Chapter 7, Problem 8EQ

An Hfr strain that is $his{E}^{+}$ and $phe{A}^{+}$ was mixed with a strain that is $his{E}^{-}$ and $phe{A}^{-}.$ The conjugation was interrupted and the percentage of recombinants for each gene was determined by streaking on a medium that lacked either histidine or phenylalanine. The following results were obtained:

Duration of conjugation (minutes)

A. Determine the map distance (in minutes) between these two genes.

B. In a previous experiment, it was found that $hisE$ is 4 minutes away from $pabB.$ The gene $pheA$ was shown to be 17 minutes from $pabB.$ Draw a genetic map describing the locations of all three genes.