linkage group

linkage group
a group of genes in a chromosome that tends to be inherited as a unit.
[1935-40]

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All the genes on a single chromosome.

They are inherited as a group; during cell division they act and move as a unit rather than independently. Variations in linkage groups can occur if a chromosome breaks, and the sections join with the partner chromosome if it has broken in the same places. This exchange of genes between chromosomes, called crossing-over, usually occurs during meiosis. Sex linkage is the tendency of a characteristic to be linked to one sex; sex-linked traits in humans include red-green colour blindness and hemophilia.

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      in genetics, all of the genes on a single chromosome. They are inherited as a group; that is, during cell division they act and move as a unit rather than independently. The existence of linkage groups is the reason some traits do not comply with Mendel's law of independent assortment (recombination of genes and the traits they control); i.e., the principle applies only if genes are located on different chromosomes. Variation in the gene composition of a chromosome can occur when a chromosome breaks, and the sections join with the partner chromosome if it has broken in the same places. This exchange of genes between chromosomes, called crossing over, usually occurs during meiosis, when the total number of chromosomes is halved.

      Sex linkage is the tendency of a characteristic to be linked to one sex. The X chromosome in Drosophila flies and human beings, for example, carries a complete set of genes; the Y chromosome has only a few genes. Eggs of females carry an X chromosome; sperm of males may carry an X or a Y. An egg fertilized by a sperm with an X chromosome results in a female; one fertilized by a sperm with a Y chromosome results in a male. In offspring with the XY chromosome pair, any trait carried by the X chromosome will appear unless there is a corresponding gene (allele) on the Y chromosome. Examples of sex-linked traits in man are red–green colour blindness and hemophilia. These traits are controlled by genes on the X chromosome and thus occur much more frequently in men than in women because there is no allele on the Y chromosome to offset them. See also sex chromosome.

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Universalium. 2010.

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Look at other dictionaries:

  • linkage group — linkage group. См. группа сцепления. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • linkage group — n a set of genes at different loci on the same chromosome that except for crossing over tend to act as a single pair of genes in meiosis instead of undergoing independent assortment …   Medical dictionary

  • linkage group — noun any pair of genes that tend to be transmitted together the genes of Drosophila fall into four linkage groups • Syn: ↑linked genes • Hypernyms: ↑gene, ↑cistron, ↑factor * * * noun : a group of genes that tend to be i …   Useful english dictionary

  • linkage group — sankibos grupė statusas T sritis augalininkystė apibrėžtis Vienos chromosomos genų visuma. atitikmenys: angl. linkage group rus. группа cцепления …   Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

  • linkage group — A group of gene loci placed in a linear order on a chromosome …   Dictionary of invertebrate zoology

  • linkage group — /ˈlɪŋkɪdʒ grup/ (say lingkij groohp) noun a group of genes in one chromosome that tend to be inherited as an inseparable unit …  

  • linkage group — noun Date: 1921 a set of linked genes at different loci on the same chromosome …   New Collegiate Dictionary

  • linkage group —    The genes located on a single chromosome …   Forensic science glossary

  • circular linkage group — circular linkage group. См. кольцевая группа сцепления. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • linkage — [liŋk′ij] n. 1. a linking or being linked 2. a series or system of links, slides, cranks, wheels, or gears for transmitting power or motion 3. Biol. the tendency of some genes to remain together and act as a unit (linkage group) in inheritance,… …   English World dictionary

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