Question

The DNA ligase enzyme that is frequently used to ligate different DNA fragments in order to generate rDNA molecules is isolated from:

• A. T2 Bacteriophage
• B. T4 Bacteriophage
• C. Lambda Bacteriophage
• D. M13 filamentous phage

Answer 1

The Correct Option is B

DNA ligase is a key enzyme used in recombinant DNA technology for joining DNA fragments by forming phosphodiester bonds. The enzyme most widely used in labs is derived from the T4 bacteriophage.

• T4 Bacteriophage: Produces T4 DNA ligase, which is highly effective in joining both sticky and blunt ends of DNA fragments. It is the standard enzyme used in genetic engineering for constructing recombinant DNA molecules.
• T2 Bacteriophage: Though similar in nature, it is not the source of the commonly used DNA ligase.
• Lambda Bacteriophage: Used as a cloning vector in molecular biology, but not the source of DNA ligase.
• M13 Filamentous Phage: Important in sequencing and cloning vectors but does not provide the ligase enzyme.

Thus, the correct and most suitable answer is (B) T4 Bacteriophage.