Define transduction in bacterial genetics.

• A. Transduction is DNA transfer by bacteriophages.
• B. Transduction is uptake of naked DNA from the environment.
• C. Transduction is direct DNA transfer via pili.
• D. Transduction is conjugation via sex pili.

Answer: (A)

Transduction is the transfer of bacterial DNA from one cell to another by a bacteriophage. During phage infection, the phage can mistakenly package pieces of the donor's DNA into its head. When that phage goes on to infect a new bacterium, it injects that DNA, which can recombine into the recipient’s genome and create new genetic combinations. There are two forms: generalized transduction, where any donor gene can be carried, and specialized transduction, where only genes near the phage's integration site are transferred. This is distinct from transformation, which is uptake of naked DNA from the environment, and from conjugation, which requires direct cell-to-cell contact and transfer via pili.