Which method describes the uptake of naked DNA from the environment by bacteria, often enhanced by chemical treatment?

Which method describes the uptake of naked DNA from the environment by bacteria, often enhanced by chemical treatment?

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

Answer: (A)

Transformation is the uptake of naked DNA from the environment by bacteria. In the lab, this process is often made more efficient by chemical treatments that render cells competent, such as calcium chloride, which help DNA cross the cell membrane during a brief heat shock. Once inside, the DNA can recombine into the genome or exist as a plasmid. This is distinct from transduction, where DNA is transferred by a bacteriophage; from conjugation, which requires direct cell-to-cell contact and a pilus-mediated transfer; and from electroporation, which uses an electric pulse to transiently permeabilize the membrane to allow DNA entry. Thus, the described method matches transformation.

Transformation is the uptake of naked DNA from the environment by bacteria. In the lab, this process is often made more efficient by chemical treatments that render cells competent, such as calcium chloride, which help DNA cross the cell membrane during a brief heat shock. Once inside, the DNA can recombine into the genome or exist as a plasmid. This is distinct from transduction, where DNA is transferred by a bacteriophage; from conjugation, which requires direct cell-to-cell contact and a pilus-mediated transfer; and from electroporation, which uses an electric pulse to transiently permeabilize the membrane to allow DNA entry. Thus, the described method matches transformation.