Answer :
Final answer:
Griffith's experiment with smooth and rough strains of Streptococcus pneumoniae demonstrated the transfer of genetic material between bacteria, a phenomenon known as bacterial transformation. So the correct option is a) The role of viruses in bacterial transformation.
Explanation:
Griffith's experiment with smooth and rough strains of Streptococcus pneumoniae demonstrated the transfer of genetic material between bacteria. This process, now known as bacterial transformation, was shown when Griffith worked with two strains of this bacterium known as rough (R) and smooth (S). The rough strain produced nonpathogenic colonies with an uneven surface, while the smooth strain had a capsule that gave it a smooth appearance and was pathogenic, causing disease. In his experiments, Griffith found that when he injected mice with a mixture of live R strain and heat-killed S strain, the mice died, and live S strain bacteria were later isolated from them, indicating a transfer of the pathogenic trait from the dead S strain to the living R strain.
