Final answer:
Frederick Griffith was the first to demonstrate bacterial transformation using mice and two strains of Streptococcus pneumoniae. He showed that the live, nonpathogenic R strain of bacteria could be transformed into the pathogenic S strain through exposure to heat-killed S strain. This experiment proved the role of DNA in hereditary information transfer.
Step-by-step explanation:
Frederick Griffith was the first to demonstrate the process of bacterial transformation using mice and two strains of Streptococcus pneumoniae. In 1928, he showed that the live, nonpathogenic R strain of bacteria could be transformed into the pathogenic S strain through exposure to heat-killed S strain. This experiment proved that hereditary information could be transferred horizontally from one cell to another through DNA.