Practice question

Incomplete linkage represents intermediate state where genes reside on same chromosome but distance sufficient for occasional crossover to separate alleles during meiosis. Meiosis produces majority parental chromatids plus minority recombinant chromatids yielding recombinant frequency between zero indicating absolute linkage and fifty percent indicating independent assortment. Value increases proportionally with physical separation providing molecular ruler for ordering loci along chromosome. Test cross directly quantifies this fraction assigning map distance in centimorgans proportional to recombination frequency with corrections for undetected double crossovers over larger intervals for accuracy.