Genetic radiobiological effects are manifested through which mechanism?

• A. Replication of mutated nucleic acids
• B. Direct spread of mutant mitochondria
• C. Transmission of viruses
• D. Altered membrane permeability

Answer: (A)

Ionizing radiation causes changes in DNA, and those changes are carried into daughter cells when DNA is replicated. When a mutation occurs in nucleic acids, it is copied during DNA synthesis, so the mutated genetic information propagates through cell divisions. This is how genetic radiobiological effects emerge—the mutated nucleic acids are reproduced as cells divide, spreading the genetic change.

Other options describe non-genetic damage: altering membrane permeability affects membranes rather than the genetic material, and transmission of viruses or spreading mutant mitochondria isn’t the mechanism by which radiation induces heritable genetic changes.