdivision in the population". In 1999 Peter Grant agreed that "sympatric speciation [in this example] is unlikely to occur". If the population is panmixic, then "Geospiza conirostris" exhibits a balanced genetic polymorphism and not, as originally supposed, a case of nascent sympatric speciation. The selection maintaining the polymorphism maximises the species' niche by expanding its feeding opportunity. The genetics of this situation cannot be clarified in the absence of a detailed breeding program, but two loci with linkage disequilibrium is a possibility. Another interesting dimorphism is for the bills of young finches, which

neg: Gene polymorphism such as single strand conformation polymorphism analysis. A polymorphism can be any sequence difference. Examples include: Polymorphisms have been discovered in multiple XPD exons. XPD refers to ‘’’xeroderma pigmentosum group D’’’ and is involved in a DNA repair mechanism used during DNA replication. XPD works by cutting and removing segments of DNA that have been damaged due to things such as cigarette smoking and inhalation of other environmental carcinogens. Asp312Asn and Lys751Gln are the two common polymorphisms of XPD that result in a change in a single amino acid. This variation in Asn and Gln alleles is has been related

neg: Mutationism argued. Johanssen published his work in Danish in a 1903 paper "Om arvelighed i samfund og i rene linier" (On inheritance in populations and in pure lines), and in his 1905 book "Arvelighedslærens Elementer" (The Elements of Heredity). In 1915, Reginald Punnett argued in his book "Mimicry in Butterflies" that the 3 morphs (forms) of the butterfly "Papilio polytes", which mimic different host species of butterfly, demonstrated discontinuous evolution in action. The different forms existed in a stable polymorphism controlled by 2 Mendelian factors (genes). The alleles of these genes were certainly discontinuous, so Punnett supposed that they must have

neg: Caulerpa racemosa vitamin B1 while also being low in fat. Caulerpa racemosa Caulerpa racemosa is a species of edible green alga, a seaweed in the family Caulerpaceae. It is commonly known as sea grapes (along with the related "Caulerpa lentillifera") and is found in many areas of shallow sea around the world. There are a number of different forms and varieties, and one that appeared in the Mediterranean Sea in 1990, which is giving cause for concern as an invasive species. There are about 75 species of "Caulerpa". Many of them exhibit polymorphism, showing different growth forms in different habitats which makes

neg: Caulerpa racemosa Caulerpa racemosa Caulerpa racemosa is a species of edible green alga, a seaweed in the family Caulerpaceae. It is commonly known as sea grapes (along with the related "Caulerpa lentillifera") and is found in many areas of shallow sea around the world. There are a number of different forms and varieties, and one that appeared in the Mediterranean Sea in 1990, which is giving cause for concern as an invasive species. There are about 75 species of "Caulerpa". Many of them exhibit polymorphism, showing different growth forms in different habitats which makes them difficult to identify. "Caulerpa racemosa", "C. laetevirens"

neg: Plumage aberration (e.g., all normally black plumage becoming grey). In some birds – many true owls (Strigidae), some nightjars (Caprimulgidae) and a few cuckoos ("Cuculus" and relatives) being widely known examples – there is colour polymorphism. This means that two or more colour variants are numerous within their populations during all or at least most seasons and plumages; in the above-mentioned examples a brown (phaeomelanin) and grey (eumelanin) morph exist, termed "hepatic form" particularly in the cuckoos. Other cases of natural polymorphism are of various kinds; many are melanic/nonmelanic (some paradise-flycatchers, "Terpsiphone", for example), but more unusual types of polymorphism exist

neg: Zoothamnium a single unit in a zig zag fashion. The protozoa can display polymorphism, or multiple physical forms of the same cell. Those on the stalks are shaped like rods, but those in the region of the ciliated oral apparatus of the zooids are shaped like small spheres. Three different forms of the individual ciliate cells are present at the ends of the stalk, which are distinct in both morphology and function: Initial colonization is established by swarmer cells. Once a somatic girdle or circular rows of cilia are developed, a mature macrozooid can leave the mother colony as a swarmer.