Author: Ms. Pushplata Kanwar
Volume: 01
First Online: 2026
Pages: 74-140
DOI:

This chapter provides a comprehensive overview of the central dogma of molecular biology and the mechanisms of DNA replication, emphasizing the flow of genetic information from DNA to RNA and ultimately to proteins. It explains the processes of transcription, translation, and reverse transcription, highlighting their biological significance. The chapter further discusses epigenetic regulation through DNA methylation and DNA–protein interactions, including chromatin remodeling, genomic imprinting, X-chromosome inactivation, and histone modifications involved in gene expression. A detailed description of DNA replication is presented, covering the semiconservative model, replication enzymes, replication fork dynamics, leading and lagging strand synthesis, proofreading, and DNA repair mechanisms. The replication of plasmid DNA, genomic DNA, centromeric DNA, and telomeric DNA is also described, along with the role of telomerase in maintaining chromosome integrity. In addition, the chapter explains DNA damage, repair pathways, cell cycle regulation, replication fidelity, and the clinical significance of defects in DNA replication and genome maintenance. Overall, the chapter provides a strong foundation for understanding the molecular basis of
heredity, genome stability, gene regulation, and modern molecular biology.