Polymerase Chain Reaction (PCR) is a technique used to amplify or make copies of DNA. It is an essential tool in molecular biology and is widely used in various fields such as genetics, forensic science, and medical diagnostics.

Option 1: DNA using living cells

This option is correct. PCR can be performed using DNA extracted from living cells. It involves a series of temperature-dependent DNA synthesis reactions that are carried out in a test tube. PCR requires a DNA template, which is usually extracted from cells. The DNA template is mixed with DNA primers, nucleotides, and DNA polymerase. The reaction mixture is subjected to multiple cycles of heating and cooling, which allows the DNA to denature, anneal the primers, and then extend the DNA strand using the DNA polymerase. This process allows for the amplification and production of a large number of copies of the DNA of interest.

Option 2: DNA without using living cells

This option is incorrect. PCR does not require living cells for the amplification of DNA. It can be performed using DNA extracted from cells that are no longer viable or from other sources.

Option 3: RNA using living cells

This option is incorrect. PCR is not used for amplifying RNA using living cells. PCR