The first type II restriction endonuclease discovered that could cut dsDNA specific site was:

1. EcoRI

2. SmaI

3. Hind II

4. Hind III

Which statement regarding restriction endonucleases is NOT correct?

1. They recognize a specific base sequence in the DNA.

2. They are produced by bacterial cells as a primitive immune system.

3. They digest DNA by removing nucleotides from a free 3' end.

4. They often generate stick ends.

A foreign DNA and plasmid cut by the same restriction endonuclease can be joined to form a recombinant plasmid using

(1) Eco RI                       

(2) taq polymerase

(3) polymerase III           

(4) ligase

Which of the following restriction enzymes produces blunt ends?

(1) Sal I                           

(2) Eco RV

(3) Xho                           

(4) Hind III

Which of the following is a endonuclease?

(1) Protease

(2) DNase I

(3) RNase restriction

(4) Hind II

The cutting of DNA at specific locations became possible with the discovery of 

(1) restriction enzymes

(2) probes

(3) selectable markets

(4) ligases

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

There is a restriction endonuclease called Eco RI. What does 'co' part in it stand for?

1. Coelom                         

2. Coenzyme

3. coli                               

4. Colon

Which one of the following palindromic base sequences in DNA can be easily cut at about

the middle by some particular restriction enzyme?

1. 5'$-$CGTTCG$-$3'

     3'$-$ATGGTA$-$-5'

2. 5'$-$GATATG$-$3'

     3'$-$CTACTA$-$5'

3. 5'$-$GAATTC$-$3'

     3'$-$CTTAAG$-$5'

4. 5'$-$CACGTA$-$3'

     3'$-$CTCAGT$-$5'

Restriction endonucleases are enzymes which

1. make cuts at specific positions within the DNA molecule

2. recognize a specific nucleotide sequence for binding of DNA ligase

3. restrict the action of the enzyme DNA polymerase

4. remove nucleotides from the ends of the DNA molecule