The underlying basis of the Polymerase Chain Reaction is:
1. | DNA synthesis and hence amplification can occur in a template independent manner. |
2. | DNA, being thermostable, can be amplified during the thermal cycle in PCR. |
3. | DNA polymerase I can synthesize large amounts of DNA. |
4. | PCR allows the direct amplification of DNA even if it is present in minute quantities. |
DNA fragments digested by restriction endonucleases separate on agar gel electrophoresis according to their size because:
1. | they are forced to move towards cathode under an electric field |
2. | agar gel provides a sieving effect |
3. | larger fragments will have more negative charge and will move farther in the electric field |
4. | chelation with ethidium bromide reduce the rate of transport of fragments |
Plasmid pUC18 carries lacZ gene that confers the host cells to convert white X-gal into blue indole. A gene is inserted within the lacZ gene of the plasmid. Bacterial cells transformed with this rDNA, if provided with X-gal in the medium, will produce:
1. | Blue colonies |
2. | White colonies |
3. | No colonies |
4. | Orange colonies if seen through UV light |
A cloning vector must:
1. | be able to maintain a very high copy numbers of their genome in the host cells |
2. | contain elements such as promoter and ribosome binding sites |
3. | be engineered to carry a large number of recognition sequences for common restriction enzymes |
4. | be able to replicate within host cell independent of the control of chromosomal DNA |
Some bacteria are resistant to antibiotics. This trait is normally due to:
1. lack of membrane bound organelles
2. presence of a cell wall
3. presence of an extra-chromosomal circular DNA
4. a unique feature called as inclusion bodies
The downstream processing stage of rDNA does not involve:
1. | Biosynthesis | 2. | Separation |
3. | Purification | 4. | Preservation |
In microinjection, the rDNA :
1. | coats the micropellets and is used in biolistics to transform plant cells |
2. | is directly injected into the cytoplasm of a plant or an animal cell |
3. | is delivered in the vicinity of the plasma membrane of the cell (to be transformed) |
4. | is directly injected into the nucleus of an animal cell |
Which of the following can be used to induce competence for getting a bacterial cell transformed during rDNA procedures?
1. | A divalent cation | 2. | Ethidium bromide |
3. | Polyethylene glycol | 4. | Anionic proteins |
The Ti plasmid, used in transformation of plant cells, is found in:
1. | Agrobacterium tumefaciens | 2. | Escherichia coli |
3. | Bacillus thuringiensis | 4. | Xanthomonas citri |
If we are able to link an alien piece of DNA with bacteriophage or plasmid DNA, we can multiply its number:
1. | more than the number of copy number of bacteriophages in the cells and equal to the copy number of plasmid in the cell. |
2. | equal to the number of copy number of bacteriophages in the cells and equal to the copy number of plasmid in the cell. |
3. | equal to the number of copy number of bacteriophages in the cells and less than the copy number of plasmid in the cell. |
4. | less than the number of copy number of bacteriophages in the cells and more than the copy number of plasmid in the cell. |