Why are younger people more sensitive to radiation?

• A. Their cells are developing more rapidly, making them more vulnerable.
• B. They have lower radiation uptake.
• C. Their bodies can repair faster.
• D. They have thicker skin.

Answer: (A)

The key idea is that tissues with rapidly dividing cells are more vulnerable to radiation. In developing bodies, many cells are actively proliferating to support growth and organ formation, so a larger portion of tissues are in a mitotically active state. Radiation damages DNA, and when cells are dividing, errors can be propagated more easily, leading to tissue damage and a higher risk of long-term effects like cancer. Developing tissues are also often less differentiated and may have less mature repair capabilities at certain stages, which further increases sensitivity.

The other statements don’t fit because lower radiation uptake would mean less dose reaching tissues, faster repair would reduce damage, and thicker skin would offer more protection—none explain why younger people are more sensitive.