Question

Lac operon model was proposed by

• A. Jacob and Monod
• B. Jacob and Wollman
• C. Jacob and Nirenberg
• D. Jacob and Wilkins

Answer 1

Answer: (A)

Jacob and Monod

The lac operon is an operon responsible for transport and metabolism of lactose in Escherichia coli and other bacteria. The mechanisms of regulation of expression of genes responsible for coding the involved enzymes was first explained by Francois Jacob and Jacque Monad while working on inducible system for synthesis of beta-galactosidase enzyme in E. coli. According to the model, an operon cosists of operator gene and structural genes. The operator gene regulates the expression of structural genes by providing a binding site to transcription factor which in turn regulate the gene expression by altering the binding of RNA polymerase to the promoter region. Option A is correct answer.