Question

The Lac-Operon model was elucidated by

• A. Jacob and Crick
• B. Watson and Crick
• C. Francois Jacob and Jaques Monad
• D. Hershey and Chase

Answer 1

The Correct Option is C

The correct answer is (C) : Francois Jacob and Jaques Monad.

Answer 2

The Lac Operon model is a crucial concept in molecular biology that explains the regulation of gene expression in prokaryotes, specifically in Escherichia coli. This model was elucidated by Francois Jacob and Jacques Monod in 1961, offering a groundbreaking insight into how genes can be turned on or off in response to environmental changes.

The Lac operon is a system that controls the metabolism of lactose in bacteria. It consists of several key components:

• Structural genes: These genes encode enzymes necessary for lactose metabolism.
• Promoter: The site where RNA polymerase binds to initiate transcription.
• Operator: A regulatory region where repressor proteins bind to inhibit transcription.
• Repressor protein: A protein that, when bound to the operator, prevents transcription of the operon's genes.
• Inducer (Lactose): Lactose or its derivative allolactose acts as an inducer by binding to the repressor, causing it to release from the operator, thus allowing gene transcription.

Jacob and Monod's research led to the discovery of negative and positive regulation mechanisms in gene expression, with the Lac operon serving as a classic example of how cells adapt to their environment by regulating the synthesis of enzymes based on the presence or absence of lactose.

The correct answer is: (C) Francois Jacob and Jacques Monod.

Their work on the Lac operon laid the foundation for our understanding of genetic regulation and earned them the Nobel Prize in Physiology or Medicine in 1965.