polymorphism

Examples of polymorphism in the following topics:

• Crystalline Solids

  • Three polymorphs have been identified.
  • Seven years later a second polymorph of ranitidine was patented by the same company.
  • It displayed six polymorphic crystal forms, pictures of which are shown below.
  • It is the polymorphs of this matrix that influence the quality of chocolate.
  • Low melting polymorphs feel too sticky or thick in the mouth.

• MHC Polymorphism and Antigen Binding

  • The MHC genes are highly polymorphic; this means that there are many different alleles in the different individuals inside a population.
  • The polymorphism is so high that in a mixed population (non-endogamic) there are not two individuals with exactly the same set of MHC genes and molecules, with the exception of identical twins.
  • The polymorphic regions in each allele are located in the region for peptide contact, which is going to be displayed to the lymphocyte.
  • For this reason, the contact region for each allele of MHC molecule is highly variable, as the polymorphic residues of the MHC will create specific clefts in which only certain types of residues of the peptide can enter.
  • The variations in the MHC molecules (responsible for the polymorphism) are the result of the inheritance of different MHC molecules, and they are not induced by recombination, as it is the case for the antigen receptors.

• No Perfect Organism

  • Therefore, the process of evolution is limited by a population's existing genetic variance, the physical proximity of alleles, non-beneficial intermediate morphs in a polymorphic population, and non-adaptive evolutionary forces.
  • Furthermore, natural selection can be constrained by the relationships between different polymorphisms.
  • Color and pattern morphs of the grove snail, Cepaea nemoralis.The polymorphism, when two or more different genotypes exist within a given species, in grove snails seems to have several causes, including predation by thrushes.

• Class Scyphozoa

  • Scyphozoans are free-swimming, polymorphic, dioecious, and carnivorous cnidarians with a prominent medusa morphology.
  • The life cycle of these animals can be described as polymorphic because they exhibit both a medusal and polypoid body plan at some point .

• Aluminosilicates

  • The triple point of these three polymorphs is located at a temperature of 500 °C and a pressure of 0.4 GPa.
  • The phase diagram of Al2SiO5 showing its different forms (called "polymorphs").

• Political Leaders and Opinion Makers

  • Merton distinguishes two types of opinion leadership: monomorphic and polymorphic.
  • In contrast, polymorphic opinion leaders are able to influence others in a broad range of domains.
  • Variants of polymorphic opinion leadership include market mavenism, personality strength and generalized opinion leadership.

• Genetic Maps

  • In general, a good genetic marker is a region on the chromosome that shows variability or polymorphism (multiple forms) in the population.
  • Some genetic markers used in generating genetic maps are restriction fragment length polymorphisms (RFLP), variable number of tandem repeats (VNTRs), microsatellite polymorphisms, and the single nucleotide polymorphisms (SNPs).
  • Certain regions of the chromosome that are subject to polymorphism will lead to the generation of the unique banding pattern.
  • Microsatellite polymorphisms are similar to VNTRs, but the repeat unit is very small; thus, it is often referred to as short tandem repeats(STRs).

• Class Cubozoa and Class Hydrozoa

  • Cubozoans live as box-shaped medusae while Hydrozoans are true polymorphs and can be found as colonial or solitary organisms.
  • Animals in this class are polymorphs: most exhibit both polypoid and medusoid forms in their lifecycle, although this is variable.

• Properties of Sulfur

  • At 95.2 °C, below its melting temperature, cyclooctasulfur changes from α-octasulfur to the β-polymorph.

• T Cell Receptors

  • T lymphocytes have a dual specificity: they recognize polymorphic residues of self major histocompatibility complex (MHC) molecules, which accounts for their MHC restriction; they also recognize residues of peptide antigens displayed by these MHC molecules, which is responsible for their specificity.