Final answer:
The Polymerase Chain Reaction (PCR) is the genetic engineering tool used to make multiple copies of DNA. It's a rapid and efficient method essential for various applications in sciences, such as research and forensics.
Step-by-step explanation:
The tool used in genetic engineering to make multiple copies of DNA is the Polymerase Chain Reaction (PCR). PCR is a biotechnological method that creates many identical copies of specific DNA sequences rapidly. This process is essential for various applications in research, forensic analysis, clinical diagnostics, and more. PCR amplifies DNA by cycling through three main steps: denaturing (heating the DNA to separate strands), annealing (cooling to allow primers to attach to the single-stranded DNA), and extension (the DNA polymerase synthesizes the new DNA strand). These cycles are repeated multiple times to achieve a large number of DNA copies from a small initial sample.
On the other hand, other tools such as restriction enzymes are used to cleave specific DNA sequences, gel electrophoresis is employed to separate DNA fragments based on size, and DNA sequencing is the process used to determine the exact sequence of nucleotides within a DNA molecule.