Question

What is the primary role of reverse transcriptase in recombinant DNA technology?

• A. To synthesize DNA from an RNA template
• B. To cut DNA at specific sites
• C. To join DNA fragments
• D. To amplify DNA sequences

Hint:

Reverse transcriptase = \textbf{RNA $\rightarrow$ DNA}. Opposite of normal transcription.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Normally, transcription moves from DNA to RNA.
Reverse transcriptase is an enzyme that reverses this flow, moving from RNA back to DNA.
Step 2: Detailed Explanation:
In recombinant DNA technology, scientists often need to clone eukaryotic genes.
However, eukaryotic DNA contains introns (non-coding regions) that bacteria cannot remove.
To solve this, researchers isolate the processed mRNA (which has no introns) and use reverse transcriptase to create a DNA copy called cDNA (complementary DNA).
This cDNA can then be easily expressed in bacterial hosts.
- Option (B) describes Restriction Endonucleases.
- Option (C) describes DNA Ligase.
- Option (D) describes PCR (Polymerase Chain Reaction) using Taq Polymerase.
Step 3: Final Answer:
The primary role of reverse transcriptase is the synthesis of DNA using an RNA template.