Which statement about natural gene transfer is true?

Which statement about natural gene transfer is true?

• A. Transformation, transduction, and conjugation are main natural mechanisms.
• B. They require viral vectors exclusively.
• C. Conjugation does not occur in bacteria.
• D. These processes do not contribute to genetic diversity.

Answer: (A)

Natural gene transfer in bacteria occurs through three main mechanisms: transformation, transduction, and conjugation. Transformation is the uptake of naked DNA from the environment by competent cells, allowing new genes to be incorporated into the genome or maintained on plasmids. Transduction involves bacteriophages carrying bacterial DNA from one cell to another during infection, enabling gene movement between bacteria. Conjugation requires direct cell-to-cell contact, usually via a sex pilus, to transfer DNA—often a plasmid such as the F factor—between bacteria. These processes collectively increase genetic diversity by spreading new genes and alleles, including those for antibiotic resistance or novel metabolic capabilities, across populations. The statement is true because they are natural, non-artificial routes for gene transfer, and not all rely on viral vectors exclusively. The other claims—such as conjugation not occurring in bacteria or that these processes don’t contribute to diversity—aren’t accurate.

Natural gene transfer in bacteria occurs through three main mechanisms: transformation, transduction, and conjugation. Transformation is the uptake of naked DNA from the environment by competent cells, allowing new genes to be incorporated into the genome or maintained on plasmids. Transduction involves bacteriophages carrying bacterial DNA from one cell to another during infection, enabling gene movement between bacteria. Conjugation requires direct cell-to-cell contact, usually via a sex pilus, to transfer DNA—often a plasmid such as the F factor—between bacteria.

These processes collectively increase genetic diversity by spreading new genes and alleles, including those for antibiotic resistance or novel metabolic capabilities, across populations. The statement is true because they are natural, non-artificial routes for gene transfer, and not all rely on viral vectors exclusively. The other claims—such as conjugation not occurring in bacteria or that these processes don’t contribute to diversity—aren’t accurate.