Which scientist is associated with the term 'Nuclein'?

$DNA$ was first discovered by

$P$ is the stable genetic material,whereas $Q$ performs active roles like messenger and adapter. Identify $P$ and $Q$.
$\quad\quad P \quad \quad \quad Q$

$A$ molecule that can act as a genetic material must possess which of the following characteristics?

When did Frederick Griffith conduct a series of experiments using bacteria?

During the course of evolution,why was $DNA$ chosen over $RNA$ as the genetic material? Provide reasons by first discussing the desired criteria for a molecule to act as genetic material and by analyzing the biochemical differences between $DNA$ and $RNA$.