Practice question

For small intervals double crossovers rare so observed recombinant frequency directly estimates map distance because each recombinant chromosome reflects single crossover event between chromatids. Recombinant proportion times one hundred gives separation in centimorgans: twenty percent recombinant gametes observed in test cross equals twenty centimorgans between loci on linkage map. Relationship holds up to ten to fifteen centimorgans; beyond that undetected double exchanges cause underestimation requiring mapping functions to convert observed recombination to additive map length reflecting true chromatid exchange events and interference accurately.