Which of the following enzymes catalyse the removal of nucleotides from the ends of DNA?
1. endonuclease
2. exonuclease
3. DNA ligase
4. Hind - Il
‘Restriction’ in restriction enzyme refers to
1. | cleaving of phosphodiester bond in DNA by the enzyme |
2. | cutting of DNA at specific position only |
3. | prevention of the multiplication of bacteriophage by the host bacteria |
4. | All of the above |
Which of the following statements does not hold true for restriction enzymes?
1. | It recognises a palindromic nucleotide sequence |
2. | It is an endonuclease |
3. | It is isolated from viruses |
4. | It produces the same kind of sticky ends in different DNA molecules |