Which method involves cell-to-cell contact and transfer of genetic material between bacteria?

Which method involves cell-to-cell contact and transfer of genetic material between bacteria?

• A. Conjugation
• B. Transformation
• C. Transduction
• D. Electroporation

Answer: (A)

Direct transfer of genetic material between bacteria through direct cell-to-cell contact occurs during conjugation. A donor cell carrying the F factor (F+) forms a sex pilus to attach to a recipient cell lacking the F factor (F−). The mating bridge lets the plasmid (or sometimes chromosomal DNA) be transferred from donor to recipient, usually as a single DNA strand that is replicated in both cells, so the recipient becomes F+. This requirement for physical contact and a specialized transfer system is what sets conjugation apart from other gene‑transfer methods. In transformation, bacteria take up free DNA from the environment without any connection between cells; transduction uses a bacteriophage to move DNA; electroporation is a lab technique that uses an electric field to permeabilize membranes to introduce DNA.

Direct transfer of genetic material between bacteria through direct cell-to-cell contact occurs during conjugation. A donor cell carrying the F factor (F+) forms a sex pilus to attach to a recipient cell lacking the F factor (F−). The mating bridge lets the plasmid (or sometimes chromosomal DNA) be transferred from donor to recipient, usually as a single DNA strand that is replicated in both cells, so the recipient becomes F+. This requirement for physical contact and a specialized transfer system is what sets conjugation apart from other gene‑transfer methods. In transformation, bacteria take up free DNA from the environment without any connection between cells; transduction uses a bacteriophage to move DNA; electroporation is a lab technique that uses an electric field to permeabilize membranes to introduce DNA.