Type S Streptococcus pneumoniae bacterium is lethal and will kill its host.If heat inactivated the S strain dies and becomes nonlethal.Type R Streptococcus pneumoniae is a nonvirulent strain of bacteria.What would occur if one were to inject both the R strain and heat-killed S strains into a host organism such as the mouse?
A)The S strain would be transformed into the nonvirulent R strain and kill the host.
B)The R strain would be transformed into the virulent S strain and kill the host.
C)The S strain would be transformed into the nonvirulent R strain and not affect the host.
D)The R strain would be transformed into the virulent S strain and not affect the host.
E)Neither the S nor the R strain would changE.

Question

Quizplus · Accepted Answer

The R strain of Streptococcus pneumoniae can take up DNA from the heat-killed S strain, leading to a transformation that makes the R strain virulent, thus potentially killing the host. This is a classic demonstration of bacterial transformation.

Type S Streptococcus Pneumoniae Bacterium Is Lethal and Will Kill