Promoter regions of lac operon can be accessed by
1. RNA polymerase
2. DNA polymerase
3. Proteins
4. All of these
Promoter regions of lac operon can be regulated by
1. operator region only
2. structural region
3. both operator and structural region
4. operator , structural and promoter region
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
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
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
In lac operon, repressor is inactivated by
1. interaction with enzyme
2. interaction with protein
3. interaction with carbohydrate
4. interaction with nucleic acid
Lac operon is an example of
1. both positive and negative regulation
2. only negative regulation
3. only positive regulation
4. sometimes positive sometimes negative
Lac operon inhibition by repressor is an example of
1. negative regulation
2. positive regulation
3. neither positive nor negative
4. both positive and negative regulation
Regulation of lac operon can be visualised as regulation of enzyme synthesis by its
1. substrate
2. lactose
3. carbohydrates
4. All of these