The component responsible for heredity is .......

Give an account of the Hershey and Chase experiment. What did it conclusively prove? If both $DNA$ and proteins contained phosphorus and sulphur,do you think the result would have been the same?

$A$ series of experiments were conducted by Frederick Griffith in $1928$,on the transforming principle with:

Analyze the following experimental steps performed by Frederick Griffith:
$I - R$ strain $\rightarrow$ injected into mice
$II - S$ strain $\rightarrow$ injected into mice
$III - S$ strain (heat-killed) $\rightarrow$ injected into mice
$IV - S$ strain (heat-killed) $+ R$ strain (live) $\rightarrow$ injected into mice
In which of the above stages will the mice remain alive?

Following representations $P$,$Q$ and $R$ denote few steps of the Griffith Experiment. Identify the correct one$(s)$:
$P. R$ strain $\rightarrow$ Inject into mice $\rightarrow$ Mice die
$Q. S$ strain (Heat killed) $\rightarrow$ Inject into mice $\rightarrow$ Mice die
$R. R$ strain $\rightarrow$ Inject into mice $\rightarrow$ Mice live

What happens if heat-killed $R$-strain and live $S$-strain bacteria are injected into a mouse?