Paper I — 2025 March (Supplementary) (2010 Scheme) — Q10
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Paper I
2025 March (Supplementary) (2010 Scheme) · 40 marks · 120 min
Question
Name two horizontal gene transfer method in bacteria
Q102 marksShort Notes
Answer
Two methods of horizontal gene transfer in bacteria:
Conjugation — direct cell-to-cell transfer of plasmid DNA (e.g., F plasmid, R plasmid) from a donor to a recipient bacterium via a sex pilus, forming a conjugation bridge through which DNA passes; the principal mechanism spreading multidrug-resistance (R) plasmids between bacteria.
Transduction — transfer of bacterial DNA via a bacteriophage acting as vector; generalized transduction occurs when a lytic phage mistakenly packages random host DNA; specialized transduction occurs when a temperate (lysogenic) phage carries adjacent bacterial genes on excision from its integrated site.
(A third valid example: transformation — direct uptake of free/naked DNA from the environment by a competent recipient bacterial cell.)
