DNA Ligase, used in recombinant DNA technology is obtained from _______________

Consider the following statements.
I. T4 DNA ligase can catalyze blunt end Ligation more efficiently than E. coli DNA ligase.
II. The ligation efficiency of T4 DNA Ligase can be increased with PEG and ficoll.

A

Only I is true

B

Both I and II are true

C

Only II is true

D

I is true and II is false

Steps of Recombinant DNA technology are given below.
1. Identification and isolation of the genetic material.
2. Fragmentation of DNA.
3. Obtaining the foreign gene product.
4. Downstream processing.
5. Ligation of DNA fragmentation into the vector.
6. Isolation of desired DNA fragments.
7. Amplification of gene of interest.
8. Transfer of Recombinant DNA into the host cell/organism.
The correct sequence of steps is

A

3, 1, 2, 4, 6, 5, 7, 8

B

1, 4, 3, 2, 5, 7, 6, 8

C

1, 2, 6, 7, 5, 8, 3, 4

D

8, 6, 7, 5, 1 , 4, 2, 3

Mechanism of ligation for both T4 DNA ligase and E. coli DNA ligase makes use of Adenosine Monophosphate (AMP). Which of the steps is involved in the ligation mechanism?

A

AMP is added to the 5’ phosphate of one of the DNA molecule

B

It leads to the liberation of pyrophosphate from NAD and nicotinamide mononucleotide from ATP

C

The AMP is further displaced by an electrophilic attack

D

The AMP is further displaced by nucleophilic attack by 3’ hydroxyl of the same DNA molecule

In recombinant DNA technology, what molecule is the most commonly used DNA vector (or carrier, used to insert foreign genetic material into an organism’s genome)?

A

clone

B

cell

C

plasmid

D

gene

Consider the following statements regarding DNA replication and choose the correct answer:
1. The very first requirement of DNA synthesis is the presence of a template or plan along which the new strand is to be constructed
2. The second requirement is of a DNA-dependent-DNA polymerase or simply DNA polymerase enzyme
3. A DNA Pol cannot join two free nucleotides; one of them must be anchored by hydrogen bonds to a DNA strand
4. Replication takes place bidirectionally

A

1, 2, 3 and 4 are true

B

Only 2 and 4 are true

C

Oniy 2, 3 and 4 are true

D

Only 1 and 2 are true

What is the reaction in DNA replication catalyzed by DNA ligase?

A

Addition of new nucleotides to the leading strand

B

Addition of new nucleotide to the lagging strand

C

Formation of a phosphodiester bond between the 3’-OH of one Okazaki fragment and the 5’-phosphate of the next on the lagging strand

D

Base pairing of the template and the newly formed DNA strand

DNA ligase can ligate restriction site ends produced by EcoRI to the ends of DNA insert cut by the same enzyme.

A

True

B

False

The gaps formed by the hydrolyzing the RNA from RNA:DNA hybrid is filled by DNA polymerase I and the nicks are ligated by T4 ligase.

A

True

B

False

The schematic of a plasmid with a gap in one of the strands is shown below:
Which of the following enzyme(s) is/are required to fill the gap and generate a covalently closed circular plasmid?
P. DNA ligase
Q. Alkaline phosphatase
R. DNA polymerase
S. Polynucleotide kinase

A

P only

B

P, R and S only

C

P and R only

D

P, Q and R only

Correct answer for the given blank out of the four alternatives.
The main failings were of conception and a political willingness to settle _________ easy options. _______________ the expansive declarationsof the need "to maintain effective security of all nuclear materials, _______________ includes nuclear materials used in nuclear weapons”, thesummits narrowed their _______________ to civilian holdings __________________ nonnuclear weapon states.
_______________ includes nuclear materials used in nuclear weapons”

A

which

B

that

C

those

D

who

DNA Ligase, used in recombinant DNA technology is obtained from _______________

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