NEET Botany Molecular Basis of Inheritance Questions Solved

BOARD

Write the different components of a lac-operon in E.coli. Explain its expression while in an ‘open’ state. 

It consists of one regulatory gene(i) , promotor gene , operator gene , and three structural genes(z,y,a) = ½× 4 

Lactose/ inducer binds to the repressor protein , makes it inactive so it cannot bind with operator, allows RNA Polymerase access to the promotor and transcription proceeds , -galactosidase , permease , transacetylase formed (by translation process for Lactose metabolism ) = ½ × 6

                            (5)

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