The phage P1 is used as a generalized transducing phage in an experiment combining a donor strain of E. coli of genotype leu⁺ phe⁺ ala⁺ and a recipient strain that is leu⁻ phe⁻ ala⁻. In separate experiments, transductants are selected for leu⁺ (Experiment A), for ala⁺ (Experiment B), and for phe⁺ (Experiment C). Following selection, transductant genotypes for the unselected markers are identified. The selection experiment results below show the frequency of each genotype.Experiment A Experiment B Experiment Cphe⁻ ala⁻ 26% leu⁻ ala⁻ 65% leu⁻ phe⁻ 71%phe⁺ ala⁻ 50% leu⁺ ala⁻. 48% leu⁺ phe⁻ 21%phe⁻ ala⁺ 19% leu⁻ ala⁺ 0% leu⁻ phe⁺ 0%phe⁺ ala⁺ 3% leu⁺ ala⁺ 4% leu⁺ phe⁺ 3%Diagram the crossover events that form each of the transductants in Experiment A.

How is the frequency of cotransduction related to the relative positions of genes on a bacterial chromosome? Draw a map of three genes and describe the expected relationship of cotransduction frequencies to the map.

A triple-auxotrophic strain of E. coli having the genotype phe⁻ met⁻ ara⁻ is used as a recipient strain in a transduction experiment. The strain is unable to synthesize its own phenylalanine or methionine, and it carries a mutation that leaves it unable to utilize the sugar arabinose for growth. The recipient is crossed to a prototrophic strain with the genotype phe⁺ met⁺ ara⁺. The table below shows the selected marker and gives cotransduction frequencies for the unselected markers.Selected Selected Colonies Containing the Marker Unselected Marker (%) _phe⁺ met⁺ ara⁺met⁺ 4 - 7phe⁺ - 2 51met⁺, phe⁺. - - 79ara⁺ 68 5 -Use the cotransduction data to determine the order of these genes.

A triple-auxotrophic strain of E. coli having the genotype phe⁻ met⁻ ara⁻ is used as a recipient strain in a transduction experiment. The strain is unable to synthesize its own phenylalanine or methionine, and it carries a mutation that leaves it unable to utilize the sugar arabinose for growth. The recipient is crossed to a prototrophic strain with the genotype phe⁺ met⁺ ara⁺. The table below shows the selected marker and gives cotransduction frequencies for the unselected markers.Selected Selected Colonies Containing the Marker Unselected Marker (%) _phe⁺ met⁺ ara⁺met⁺ 4 - 7phe⁺ - 2 51met⁺, phe⁺. - - 79ara⁺ 68 5 -Identify the compounds present in each of the selective media.

The phage P1 is used as a generalized transducing phage in an experiment combining a donor strain of E. coli of genotype leu⁺ phe⁺ ala⁺ and a recipient strain that is leu⁻ phe⁻ ala⁻. In separate experiments, transductants are selected for leu⁺ (Experiment A), for ala⁺ (Experiment B), and for phe⁺ (Experiment C). Following selection, transductant genotypes for the unselected markers are identified. The selection experiment results below show the frequency of each genotype.Experiment A Experiment B Experiment Cphe⁻ ala⁻ 26% leu⁻ ala⁻ 65% leu⁻ phe⁻ 71%phe⁺ ala⁻ 50% leu⁺ ala⁻. 48% leu⁺ phe⁻ 21%phe⁻ ala⁺ 19% leu⁻ ala⁺ 0% leu⁻ phe⁺ 0%phe⁺ ala⁺ 3% leu⁺ ala⁺ 4% leu⁺ phe⁺ 3%In Experiment B, why are there no transductants with the genotype leu⁻ ala⁺?

The phage P1 is used as a generalized transducing phage in an experiment combining a donor strain of E. coli of genotype leu⁺ phe⁺ ala⁺ and a recipient strain that is leu⁻ phe⁻ ala⁻. In separate experiments, transductants are selected for leu⁺ (Experiment A), for ala⁺ (Experiment B), and for phe⁺ (Experiment C). Following selection, transductant genotypes for the unselected markers are identified. The selection experiment results below show the frequency of each genotype.Experiment A Experiment B Experiment Cphe⁻ ala⁻ 26% leu⁻ ala⁻ 65% leu⁻ phe⁻ 71%phe⁺ ala⁻ 50% leu⁺ ala⁻. 48% leu⁺ phe⁻ 21%phe⁻ ala⁺ 19% leu⁻ ala⁺ 0% leu⁻ phe⁺ 0%phe⁺ ala⁺ 3% leu⁺ ala⁺ 4% leu⁺ phe⁺ 3%Determine the order of genes on the donor chromosome.

The phage P1 is used as a generalized transducing phage in an experiment combining a donor strain of E. coli of genotype leu⁺ phe⁺ ala⁺ and a recipient strain that is leu⁻ phe⁻ ala⁻. In separate experiments, transductants are selected for leu⁺ (Experiment A), for ala⁺ (Experiment B), and for phe⁺ (Experiment C). Following selection, transductant genotypes for the unselected markers are identified. The selection experiment results below show the frequency of each genotype.Experiment A Experiment B Experiment Cphe⁻ ala⁻ 26% leu⁻ ala⁻ 65% leu⁻ phe⁻ 71%phe⁺ ala⁻ 50% leu⁺ ala⁻. 48% leu⁺ phe⁻ 21%phe⁻ ala⁺ 19% leu⁻ ala⁺ 0% leu⁻ phe⁺ 0%phe⁺ ala⁺ 3% leu⁺ ala⁺ 4% leu⁺ phe⁺ 3%What compound or compounds are added to the minimal medium to select for transductants in Experiments A, B, and C?