In the screening process during rDNA experiments, clones that metabolize $\beta$-gal turn:

1. Colorless

2. Blue

3. Yellow

4. Green

The colonies of recombinant bacteria appear white in contrast to blue colonies of non-recombinant bacteria because of 

(1) Non-recombinant bacteria containing $\beta$-galactosidase

(2) Insertional inactivation of $\alpha$-galactosidase in non-recombinant bacteria

(3) Insertional inactivation of β-galactosidase in recombinant bacteria

(4) Inactivation of glycosidase enzyme in recombinant bacteria

How are transformants selected from nontransformants?

1. Presence of more than one recognition site in the vector DNA.

2. Presence of alien DNA into the vector DNA results into insertional inactivation of selectable marker.

3. Antibiotic resistance gene gets inactivated due to insertion of alien DNA.

4. Both 2 and 3.

Insertional inactivation of a gene helps in
a. Identification of recombinant clones
b. Identification of deletion mutants
c. Identification of recombinant transformants
d. Elimination of suppression mutants

Insertional inactivation of the lac Z gene forms-

A reporter enzyme used in biotechnology is-

Which of the following would you choose as the safest and least cumbersome selectable marker-

If the gene of Beta-galactosidase is not inactivated, means there will be color in the colonies of

1.      Non- recombinant

2.      Recombinant

3.      Transformants

4.     Non-transformants

Insertional inactivation results in

1.      Non-recombinants

2.      Recombinants

3.      Transformants

4.     Non- transformants

In the screening process, clones that metabolize X-gal turn

1. yellow

2. orange

3. blue

4. colorless