The regulation of the $lac$ operon by a repressor is known as:

The one gene-one enzyme hypothesis was postulated by

An organism is able to survive on a culture medium containing nutrient $A$ through an enzyme-catalyzed process: $A \xrightarrow{X} B \xrightarrow{Y} C$. $A$ mutant organism fails to survive on this medium. However,it grows when nutrient $B$ is added to the medium. Which gene of this mutant is defective?

What is the structural gene equivalent to?

What happens if an $ATT$ sequence appears in the middle of the template strand of the $Lac\, y$ gene?

In $Drosophila$,the set of homeotic genes that control the body plan during organ differentiation is known as.......