$DNA$ was first discovered by

The Hershey and Chase experiment is given below. What are the processes $P, Q,$ and $R$?
$\quad\quad \quad P \quad\quad\quad Q \quad \quad\quad R$

If $DNA$ contained sulphur instead of phosphorus and proteins contained phosphorus instead of sulfur,what would have been the outcome of Hershey and Chase experiment?

What could not be determined from Griffith's experiment?

Which of the following was responsible for the transformation of $R$ cells into $S$ cells?

Who invented the method of identification of nutrient characters in $Neurospora$ $crassa$?