The coupling and repulsion theory was proposed by:

What is the name of the pea species used by Bateson and Punnett in their experiments?

Genes on the same chromosome can be:

The first mutant gene reported by $T.H. Morgan$ in $Drosophila$ was the . . . . . . .

$A$: Morgan's cross $III$ was conducted in $Drosophila$ to locate genes on the chromosome for white eye color.
$R$: The cross was done between red-eyed hybrid female and white-eyed male.

Who clearly proved and defined linkage?