Explain the role of the following scientists in the field of genetics:
$1.$ Francis Crick
$2.$ Frederick Griffith $(1928)$

(N/A) Francis Crick proposed the Central Dogma in molecular biology, which states that genetic information flows from $DNA \rightarrow RNA \rightarrow \text{Protein}$.
Frederick Griffith, in his experiment with $Streptococcus \text{ } pneumoniae$, concluded that the $R$-strain bacteria had been 'transformed' by the heat-killed $S$-strain bacteria. He suggested that some 'transforming principle' was transferred from the heat-killed $S$-strain to the $R$-strain, enabling the $R$-strain to synthesize a smooth polysaccharide coat and become virulent.