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
A plasmid has a single recognition sequence for EcoRI. When cut with this enzyme, the number of resultant fragments will be:
1. 1
2. 2
3. 3
4. 4