Gene regulation governing lactose operon of E. coli that involves the lac I gene product is:
- Positive and inducible because it can be induced by lactose
- Negative and inducible because repressor protein prevents transcription
- Negative and repressible because repressor protein prevents transcription
- Feedback inhibition because excess of - galactosidase can switch off transcription
Solution
In negative regulation, a repressor molecule binds to the operator of an operon and terminates transcription. The lac operon is a negatively controlled inducible operon, where the inducer molecule is allolactose.
Asked in: NEET 2015 (Phase 1)
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