Question

To describe transforming principle, Frederick Griffith performed series of experiments by selecting two strains of Streptococcus pneumoniae namely S-strain (virulent) and R-strain (non-virulent).
Which of the following steps does not describe this experiment?
[0.7 mark]

• A. S-strain live $\stackrel{Injectedintomice}{\to }$Mice die
• B. S-strain (heat-killed) + R-strain (live)$\stackrel{Injectedintomice}{\to }$Mice die
• C. R-strain (heat-killed) + S-strain (live)$\stackrel{Injectedintomice}{\to }$Mice live
• D. S-strain (heat-killed)$\stackrel{Injectedintomice}{\to }$Mice live

Answer 1

The correct option is C R-strain (heat-killed) + S-strain (live)$\stackrel{Injectedintomice}{\to }$Mice live

When the mixture of S-strain (heat-killed) and R-strain (live) of Streptococcus pneumoniae bacteria was injected to the mice, the mice died. It was due to the transformation of R-strain by heat-killed S-strain bacteria.

Injection of R-strain (heat-killed) and S-strain (live) into the mice caused the mice died due to virulent live S-strain.