Final answer:
Restriction enzymes recognize specific nucleotide sequences in DNA and cut the DNA at those recognition sites, producing fragments with sticky ends or blunt ends. Sticky ends allow for the insertion of foreign DNA into a plasmid, which is then joined together using DNA ligase to form recombinant DNA.
Step-by-step explanation:
Restriction enzymes recognize specific nucleotide sequences in DNA and cut the DNA at those recognition sites. The cuts made by restriction enzymes produce fragments with either sticky ends or blunt ends, depending on the enzyme. Sticky ends have short stretches of single-stranded DNA that can hydrogen bond with complementary overhangs on another piece of DNA, allowing for the insertion of foreign DNA into a plasmid. The enzyme DNA ligase then joins the DNA fragments together to form recombinant DNA.