Question

Using recombination frequency to map genes relative to each other is a powerful tool in genetics. A major limitation, however, is that Genetic Distance has an upper limit (i.e. one cannot establish linkage for genes that are more than 50 cM distant). Please discuss/describe this limitation. Why is there a limit? What does it mean? Use both words and diagrams in your answer.

Answer 1

There is a limit because they are assorted independently, and random assortment of genes could only generate a 50% of recombination. Genes that are assorted independently produce 1:1 parental to non-parental (parental means that it is the same as the father, and non parental means that it is gene combination different from the parents). So, the recombination frequency is obtain non parental/ total= 1/1+1=50%. Remembering that the recombination frequency between two genes is the proportion of offspring in which a recombination event ocurred between these two genes during meiosis. So the probability that it would be parental and non parental is 50% as calculated before.