What is the term for the uptake of environmental DNA by a bacterium resulting in a permanent genetic change?

What is the term for the uptake of environmental DNA by a bacterium resulting in a permanent genetic change?

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

Answer: (A)

The concept being tested is horizontal gene transfer by taking up DNA from the environment and making a heritable change. When a bacterium takes up environmental DNA and that DNA recombines into its genome or is maintained as a replicating element, the new genetic information becomes a permanent part of that cell and its descendants. This specific process is transformation. It’s different from transduction, where a bacteriophage carries DNA from one cell to another, not environmental DNA; and from conjugation, which requires direct cell-to-cell contact and typically transfers plasmids. Mutation, meanwhile, is a change in DNA sequence that arises on its own or due to mutagens, not through uptake of external DNA.

The concept being tested is horizontal gene transfer by taking up DNA from the environment and making a heritable change. When a bacterium takes up environmental DNA and that DNA recombines into its genome or is maintained as a replicating element, the new genetic information becomes a permanent part of that cell and its descendants. This specific process is transformation. It’s different from transduction, where a bacteriophage carries DNA from one cell to another, not environmental DNA; and from conjugation, which requires direct cell-to-cell contact and typically transfers plasmids. Mutation, meanwhile, is a change in DNA sequence that arises on its own or due to mutagens, not through uptake of external DNA.