AP BIOLOGY

Detailed explanation-1: -Restriction enzymes are found in bacteria (and other prokaryotes). They recognize and bind to specific sequences of DNA, called restriction sites.

Detailed explanation-2: -Restriction enzymes are isolated from the prokaryotes.

Detailed explanation-3: -Definition. A restriction enzyme is a protein isolated from bacteria that cleaves DNA sequences at sequence-specific sites, producing DNA fragments with a known sequence at each end.

Detailed explanation-4: -Restriction enzymes are a group of proteins that bacteria produce to cut up the DNA of invading viruses. Electron micrograph of Escherichia coli, close-up. Such bacteria are an important source for restriction enzymes.

Detailed explanation-5: -Therefore, when it is digested by a restriction enzyme, several smaller DNA fragments-called restriction fragments-are produced. Example of restriction enzymes includes EcoRI and smaI.