Select the $correct$ match:

Given below are two statements:
Statement $I$: In lac operon,the repressor protein binds to the promoter region of the operon and prevents $\text{RNA}$ polymerase from transcribing the operon.
Statement $II$: Regulation of lac operon can also be visualized as regulation of enzyme synthesis by its substrate.
In the light of the above statements,choose the correct answer from the options given below:

Describe the regulation of gene expression in prokaryotes with an example.

The diagram below shows a diagrammatic sketch of the maturation of insulin. Select the correct set of names labeled $A, B, C$,and $D$.

All of the following are part of an operon except:

Write a short note on the lac operon.