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Article: Linkage and Gene Mapping
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- Biology
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Linkage and Gene Mapping
Linkage refers to the presence of two different genes on the same
chromosome
. Two genes that occur on the same chromosome are said to be linked, and those that occur very close together are tightly linked. Study of linkage provides information about the relative position of genes on chromosomes, allowing the construction of chromosome maps.
Basic Concepts
Different forms of the same gene, called
alleles
, are present on matching, or homologous, chromosomes in similar positions, or loci. For instance, in Gregor Mendel's experiments with peas, green and yellow are two alleles for pod color. In a heterozygote, which has both alleles, the two alleles occupy ...