What is the process by which one type of bacterium is permanently changed into another?

What is the process by which one type of bacterium is permanently changed into another?

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

Answer: (B)

This question tests how bacteria can acquire new genetic information that leads to a stable, heritable change in type. Transformation is the uptake of naked DNA from the surrounding environment by a bacterium, and when that DNA is integrated into the recipient’s genome, the cell gains new traits and is permanently changed. This is a classic example of horizontal gene transfer, producing a lasting shift in genotype and phenotype. This differs from transduction, where DNA is moved from one bacterium to another via a bacteriophage, and from conjugation, where DNA transfer occurs through direct cell-to-cell contact and a pilus. Mutation is a change in the bacterium’s own DNA sequence, not the acquisition of external DNA.

This question tests how bacteria can acquire new genetic information that leads to a stable, heritable change in type. Transformation is the uptake of naked DNA from the surrounding environment by a bacterium, and when that DNA is integrated into the recipient’s genome, the cell gains new traits and is permanently changed. This is a classic example of horizontal gene transfer, producing a lasting shift in genotype and phenotype.

This differs from transduction, where DNA is moved from one bacterium to another via a bacteriophage, and from conjugation, where DNA transfer occurs through direct cell-to-cell contact and a pilus. Mutation is a change in the bacterium’s own DNA sequence, not the acquisition of external DNA.