DNA mediate the function of the genome. Genomic DNA is tightly and orderly packed in the process called DNA condensation, to fit the small available volumes of the cell. In eukaryotes, DNA is located in the cell nucleus, with small amounts in mitochondria and chloroplasts. In prokaryotes, the DNA is held within an irregularly shaped body in the cytoplasm called the nucleoid. The genetic information in a genome is held within genes, and the complete set of this information in an organism is called its genotype. A gene is a unit of heredity and is a region of DNA that influences
DNA re-replication DNA re-replication DNA re-replication (or simply rereplication) is an undesirable and possibly fatal occurrence in eukaryotic cells in which the genome is replicated more than once per cell cycle. Rereplication is believed to lead to genomic instability and has been implicated in the pathologies of a variety of human cancers. To prevent rereplication, eukaryotic cells have evolved multiple, overlapping mechanisms to inhibit chromosomal DNA from being partially or fully rereplicated in a given cell cycle. These control mechanisms rely on cyclin-dependent kinase (CDK) activity. DNA replication control mechanisms cooperate to prevent the relicensing of replication origins and to activate cell