The correct answer is the Col plasmid, which produce attack proteins called colicins. These are generally small and in many copies in a prokaryote for efficiency. F plasmids are involved in conjugation, R plasmids in resistance, degradative plasmids in digestion of unusual substances, and virulence plasmids in the conversion of certain bacteria into pathogens.

In this example, note that the new genes are being received from a donor bacterium. This is only seen in conjugation events.

Sometimes a bacteriophage can encapsulate host bacterial DNA instead of viral DNA. When this virus infects another bacterium, it will inject the previous bacterium's DNA into the new bacterium. This process is referred to as transduction.

Specialized transduction occurs when a prophages excises from the host bacterial genome incorrectly and brings some of the bacterial chromosome with it. This DNA then gets packaged into viral particles along with the viral genome and gets inserted into the next bacterium that virus infects. Since only lysogenic phage can become prophage, specialized transduction can only be mediated by lysogenic phage. Retroviruses are enveloped and thus infect animal cells, not bacterial cells.

When a bacterium has incorporated DNA from the outside environment into its own genome, the process of transformation has occurred.