Question

Recall the experiments done by Frederick Griffith, Avery, $\text{MacLeod}$ and McCarty, where $DNA$ was speculated to be the genetic material. If $RNA,$ instead of $DNA,$ was the genetic material, would the heat killed strain of Pneumococcus have transformed the $R-\text{strain}$ into virulent strain? Explain.

Answer 1

RNA as a transforming material:

$RNA$ is a highly reactive and labile molecule due to the presence of $2^{\prime }-OH$ group in the ribose sugar.

Upon heating, RNA of heat killed $S$ strain may degrade and not remain as stable as $DNA.$

Hence $RNA$ wpo not have transformed the $R$ strain bacteria of Pneumococcus into virulent $S$ strain.