Search results
Results from the WOW.Com Content Network
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 .
In biology, polymorphism [1] 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).
[10] The alternative model - the selfing avoidance model - was introduced by Charlesworth and Charlesworth in 1979 using a population genetic approach. The selfing avoidance model assumes that the self-incompatibility system was the first trait to evolve and that the physical attribute of reciprocal herkogamy evolved as a response to the former.
A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 [ 3 ] and then again in his 1982 book The Extended Phenotype suggested that one can regard bird nests and other built structures such as ...
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 ...
Polymorphisms can be identified in the laboratory using a variety of methods. Many methods employ PCR to amplify the sequence of a gene. Once amplified, polymorphisms and mutations in the sequence can be detected by DNA sequencing, either directly or after screening for variation with a method such as single strand conformation polymorphism analysis.
Pages in category "Polymorphism (biology)" The following 17 pages are in this category, out of 17 total. This list may not reflect recent changes. ...
In a classic study on the ebony mutation, Kalmus demonstrated how polymorphism can persist in a population through heterozygote advantage. [10] If weakness were the only effect of the mutant allele, so it conveyed only disadvantages, natural selection would weed out this version of the gene until it became extinct from the population.