The inducer of lac operon is :

1. Beta galactosidase

2. Galactose

3. Lactose

4. Glucose

Regulation of lac operon by repressor is referred to as:

1. Inducible regulation

2. Repressible regulation

3. Negative regulation

4. Positive regulation

Which enzymes/s will be produced in a cell in which there is a non-sense mutation in the lac Y gene?

(1) β-galactosidase

(2) Lactose permease

(3) Transacetylase

(4) Lactose permease and transacetylase

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)

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

In E.coli the conversion of lactose in galactose and glucose takes place by

(1)Beta-galactokinase

(2) Beta-guluctosidase

(3) Beta-galactosidase

(4) Beta-lactosidase

Promoter regions of lac operon can be accessed by

1. RNA polymerase

2. DNA polymerase

3. Proteins

4. All of these

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

The i-gene in lac operon refers to

1. inducer

2. inhibitor

3. sometimes inducer sometimes inhibitor

4. neither inducer nor inhibitor

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