Calculating a recombination frequency allows molecular geneticists to construct a gene map, which shows the layout of chromosomes in terms of the relative positions of the genes they include.

In linkage maps, you may see distances expressed as centimorgans or map units rather than recombination frequencies. If recombination frequency is equal to distance in map units, what is the approximate distance between genes A and B? Test your knowledge on recombination frequency and gene mapping! If you're seeing this message, it means we're having trouble loading external resources on our website. The distance between the genes can be written as a percentage or as a MAP UNIT. Recombination occurs in meiosis in crossing over and throws off the predicted phenotype values. Luckily, there's a direct relationship among these values: a 1 % 1\% 1 % 1, percent recombination frequency is equivalent to 1 1 1 1 centimorgan or 1 1 1 1 map unit. This map shows chromosome #2 of Drosophila melanogaster.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. The gene for body color and and wing size are 17 map units apart. Sample Problem: Given the crossover frequency of each of the genes on the chart, construct a chromosome map. 3 map units Use the following information to answer the question.