Which one is considered as molecular glue in recombinant DNA technology?

1. Endonuclease

2. DNA ligase

3. Polymerase

4. Alkaline phosphatase

The enzyme known as molecular scissors in genetic engineering is

1. DNA ligase

2. Transferases

3. DNA polymerase

4. Restriction endonuclease

Following are the steps in the formation of recombinant DNA by action of a restriction endonuclease. Which one of the given option incorrectly identifies the steps, components labelled as A, B, C, and D?

(1) A - Exonuclease cuts the DNA between bases G and A only when the sequence GAATTC is present in the DNA

(2) B - Sticky ends are formed.

(3) C - The DNA fragments join at sticky ends by DNA ligase.

(4) D - Restriction enzyme Eco RI cuts the strand of DNA a little away from centre of the palindromic sites, but between the same two bases on the opposite strands

If a DNA fragment is cut by EcoRI at a specific recognition site then

1. Blunt-end cannot be obtained

2. Sticky-ends cannot be obtained

3. Construction of rDNA would not be possible

4. The plasmid with one site get cut into two fragments

The first recombinant DNA was constructed
by linking an antibiotic resistant gene with the
native plasmid of
1. Escherichia coli
2. Salmonella typhimurium
3. Clostridium butylicum
4. Acetobacter aceti

Select the correct statement .

1. A restriction exonuclease cuts both strands of foreign DNA as well as vector DNA at specific palindromic sequences

2. A restriction endonuclease is named on the basis of scientific name and strain of bacteria from which it is isolated

3. All restriction enzymes cut the strands of DNA in the centre of palindromic site between the same two bases of opposite strand

4. When cut by same restriction enzyme, the resultant DNA fragments generate different kinds of sticky ends

Read the following statements

Statement-A : Restriction enzymes are obtained only from eukaryotes.

Statement-B : The first discovered restriction endonuclease was EcoRI.

Choose the correct option.

(1) Both statements are correct

(2) Both statements are incorrect

(3) Statement A is correct but B is incorrect

(4) Statement B is correct but A is incorrect

Given below is a sample of portion of DNA strand giving the base sequence on the

opposite strands. What is so, special shown in it?

5'__ GAATTC_ 3'

3' __ CTTAAG__5'

1. Deletion mutation

2. Start codon at the 5' end

3. Palindromic sequence of base pairs

4. Replication completed