Fundamentals of Molecular Biology - V. I. Rezyapkin 2009

Replication

One of the most crucial Functions of Nucleic Acids (NAs) is the transmission of Genetic information from parents to offspring. This process involves the duplication, or replication, of NAs (DNA or RNA)—which serve as the custodians of genetic information—followed by its transfer to descendants. For instance, upon Cell Division, daughter Cells inherit identical DNA molecules from the mother cell, and consequently, identical genetic information. During reproduction, Viruses likewise pass exact copies of their NAs (DNA or RNA) on to progeny Viral Particles. In sexual reproduction, offspring receive genetic information from both parents. This is why children inherit traits from both mother and father.

Thus, NA replication yields daughter molecules whose nucleotide sequences are identical to one another and to the parent NA molecule. Replication can involve either DNA or RNA (in Introduction/7.html">RNA-containing Viruses). The foundation of replication is THE PRINCIPLE OF complementarity.

There are three distinct types of replication: semi-conservative, conservative, and dispersive. In semi-conservative replication, the newly synthesized NA molecule consists of one parental and one newly synthesized polynucleotide strand. In conservative replication, the newly formed NA molecule is composed entirely of daughter polynucleotide sequences, whereas in dispersive replication, the newly synthesized NA strand is made up of alternating fragments of parental and daughter sequences.

PROKARYOTES AND EUKARYOTES both exhibit the semi-conservative type of replication. Viruses utilize all Three types of replication. Below, we will examine the replication processes in prokaryotes and eukaryotes in greater detail. Viral replication is covered in the section «Organization OF THE Viral Genome».