Question

Which of the following tools of recombinant $DNA$ technology is incorrectly paired with its use?

• A. EcoRI - Production of sticky ends
• B. $DNA$ ligase - Multiplication of $rDNA$ molecules
• C. ori- copy number
• D. Selectable marker - Identification of transformants

Answer 1

Answer: (B)

$DNA$ ligase - Multiplication of $rDNA$ molecules

Answer 2

$DNA$ ligases are also called genetic gum. They join two individual fragments of double stranded $DNA$ by forming phosphodiester bonds between them thus help in sealing of $DNA$ fragments. Therefore acts as molecular glue. The enzyme used most often is $T_4\, DNA$ ligase.