Q. In lac operon system, i gene codes for :
(a) Inducer of lac operon
(b) Repressor of lac operon
(c) Hydrolysis and disaccharide
(d) Permease
Solution :
Correct option :B Operon is a cluster of structural genes found as a group. The lac operon is an inducible operon that utilizes lactose as an energy source and is activated when glucose is low and lactose is present. The lac operon contains an operator, promoter and structural genes which are transcribed together and are under the control of the repressor. The lac operon encodes genes that needs to acquire and process the lactose from the local environment. These are of different types- I, P, O, lac Z, lac Y and lac A. Of these lac I gene codes for repressor protein.