This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Operon model was elucidated by 
Select and explain. 
A. Jacob & Monad, B. Waston & Crick, C. Leiderburg & Tautum, D. Two D Herell
A: Jacob & Monad
Answer: A: Jacob & Monad 
Explanation: FRANCOIS JACOB and JACQUES MONAD put forward the operon concept in 1965Theory was based on the observation on lactose metabolism in Escherichia coliRef: DM Vasudevan, 7th edition, page no: 617