How does PCR work?

Define DNA as the genetic material responsible for carrying hereditary information in living organisms, explaining its double-stranded helical structure and the role of the genetic code in determining protein synthesis.
Explain the process of DNA extraction, including the use of techniques such as chloroform and phenol, to isolate DNA from cells or tissues, emphasizing the separation of DNA from other cellular components.
Discuss the principles and applications of PCR (Polymerase Chain Reaction), including its role in DNA amplification, its various applications in fields such as diagnostics and genetic research, and the step-by-step process involving denaturation, annealing, and extension.
Explore the variations of PCR, such as quantitative PCR (qPCR) and reverse transcription PCR (rtPCR), explaining their respective uses in quantifying gene expression levels and amplifying RNA templates for gene expression analysis.
Evaluate the significance and wide-ranging applications of DNA extraction, PCR, qPCR, and rtPCR in modern molecular biology, including genetic research, forensics, diagnostics, and identifying genetic diseases or pathogens.