F factor (fertility plasmid) function: F-factor plasmids primarily mediate which genetic process in bacteria?

Introduction / Context:
The F (fertility) plasmid is a classic element of bacterial genetics. It encodes the machinery that enables direct DNA transfer between cells. Recognizing its role is essential for understanding how traits spread in populations.

Given Data / Assumptions:

• F factors encode tra genes for pilus formation and DNA transfer.
• Conjugation requires cell-to-cell contact.
• The question asks for the primary genetic process mediated by F plasmids.

Concept / Approach:

Differentiate basic genetic processes: conjugation (DNA transfer via contact), transduction (phage-mediated), and transformation (DNA uptake). F plasmids specifically drive conjugative transfer, occasionally integrating into the chromosome (Hfr) to mobilize chromosomal genes.

Step-by-Step Solution:

Verification / Alternative check:

Hfr mapping experiments demonstrate F-mediated chromosomal gene transfer via conjugation, cementing its central role.

Why Other Options Are Wrong:

Replication/transcription occur in all cells and are not unique to F plasmids.

Transduction is phage-based and independent of F factor.

Common Pitfalls:

Confusing F with R plasmids; some R plasmids are conjugative, but “F” specifically refers to the fertility factor driving conjugation.

Final Answer:

Conjugation