A Bacterium with the Genotype Met⁺his⁺lys^-arg⁺ Has Been Transformed with DNA

question 19

Essay

A bacterium with the genotype met⁺his⁺lys^-arg⁺ has been transformed with DNA from a second bacterium that has the genotype met⁺his^-lys⁺arg^-.
Following the transformation,scientists streaked a sample of a transformed bacterium onto several different plates that contain different nutritional supplements in order to determine the transformant's genotype.Using the results of the experiments (shown below),determine what crossovers occurred to produce the bacterium.On the above diagram,draw the crossovers that are necessary to produce a bacterium that fits the observed growth profile.