During horizontal gene transfer, a bacteriophage accidentally packages a fragment of the donor bacterium's chromosomal DNA (not phage DNA) and injects it into a recipient bacterium. This process is called:

• A Specialised (restricted) transduction
• B Transformation
• C Conjugation
• D Generalised transduction ✓

Explanation

In generalised transduction, a lytic bacteriophage mistakenly packages any random fragment of host chromosomal DNA (instead of phage DNA) during assembly; upon infection of a new bacterium, this host DNA is injected and can integrate into the recipient's chromosome. Any chromosomal gene can theoretically be transferred. Specialised (restricted) transduction occurs with lysogenic phages (e.g., lambda phage) that integrate at a specific chromosomal site; only adjacent bacterial genes (e.g., gal or bio in lambda) are transduced. Transformation involves uptake of naked DNA; conjugation requires direct cell-to-cell contact via pilus.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.