How would you solve this problem The correct answer is in re

How would you solve this problem? The correct answer is in red.

Consider the cross: Hfr: neo^S pro + met + gal-man + lys- x F^-: neo^R pro - met - gal + man - lys + where the genetic map is shown below (the

Solution

Answer

The Hfr strains have a certain F factor incorporated into the bacterial sites in different orientations. The DNA transfer is initiated at the origin of transfer (Ori T) with the F factor. During conjugation, the Hfr is able to pull all the positive genes into F^-. Since, strains are plated on a specific media, they require minimal media, the antibiotics F- is resistant to but Hfr is sensitive to and the remaining genes necessary for the growth. The recipient F- will never receive the complete F factor sequence; they will not become F⁺

According to the genetic map of both Hfr and F-, the neomycin sensitive and resistance part is located on other part from other genes which are pro, met, man, and lysine. After conjugation, the resistance part will be present while the other genes are replaced by the Hfr genes. Thus, we should select a minimal media containing neomycin, mannose methionine, lysine, and proline.