Practice question

Intercalating agents such as proflavine and ethidium possess planar polycyclic aromatic structures that insert between stacked base pairs, extending distance between successive base pairs and unwinding helix. During replication, DNA polymerase encountering intercalator stabilized loop may slip, inserting or deleting nucleotide in repetitive runs. Resulting addition or loss of base pair disrupts triplet reading frame downstream producing frameshift mutation, rather than simple base substitution. Strong frameshift mutagenesis made acridines classic tools for studying genetic code triple nature. This principle illustrates essential molecular mechanisms governing replication fidelity and mutation fixation relevant for exam interpretation.