Final answer:
Acridine orange produces null alleles by causing frameshift mutations, which disrupt the reading frame of DNA during replication, potentially leading to a complete loss of gene function.
Step-by-step explanation:
Acridine orange is known to be an effective mutagen for producing null alleles because it is an intercalating agent. These agents work by sliding between the stacked nitrogenous bases of the DNA double helix during DNA replication. The resulting distortions can cause DNA polymerase to skip nucleotides or insert extra ones, leading to frameshift mutations. Null alleles typically result from these frameshift mutations because they can cause a premature stop codon or disrupt the reading frame, leading to a complete loss of the gene product's function.