A Microbiologist Is Working with Two Separate Cultures of the Same

Multiple Choice

A microbiologist is working with two separate cultures of the same organism. The bacteria in one culture are resistant to penicillin, whereas the bacteria in the other culture are susceptible to penicillin. The bacteria from both cultures are mixed together, and all the resulting bacteria are resistant to penicillin. What caused this phenomenon?

A) The plasmid carrying the resistance gene was transferred to the susceptible population of bacteria.
B) The plasmid carrying the susceptibility gene was transferred to the resistant population of bacteria.
C) An IS element was inserted into the genome of the susceptible bacterial population.
D) A frame-shift mutation occurred that allowed the susceptible population of bacteria to develop resistance to penicillin.