Which mechanism does not require direct contact between donor and recipient because DNA is taken up from the environment?

Which mechanism does not require direct contact between donor and recipient because DNA is taken up from the environment?

• A. Transformation
• B. Binary Fission
• C. Conjugation
• D. Transduction

Answer: (A)

Transformation is the uptake of naked DNA from the surrounding environment by a competent bacterium. In this process, DNA is already present outside the cell—often released when another cell lyses—so the recipient can grab fragments or plasmids without needing to touch another cell directly. Once inside, the foreign DNA can be integrated into the chromosome by recombination or maintained as a plasmid, spreading traits like antibiotic resistance. This differs from conjugation, which requires direct cell-to-cell contact via a pilus to transfer DNA, and from transduction, where a bacteriophage ferries DNA from one cell to another. Binary fission isn’t about transferring DNA between cells at all; it’s the asexual replication of a single cell.

Transformation is the uptake of naked DNA from the surrounding environment by a competent bacterium. In this process, DNA is already present outside the cell—often released when another cell lyses—so the recipient can grab fragments or plasmids without needing to touch another cell directly. Once inside, the foreign DNA can be integrated into the chromosome by recombination or maintained as a plasmid, spreading traits like antibiotic resistance. This differs from conjugation, which requires direct cell-to-cell contact via a pilus to transfer DNA, and from transduction, where a bacteriophage ferries DNA from one cell to another. Binary fission isn’t about transferring DNA between cells at all; it’s the asexual replication of a single cell.