Molecular Biology of the Gene: Structure, Function, and Expression

In the experiment depicted, a mixture of heat-killed smooth (S) cells and live rough (R) cells was treated with different enzymes before being injected into mice. Which enzyme treatment prevented the transformation of R cells into pathogenic S cells, allowing the mice to live?

What conclusion can be drawn from the result that mice lived only when DNase was added to the mixture of dead S cells and live R cells?

If the experiment was repeated with the addition of protease, what would be the expected outcome for the mice, and what does this indicate about the role of protein in genetic transformation?