Select the two correct statements out of the four(a-d) below about lac operon

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Select the two correct statements out of the four(a-d) give below about lac operon.
(i) Glucose or galactose may bind with the repressor and inactive it
(ii) In the absence of lactose the represor binds with the operator region
(iii) The z-gene codes for permease
(iv) This was elucidated by Francois Jacob and Jacque Monod.
The correct statements are:

Options

(a) (ii) and (iii)
(b) (i) and (iii)
(c) (ii) and (iv)
(d) (i) and (ii)

Correct Answer:

(ii) and (iv)

Explanation:

Jacob and Monod proposed the lac operon of E. coli. The lac operon contains a promoter, an operator, and three strctural genes called z, y and a, coding for the enzyme, galactosidase, permease and transacetylase respectively. The lack regulator agene, designated as i gene, codes for repressor. In the absence of the inducer, the repressor binds to the lac operator, preventing RNA, polymerase from binding to the promoter and thus transcribing the structural gene.

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Topics: Genetics (204)
Subject: Biology (4253)

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