DNA strands on a gel, stained with ethidium bromide, when viewed under UV radiation, appear as:

1.	Dark red bands	2.	Bright blue bands
3.	Yellow bands	4.	Bright orange bands

Which of the following is a correct sequence of steps in a PCR (Polymerase Chain Reaction)?

1. Extension, Denaturation, Annealing

2. Annealing, Denaturation, Extension

3. Denaturation, Annealing, Extension

4. Denaturation, Extension, Annealing

During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out:

Plasmid pBR322 has a PstI restriction enzyme site within gene amp^R that confers ampicillin resistance. If this enzyme is used for inserting a gene for $\mathrm{\beta }$-galactoside production and the recombinant plasmid is inserted in an E.coli strain,

A specific recognition sequence identified by endonucleases to make cuts at specific positions within the DNA is: 

1. Palindromic Nucleotide sequences

2. Poly(A) tail sequences

3. Degenerate primer sequence

4. Okazaki sequences

During the process of gene amplification using PCR, if a very high temperature is not maintained in the beginning, then which of the following PCR will be affected first? 

In Lederberg's replica plating experiment, what shall be used to obtain streptomycin resistant strain?
1.  Minimal medium and streptomycin
2.  Complete medium and streptomycin
3.  Only minimal medium
4.  Only complete medium

Manipulation of DNA in genetic engineering became possible due to the discovery of:

1. Restriction endonuclease

2. DNA ligase

3. Transcriptase

4. Primase

Which of the following enzymes are used to join bits of DNA:

1. Ligase

2. Primase

3. DNA polymerase

4. Endonuclease

Restriction endonucleases: