Double stranded DNA virus
Any of the viruses belonging to the Class I of Baltimore classification system characterized by having a double stranded DNA as the genetic material and using a DNA-dependent DNA polymerase during replication.
Most of these viruses must enter the host nucleus before they can replicate. It is because they use the host cell's polymerases when replicating their viral genome. They can induce the cell to undergo cell division, which further leads to transformation of the cell, and ultimately, to cancer.