Restriction enzymes do not act on the DNA of the host cell in which they are produced, because :
1. | Host DNA is packed into chromosomes |
2. | Restriction enzymes are ineffective on host DNA |
3. | Host DNA does not have the restriction site for the restriction enzymes. |
4. | Restriction site of host DNA is methylated. |
In the first gene cloning experiment:
1. | Researchers successfully identified a human gene responsible for the disease. |
2. | Researchers successfully inserted a gene for kanamycin resistance into a plasmid vector. |
3. | Researchers demonstrated that many different DNA fragments could insert into a plasmid vector |
4. | Researchers produced a strain of bacteriophage with an increased ability to infect E. coli. |
A circular plasmid of 10000 bp is digested with two restriction enzymes A and B, to produce 3000 bp and 2000 bp bands when visualized on an agarose gel. When digested with one enzyme at a time, only one band is visible at 5000 bp. If the first site for enzyme A [A1] is present at the 100th base, the order in which the remaining sites [A2, B1 and B2] are present is:
1. | 5100, 3100, 8100 | 2. | 3100, 5100, 8100 |
3. | 8100, 5100, 3100 | 4. | 8100, 3100, 5100 |
When the phage DNA enters a bacterium, it protects itself from the viral DNA with the help of:
1. | methylases | 2. | endonucleases |
3. | exonucleases | 4. | ligases |
What is the problem in providing a bone marrow transplant to a patient of SCID as a treatment?
1. rejection of the graft by the recipient
2. graft-versus-host disease
3. cardiovascular failure
4. anaphylaxis
Assertion (A): | In order to link the alien DNA, the vector needs to have very few, preferably single, recognition sites for the commonly used restriction enzymes. |
Reason (R): | Presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning. |
1. | Both (A) and (R) are True and the (R) is the correct explanation of (A) |
2. | Both (A) and (R) are True but the (R) is not the correct explanation of (A) |
3. | (A) is True but (R) is False |
4. | Both (A) and (R) are False |
Assertion (A): | When constructing rDNA, the vector DNA should never be cut by the same restriction endonuclease that was used to cut the donor DNA |
Reason (R): | Use of same restriction endonuclease will generate same kind of sticky ends retarding the function of DNA ligase. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A) |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A) |
3. | (A) is True but (R) is False |
4. | Both (A) and (R) are False |
1. | EcoR I | 2. | Hind II |
3. | Bam HI | 4. | Sma I |