In a series of experiments, griffith infected mice with nonvirulent r-strain bacteria and highly virulent s-strain bacteria. heat-killed s bacteria were nonvirulent. however, the nonvirulent heat-killed s bacteria and the nonvirulent r bacteria together produced a virulent mixture. what did this demonstrate?
a. the molecules present on the outside of bacteria determine whether it's virulent or nonvirulent.
b. a transforming principle in the s bacteria allowed the nonvirulent r strain to become virulent.
c. the translation of proteins, carbohydrates, lipids, and dna is important in determining bacterial virulence.
d. the s-strain bacteria had not been killed completely.

The correct answer is B.A transforming principle in the S bacteria allowed the nonvirulent R strain to become virulent.

Explanation:

In the transformation experiments, conducted by Fredrick Griffith in 1928, he observed that heat-killed S-strain bacteria injected into mice did not kill them. When he injected a mixture of heat-killed S and live R-bacteria, the mice died. He concluded that the R-strain bacteria had somehow been transformed by the heat-killed S-strain bacteria. This occurred perhaps due to absorption of some transforming principal or substance by rough type bacteria from heat killed smooth bacteria. It had enabled the R-strain to synthesize a smooth polysaccharide coat and become virulent. This must be due to the transfer of the genetic material. However, the biochemical nature of genetic material was defined not from his experiments.