Which of the given statement is correct in the context of visualising DNA molecules separated by agarose gel electrophoresis?
 

1.	DNA can be seen in visible light.
2.	DNA can be seen without staining in visible light.
3.	Ethidium bromide stained DNA can be seen in visible light
4.	Ethidium bromide stained DNA can be seen under exposure to UV light.

‘Restriction’ in restriction enzyme refers to

Which of the following is not required in the preparation of a recombinant DNA molecule?
1. Restriction endonuclease                   
2. DNA ligase
3. DNA fragments                                   
4. E. coli

In agarose gel electrophoresis, DNA molecules are separated on the basis of their

1. charge only       
2. size only     
3. charge to size ratio       
4. All of the above

The most important feature in a plasmid to serve as a vector in gene cloning experiment is:
1. Origin of replication (ori)
2. Presence of a selectable marker
3. Presence of sites for restriction endonuclease
4. Its size

While isolating DNA from bacteria, which of the following enzymes is not required?
1. Lysozyme                             
2. Ribonuclease
3. Deoxyribonuclease                 
4. Protease

Which of the following has popularised the PCR (Polymerase Chain Reaction)?
1. Easy availability of DNA template
2. Availability of synthetic primers.
3. Availability of cheap deoxyribonucleotides
4. Availability of ‘Thermostable’ DNA polymerase

An antibiotic resistance gene in a vector usually helps in the selection of

1. Competent bacterial cells                             
2. Transformed bacterial cells
3. Recombinant bacterial cells                           
4. None of the above

Significance of 'heat shock' method in bacterial transformation is to facilitate:
 

The role of DNA ligase in the construction of a recombinant DNA molecule is