What does polymorphic mean in biology

what does polymorphic mean in biology

Genetic Polymorphism—Different Does Not Mean Mutated

polymorphic - relating to the occurrence of more than one kind of individual (independent of sexual differences) in an interbreeding population; "a polymorphic species" polymorphous biological science, biology - the science that studies living organisms. Polymorphic definition, (of a species) having more than one form or type as a result of discontinuous variation: Cabbage, kale, broccoli, and cauliflower are all forms of a .

Polymorphismin biologya discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single dos. A discontinuous genetic variation divides the individuals of a population polmyorphic two or more sharply distinct forms. The most obvious example of this is the separation of most higher organisms into male and female sexes.

Another example is the different blood types in humans. In continuous variation, by contrast, the individuals do not fall into sharp classes but instead are almost imperceptibly graded between wide extremes. Examples include the smooth graduation of height among individuals of human populations and the graduations possible between the different geographic races. If popymorphic frequency of two or more discontinuous forms within a species is too high to be explained by mutationthe variation—as well as the population displaying it—is said to be polymorphic.

A polymorphism that persists over many generations is usually maintained because no one form possesses an overall advantage or disadvantage over the others in terms of natural selection. Some polymorphisms have no visible manifestations and require biochemical techniques to identify the differences that occur between the chromosomes, proteins, or DNA of different forms.

The castes that occur in social insects are a special form of polymorphism that is attributable to differences in nutrition rather than to genetic variations.

Additional Info. More About Contributors Article History. Print Cite verified Cite. While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.

Facebook Twitter. Give Feedback External Websites. Let us know if you have suggestions to improve this article requires login. External Websites. Oplymorphic LibreTexts - Polymorphisms. Articles from Britannica Encyclopedias for elementary and high school students. The Editors of Encyclopaedia Britannica Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree See Article History.

Alternative Titles: genetic polymorphism, how to sell art online in india variation. Read More on This Topic. Polymorphism is marked in several groups of Homoptera. The Cicadidae dose similar in form but vary in size and coloration Learn More in these related Britannica articles:.

The Cicadidae are similar in form but vary in size and coloration. The Cercopidae include different types, with the small Clastoptera being short, man, and froglike in appearance and called froghoppers and the Philaenus being more….

Three populations bio,ogy colour variants morphs are found in the lagoon of Venice; they are known as violacea homozygous genotype Mea V V Polgmorphicmaculata homozygous genotype V M V …. Another strategy is genetic polymorphism, the selection of a diversified gene pool that yields different genotypes, each adapted to a specific subenvironment.

History at your fingertips. Sign up here to see what happened On This Dayevery day in your inbox! Email address. By polymorpic up, you agree to our Privacy Notice. Be in what year was the first steam train invented the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox.

pol·y·mor·phism

Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph. In order to be classified as such, morphs must occupy the same habitat at the same time and belong to a panmictic population. Polymorphism, in biology, a discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. The most obvious example of this is the separation of most higher organisms into male and female sexes. polymorphism. the presence in a population of two or more MORPHS, produced when different alleles of a gene occur in the same population and the rarest allele is not maintained merely by repeated MUTATION (i.e. has a frequency higher than, say, %). Such a definition excludes continuously variable characters such as height or skin colour in humans, but the human blood groups .

Polymorphism involves one of two or more variants of a particular DNA sequence. The most common type of polymorphism involves variation at a single base pair. Polymorphisms can also be much larger in size and involve long stretches of DNA.

Called a single nucleotide polymorphism, or SNP pronounced snip , scientists are studying how SNPs in the human genome correlate with disease, drug response, and other phenotypes. Polymorphism, by strict definitions which hardly anybody pays attention to anymore, is a place in the DNA sequence where there is variation, and the less common variant is present in at least one percent of the people of who you test.

That is to distinguish, therefore, polymorphism from a rare variant that might occur in only one in 1, people. A polymorphism, it has to occur in at least one in people. Polymorphisms could be not just single-letter changes like a C instead of T. They could also be something more elaborate, like a whole stretch of DNA, that is either present or absent.

You might call that a copy number variant; those are all polymorphisms. But this is basically a general term to talk about diversity in genomes in a species. Francis S. Collins, M. Featured Content. Introduction to Genomics. Polygenic Risk Scores.

4 thoughts on “What does polymorphic mean in biology

Add a comment

Your email will not be published. Required fields are marked *