KCET · BIOLOGY · STD 12 - 5. Molecular Basis of Inheritance
Which of the following events would occur in 'Lac operon' of E. coli when the growth medium has high concentration of lactose?
- A The repressor protein attaches to the promoter sequence and derepresses the operator.
- B The structural genes fail to produce polycistronic mRNA
- C The inducer Molecule binds to repressor protein and RNA polymerase binds to promoter sequence.
- D The repressor protein binds to RNA polymerase and prevents tanslation.
Answer & Solution
Correct Answer
(C) The inducer Molecule binds to repressor protein and RNA polymerase binds to promoter sequence.
Step-by-step Solution
Detailed explanation
(C) The inducer Molecule binds to repressor protein and RNA polymerase binds to promoter sequence.,
Lactose (or allolactose) acts as inducer in 'Lac' operon model. When lactose is present in high concentration in growth medium, it binds to repressor protein, which then fails to bind to operator gene. This results in RNA polymerase binding to promoter region in gene and transcription of structural genes.
Lactose (or allolactose) acts as inducer in 'Lac' operon model. When lactose is present in high concentration in growth medium, it binds to repressor protein, which then fails to bind to operator gene. This results in RNA polymerase binding to promoter region in gene and transcription of structural genes.
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