The general name for taking a piece of one DNA, and combining it with another strand of DNA. Used to produce once rare medicinal proteins and hormones as well as vaccines.

• A. Cloning
• B. Epigenetics
• C. Genetic testing
• D. Recombinant DNA

Answer: (D)

Recombinant DNA is the process of joining DNA fragments from two different sources to form a single, new molecule. This is usually done by cutting DNA with restriction enzymes and sealing fragments into a vector like a plasmid, which can then be introduced into host cells to produce the desired protein. This approach enables manufacturing medicinal proteins and hormones that are scarce or difficult to obtain otherwise, and it underpins many vaccines. Cloning refers to making copies of DNA or organisms, not mixing pieces from different sources. Epigenetics deals with changes in gene activity without altering the DNA sequence, and genetic testing analyzes DNA for mutations or traits rather than creating new DNA combinations.