... genotype a- d- e- are infected with transducing particles obtained following phage
infection of bacteria with the genotype a+ d+ e+. Using appropriate selection techniques, cells transduced for the a locus are identified and then tested further to determine how many of them have been transduced for one or both of the other loci. The genotypes of the transductants and their frequencies are as follows:
Genotype Frequency
a+d+e+ 160
a+d+e- 10
a+d-e+ 120
a+d-e- 820
A. Calculate the cotransduction frequency for a and d. (2 points)
B. Calculate the cotransduction frequency for a and e. (2 points)
C. Assume the average length of the transducing DNA (L) is 2.5 minutes and calculate the map distance (d) between the loci. (4 points)
D. Construct a linkage map showing the order of the genes and the distances between all loci.