linkage

Examples of linkage in the following topics:

• Genetic Linkage and Violation of the Law of Independent Assortment

  • The segregation of alleles into gametes can be influenced by linkage, in which genes that are located physically close to each other on the same chromosome are more likely to be inherited as a pair.
  • To understand this, let's consider the biological basis of gene linkage and recombination.
  • Mendel's seminal publication makes no mention of linkage, and many researchers have questioned whether he encountered linkage, but chose not to publish those crosses out of concern that they would invalidate his independent assortment postulate.
  • However, even if the genes he examined were not located on separate chromosomes, it is possible that he simply did not observe linkage because of the extensive shuffling effects of recombination.

• Lambda sets and bridges

  • This approach identifies the #2 to #5 (MAYR to COMM) linkage as the most important one in the graph - in the sense that it carries a great deal of traffic, and the graph would be most disrupted if it were removed.
  • This result can be confirmed by looking at the graph, where we see that most actors are connected to most other actors by way of the linkage between #2 and #5.
  • Considerably less critical are linkages between 2 and 5 and actors 1, 3, 4, 7, and 10.

• Adherens Junctions

  • Adherens junctions provide strong mechanical attachments between adjacent cells through linkage of cytoplasmic face with cytoskeleton.

• Mechanisms of Chemical Digestion

  • Amylose is not highly branched and consists mainly of long chains of glucose linked by α1:4 linkages.
  • Cellulose, the most abundant starch in nature, is formed of β1:4 linkages and cannot be digested in humans, although bacterial action in the colon does breakdown a minute amount.
  • Glycogen is a multi-branched starch with linkages at the 1:4 and 1:6 position.
  • This breaks amylose down into mainly disaccharides, and glycogen with its 1:6 linkages into polysaccharides .

• DNA and RNA

  • The phosphate residue is attached to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′3′ phosphodiester linkage.
  • The phosphodiester linkage is not formed by simple dehydration reaction like the other linkages connecting monomers in macromolecules: its formation involves the removal of two phosphate groups.
  • A polynucleotide may have thousands of such phosphodiester linkages.

• Genetic Maps

  • The study of genetic maps begins with linkage analysis, a procedure that analyzes the recombination frequency between genes to determine if they are linked or show independent assortment.
  • The term linkage was used before the discovery of DNA.
  • The mapping of genes relative to each other based on linkage analysis led to the development of the first genetic maps.
  • Linkage analysis involves studying the recombination frequency between any two genes.

• Intorduction to qualitative analysis

  • We will examine two models that ask meaningful (alternative) questions about the patterns of linkage between actors and events.

• Carbohydrate Molecules

  • Glycosidic bonds (also called glycosidic linkages) can be of the alpha or the beta type.
  • In sucrose, a glycosidic linkage is formed between carbon 1 in glucose and carbon 2 in fructose.
  • In cellulose, glucose monomers are linked in unbranched chains by β 1-4 glycosidic linkages.

• State and Local Party Organization

  • Linkage institutions provide a way for people to get involved in government and the political process.
  • They are not the only linkage institutions; others include blogs, non-partisan local governments, and school boards.

• Genetic Linkage and Distances