Who proposed the ‘Signal hypothesis’ meant for the biosynthesis of secretory type of proteins

A pure breeding pea plant with the dominant phenotype of character $A$ and recessive phenotype of character $B$ was crossed with another pure breeding plant with the recessive phenotype of $A$ and dominant phenotype of character $B. A$ offspring of this cross was crossed with a homozygous recessive for both the characters -$A$ and $B$. The following results are obtained $22$ were phenotypically dominant for $A$ and recessive for $B$.

$4$ were phenotypically dominant for both $A$ and $B$.

$4$ were phenotypically recessive for both $A$ and $B$.

$24$ were phenotypically recessive for $A$ and dominant for $B$.

These results show that

The prokaryotic genetic system contains

The chromosomes as thread like structures in nucleus was first described by

$Y$ gene in lac operon responsible for .....

"Nu body'' was shown by