Which method is used to produce multiple, exact copies of a gene?

The method used to produce multiple, exact copies of a gene is cloning. Cloning refers specifically to the process of creating identical copies of a particular DNA sequence. This technique is fundamental in molecular biology and biotechnology, allowing scientists to study genes, produce proteins, or generate genetically identical organisms.

In cloning, a gene of interest is inserted into a vector, such as a plasmid, and introduced into host cells, typically bacterial or yeast cells. These host cells then replicate, producing numerous copies of the gene as they multiply. This technique is essential for applications like gene therapy, genetic engineering, and the production of recombinant proteins.

The terms duplication and replication can cause some confusion, as they are related to genetic processes. Duplication often refers to a natural or laboratory-induced process wherein a segment of DNA is copied within the genome, while replication usually pertains to the process that occurs before cell division, where the entire genome is duplicated to ensure each new cell has a complete set of DNA. However, neither of these terms specifically indicates the intentional creation of copies of a gene in the way that cloning does. Multiplication is a broader term that does not specifically address genetic processes. Thus, cloning is the most accurate term for producing multiple, exact copies of a gene.