Which enzyme cuts DNA at specific sequences, a key tool in genetic manipulation?

Which enzyme cuts DNA at specific sequences, a key tool in genetic manipulation?

• A. Ligase
• B. Nuclease
• C. Reverse Transcriptase
• D. Restriction enzyme

Answer: (D)

Restriction enzymes cut DNA at specific sequences, which is essential for precise genetic manipulation. They recognize short, defined DNA motifs and cleave at those sites, providing predictable, site-specific breaks. This allows scientists to excise a gene of interest and insert it into a vector, or to assemble DNA fragments with compatible ends before sealing them with ligase. The other enzymes have different roles: ligase joins DNA ends, reverse transcriptase makes DNA from RNA, and nucleases can cut DNA in a non-specific or general way. The hallmark of restriction enzymes is their ability to target a particular DNA sequence and cut there, enabling controlled genetic engineering.

Restriction enzymes cut DNA at specific sequences, which is essential for precise genetic manipulation. They recognize short, defined DNA motifs and cleave at those sites, providing predictable, site-specific breaks. This allows scientists to excise a gene of interest and insert it into a vector, or to assemble DNA fragments with compatible ends before sealing them with ligase. The other enzymes have different roles: ligase joins DNA ends, reverse transcriptase makes DNA from RNA, and nucleases can cut DNA in a non-specific or general way. The hallmark of restriction enzymes is their ability to target a particular DNA sequence and cut there, enabling controlled genetic engineering.