Why isn't Nuclear DNA affected: Something to think about, why is the mitochondrial DNA (mtDNA) effected while nuclear DNA (nDNA) is not being affected. The mtDNA is most likely to be affected is because its genome is a circular DNA molecular containing about 16,000 nucleotides. On the hand, nDNA contains nearly 3 billion nucleotides which are divided into 24 linear molecules. The huge difference in genome size indicates that nDNA must be synthesizing new strands of DNA in speeds which the mtDNA can't do.

Why antiviral drugs like lamivudine work only on virus': Antiviral drugs like lamivudine are known to inhibit the replication of viral DNA. This happens because for viral DNA to be copied it has an enzyme known as reverse transcriptase. The function of that enzyme is to copy the viral RNA genome into DNA as mentioned in the abstract. Antiviral drugs come in and inhibit the viral enzyme from doing its job. Looking at bacteria they already contain their own form of DNA so they have the enzyme to replicate RNA into DNA. That is why antiviral drugs like lamivudine work only on virus'.