Question

Which of the following option is correct for recombinant DNA technology?

• A. Endonuclease enzyme removes nucleotides from the ends of DNA
• B. Exonuclease enzyme removes nucleotides from site within DNA
• C. Endonuclease enzyme cut long polandric DNA strand
• D. Exonuclease enzyme removes nucleotides from ends of DNA

Answer 1

The correct option is D Exonuclease enzyme removes nucleotides from ends of DNA

Restriction endonucleases recognise specific sequences in the DNA and cut the DNA into fragments. The specific sites are 4-6 bp long and are called as restriction sites. Each restriction endonuclease has a specific restriction site. Exonuclease enzymes remove nucleotides one at a time from the end of a polynucleotide chain. They shorten the DNA by one nucleotide at a time, they do not digest it into fragments. Thus the correct answer is option D.