DNA Replication Animation

Understanding how genetic information encoded in nucleotide sequences is accurately copied during DNA replication is fundamental to molecular biology. This process ensures that genetic instructions are faithfully transmitted to daughter cells.

Watson and Crick’s Base-Pairing Model

The double-helix structure of DNA, proposed by Watson and Crick, suggested that new DNA strands are synthesized using the existing (parental) strands as templates. This mechanism allows for the precise generation of daughter strands, ensuring genetic fidelity.

DNA Replication Mechanisms

Two theoretical models were proposed :

• Conservative replication : The original parental DNA duplex remains intact, and a completely new duplex DNA molecule is formed.
• Semiconservative replication : The parental strands separate, and each serves as a template for a new complementary strand. This model was confirmed experimentally by Meselson and Stahl, demonstrating that DNA replication is semiconservative. PMID: 15608066

DNA Replication and Transcription

Both DNA replication and RNA transcription rely on the principle of template-directed synthesis, ensuring that the genetic code is preserved. While most cellular RNA and DNA molecules originate from preexisting duplex DNA, some viruses use single-stranded RNA as a template to synthesize complementary RNA or DNA strands.