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 - 7 phe⁺ - 2 51 met⁺, phe⁺. - - 79 ara⁺ 68 5 - Identify the compounds present in each of the selective media.