The lac in lac operon refers to

(1)lactose but not lactase

(2)lactase but not lactose

(3)lactobacillus but not lactose

(4)lactose as well as laevorotatory

Select the correct match:

1. Alec Jeffreys – Streptococcus pneumoniae

2. Alfred Hershey and Martha Chase – TMV

3. Matthew Meselson and F. Stahl – Pisum sativum 

4. Francois Jacob and Jacques Monod – Lac operon 

The inducer of lac operon is :

1. Beta galactosidase

2. Galactose

3. Lactose

4. Glucose

Select the two statements out of the four (A - D) given below about lac operon.

(A) Glucose or galactose may bind with the repressor and inactivate it

(B) In the absence of lactose, the repressor binds with the operator region

(C) The z-gene codes for permease

(D) This was elucidated by Francois Jacob and Jacques Monod

The correct statements are

1. (B) and (C)

2. (A) and (C)

3. (B) and (D)

4. (A) and (B)

Lac operon will be switched on when

(1) lactose is less in the medium

(2)glucose is enough in the medium

(3)lactose is less than glucose

(4)lactose is more than glucose

For lactose metabolism

(1) all three gene products are required

(2) only regulator gene products are required

(3) only Beta-galactosidase are required

(4) Beta-galactosidase and permease are required

Column-I                                        Column-II
I. Operator site                               A. Binding site for RNA polymerase
II. Promoter site                              B. Binding site for repressor molecule
III. Structural gene                          C. Codes for enzyme protein
IV. Regulator gene                          D. Code for repressor molecules
The correct match is:
(1) I - B, II - A, III - C, IV - D         

(2) I - B, II - A, III - D, IV - C

(3) I - D, II - C, III - A, IV - B         

(4) I - B, II - C, III - A, IV - D

In the lac operon model, lactose molecules function as:-

(1) inducers, which bind with the operator
gne

(2) repressors, which bind with the operator
gene

(3) inducers, which bind with the repressor
protein

(4) corepressors, which bind with repressors
protein

Promoter regions of lac operon can be accessed by

(1)RNA polymerase

(2)DNA polymerase

(3)Proteins

(4)All of these

In lac operon

(1) 3 structural, 1 operator and 2 promoter genes are present

(2) 3 structural, 1 operator and 1 promoter genes are present

(3) 3 structural, 2 operator and 1 promoter genes are present

(4) 3 structural, 1 operator and 3 promoter genes are present