A researcher is conducting an experiment on bacterial antibiotics resistance genes. Bacterial strain A is resistant to vancomycin; strain B is not. Both strains are incubated together over many generations of growth. It is now shown that bacterial strain B is resistant to vancomycin. Which of the following best supports conjugation as the mechanism of antibiotics resistance gene acquisition?
Direct cell to cell contact
Disruption with the addition of nucleotidase
Lysogenic phase
Lytic phase without lysogeny
Viral DNA flanked by bacterial DNA
