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## Mapping of genes * Gene/chromosome maps assign a gene to a specific location on a chromosome called its locus (plural loci). This is important because knowing where the gene's location can be used to isolate its DNA and even to understand gene function. ## Analyzing the result of a three point c...

## Mapping of genes * Gene/chromosome maps assign a gene to a specific location on a chromosome called its locus (plural loci). This is important because knowing where the gene's location can be used to isolate its DNA and even to understand gene function. ## Analyzing the result of a three point cross * Testcross progeny have four sets of reciprocal pairs of genotypes. * Most frequent pair has Parental configuration of alleles. * Least frequent pairs result in from double crossovers. * Comparing pairwise RES of three genes show which are furthest apart and which of the three is in the middle. | | | | | |---|---|---|---| | 1779 | vg b Pr | Parental combination for all three genes | | 1654 | vg+ bt Pr | | | 252 | vg+ b Pr | Recombination for vg relative to parental combinations for b and Pr | | 241 | vg b Pr+ | | | 131 | vg+ b Pr | | | 118 | vg bt Pr | | | 13 | vg b Pr | | | a | vg bt Pr | | | Total | | |---|---| | 4197 | |