AP BIOLOGY

Detailed explanation-1: -Restriction enzymes are DNA-cutting enzymes. Each enzyme recognizes one or a few target sequences and cuts DNA at or near those sequences. Many restriction enzymes make staggered cuts, producing ends with single-stranded DNA overhangs. However, some produce blunt ends.

Detailed explanation-2: -Restriction Enzyme 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-3: -If genomic DNA is isolated from one organism and cut with one particular restriction enzyme, a specific set of fragments can be separated and identified by electrophoresis. If DNA from a different organism is cut by the same restriction enzyme, a different set of fragments will be generated.

Detailed explanation-4: -In gene cloning, one uses a restriction endonuclease to cut open the circular plasmid DNA in a region of the plasmid not necessary for replication (see Figure 2-3). Suppose, for example, that the enzyme EcoRI cuts open the plasmid in such a nonessential area.

Detailed explanation-5: -The restriction enzymes generate two different types of cuts. Blunt ends are produced when they cut the DNA at the centre of the recognition sequence, and sticky ends produce an overhang.