Viruses are isolated from wild-type E.coli cells that have been infected with wild-type bacteriophage λ.These viruses are used to infect a Gal⁻ strain of E.coli.A few bacterial colonies that can grow on galactose are obtained, while no bacteria that can grow on galactose are obtained from cells that were not infected.What has happened? A)A λ gal⁺ phage was generated. B)Reversion mutations have occurred. C)The bacteria underwent conjugation with a Gal⁺ strain. D)The bacteria underwent transformation with a wild-type E.coli strain.

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The ability of the few bacterial colonies to grow on galactose after infection with bacteriophage λ, but not in uninfected cells, suggests that a specialized transduction event occurred. This is where the bacteriophage λ acquired the galactose-utilization genes from the wild-type E.coli and transferred these genes to the Gal⁻ strain, generating a λ gal⁺ phage. This process allows the recipient bacteria to gain the ability to metabolize galactose.

Viruses Are Isolated from Wild-Type E