Which group exhibits the highest radiosensitivity?

• A. Males
• B. Children
• C. Females
• D. Unborn children

Answer: (D)

Rapidly dividing, undifferentiated cells are the most vulnerable to ionizing radiation. In an embryo and developing fetus, cells are proliferating quickly and tissues are still differentiating, so radiation can disrupt development at multiple stages. This high vulnerability is described by the idea that radiosensitivity is greatest in immature, rapidly dividing cells with a long potential for division. During organ formation and fetal growth, exposure can lead to congenital anomalies, growth retardation, or even fetal loss. That’s why unborn children are the most radiosensitive group among those listed. In contrast, adults have mature tissues with slower cell turnover, making them less sensitive, and children are more sensitive than adults but still less than a developing fetus.