Which enzymes are known as molecular scissors in genetic engineering?

In genetic engineering, the enzymes known as 'molecular scissors' are Restriction enzymes, also specifically called restriction endonucleases. These remarkable enzymes are naturally found in bacteria, where they serve as a defense mechanism against invading viruses by cleaving foreign DNA. In biotechnology, their utility stems from their ability to recognize and cut DNA at very specific nucleotide sequences, often palindromic sequences. This precise cutting allows scientists to isolate specific genes or DNA fragments, creating 'sticky ends' or blunt ends, which are crucial for manipulating DNA. This ability to precisely excise DNA segments is fundamental for creating recombinant DNA, gene cloning, and various gene editing techniques.

• Option A, Polymerases, such as DNA polymerase, are enzymes that synthesize new DNA strands by adding nucleotides, effectively building DNA, rather than cutting it.
• Option B, Ligases, specifically DNA ligase, are enzymes that join DNA fragments together by forming phosphodiester bonds, acting as 'molecular glue' to seal breaks in DNA.
• Option D, Amylases, are enzymes that break down starch into smaller sugar molecules, playing a role in digestion, and are unrelated to cutting DNA in genetic engineering.