Radiation can

• A. affect body tissues and cells that can carry hereditary materials for future generations
• B. only cause skin reddening
• C. improve enamel strength
• D. have no biological effect

Answer: (A)

Radiation can affect tissues at the cellular level, including DNA in cells that carry hereditary information. When ionizing radiation damages DNA in germ cells (sperm or ova), those mutations can be passed on to future generations, which is why hereditary effects are a key concern. This is why the statement about radiation affecting tissues and cells that carry hereditary material is the best answer. The other options aren’t correct: skin reddening is not the only possible effect and is more a high-dose consequence; radiation does not improve enamel strength; and radiation can have biological effects even at the low doses used in dental imaging.