| I: | is a DNA-dependent DNA polymerase |
| II: | extends the primers in template independent manner |
| III: | is thermostable |
| 1. | Only I and II are correct |
| 2. | Only I and III are correct |
| 3. | Only II and III are correct |
| 4. | I, II and III are correct |
| 1. | Origin of replication (Ori) |
| 2. | Presence of a selectable marker |
| 3. | Presence of sites for restriction endonuclease |
| 4. | Being linear rather than circular |
| 1. | It is extrachromosomal DNA |
| 2. | It is circular and double stranded |
| 3. | It gets replicated with the help of ori of chromosomal DNA |
| 4. | It confers characters like resistance to antibiotics to bacterial cells |
Restriction enzymes produced by some bacteria:
| 1. | cleave phosphodiester bond in the main chromosomal DNA of the bacterium. |
| 2. | cut single stranded DNA at random positions. |
| 3. | prevent the multiplication of bacteriophage in bacteria. |
| 4. | provide resistance against antibiotics. |
The DNA fragments separated on agar gel by electrophoresis can be visualised:
| 1. | without staining in the visible light |
| 2. | without staining on exposure to UV light |
| 3. | after staining with polyethylene glycol followed by exposure to IR radiation |
| 4. | after staining with ethidium bromide followed by exposure to UV radiation |
If an enzyme catalyses the removal of nucleotides from the ends of DNA, then it should be called as:
1. endonuclease
2. exonuclease
3 ligase
4. reverse transcriptase