Final answer:
Ionizing radiation affects biological tissues by interacting with DNA, leading to both negative effects, like cancer, and therapeutic uses in medicine. Therapeutic ultrasound is used to generate heat for treatment purposes, while the efficacy of magnetic fields in health products lacks clinical verification.
Step-by-step explanation:
The effects of ionizing radiation on biological tissue, including therapeutic uses like in cancer treatment, can be largely attributed to its interaction with cellular molecules, particularly DNA. Radiation has the ability to interfere with cell reproduction and destroy cell functions, which underpins its utility in medical applications. Ultrasound (therapeutic US) can generate localized heating in tissues for purposes such as physical therapy and facilitating the breakdown of kidney stones. In contrast, the effects of magnetic fields and products like magnetic bracelets or mattresses have not been clinically verified to deliver health benefits, and their mechanisms of action remain unexplained.