AP BIOLOGY

Detailed explanation-1: -Restriction enzymes are also called “molecular scissors” as they cleave DNA at or near specific recognition sequences known as restriction sites. These enzymes make one incision on each of the two strands of DNA and are also called restriction endonucleases.

Detailed explanation-2: -DNA ligases are used to join the fragments of DNA generated by restriction enzymes. The availability of various types of restriction enzymes and ligases enables the transfer of specific DNA sequences from one molecule to another.

Detailed explanation-3: -The discovery of enzymes that could cut and paste DNA made genetic engineering possible. Restriction enzymes, found naturally in bacteria, can be used to cut DNA fragments at specific sequences, while another enzyme, DNA ligase, can attach or rejoin DNA fragments with complementary ends.