Aresearcher has a petri dish containing several species of bacteria, but no viruses. she notices that the population of e. coli in her petri dish has no antibiotic resistance. two weeks later, she reassesses the bacteria and finds that the e. coli have acquired antibiotic resistance. how could this have happened?

Bacteria can get antibiotic-resistant gene through the process of transformation, conjugation, and transduction. In transduction, the virus is required to provide the extra gene to the bacteria.

In transformation bacteria takes the genetic material from its surroundings and in conjugation bacteria can take or transfer antibiotic-resistant gene by sex pills. Therefore in this case virus is not present then transduction can not contribute to the antibiotic resistance gene to E.coli.

So conjugation and transformation are the methods by which E.coli can acquire antibiotic-resistant genes from other bacterial species.