Horizontal gene transfer in bacteria Which process specifically transports bacterial DNA from one bacterium to another by means of bacteriophages (virus-mediated transfer)?

Introduction / Context:Bacteria exchange genetic information by several horizontal gene transfer mechanisms. Distinguishing conjugation, transformation, and transduction is essential in microbiology, antimicrobial resistance studies, and biotechnology. This question asks which process uses bacteriophages (bacterial viruses) to shuttle DNA between cells.

Given Data / Assumptions:

• Bacteriophages infect bacteria and can package DNA.
• The focus is on the mechanism that uses phage particles as vehicles for DNA transfer.
• Standard definitions of conjugation, transformation, and translation are assumed.

Concept / Approach:

Transduction = phage-mediated DNA transfer.Conjugation = cell-to-cell contact via pilus and plasmid or chromosomal DNA transfer.Transformation = uptake of naked DNA from the environment.Translation = protein synthesis from mRNA (not a gene transfer method).Transduction occurs as generalized transduction (random host fragments packaged, e.g., P1, P22) or specialized transduction (specific adjacent genes transferred after prophage excision errors, e.g., lambda).

Step-by-Step Solution:

Verification / Alternative check:

Classic experiments with phage P22 in Salmonella and P1 in E. coli demonstrate donor DNA markers moving to recipients within phage heads, independent of physical contact, confirming transduction as the correct mechanism.

Why Other Options Are Wrong:

• Conjugation: Requires conjugative pilus and direct contact.
• Transformation: DNA uptake from the environment; no phage vehicle.
• Translation: Central dogma step; unrelated to gene transfer.
• None of the above: Incorrect because transduction exists and is well characterized.

Common Pitfalls:

• Confusing “transduction” with “translation” due to similar spelling.
• Assuming all gene transfer requires cell contact; phage-mediated transfer does not.

Final Answer:

Transduction