Cells that are least sensitive to radiation exposure include:

Cells that are least sensitive to radiation exposure include:

• A. Ova and sperm
• B. Nerve and muscle cells
• C. Blood cells
• D. Epithelial cells

Answer: (B)

Radiosensitivity is tied to how much a cell divides and how differentiated it is. Cells that are rapidly dividing or not fully specialized are more vulnerable to radiation because their DNA is being actively replicated and they have less established repair protections. Nerve and muscle cells, on the other hand, are highly specialized and mostly do not divide in adulthood. This makes them relatively resistant to radiation, since there’s little active DNA replication to disrupt and fewer vulnerable targets. Ova and sperm are germ cells that continually carry genetic information for future development, so they are quite sensitive to radiation. Blood cells come from the bone marrow, a tissue with high turnover, so those precursors are also highly sensitive. Epithelial cells lining the skin and gut divide rapidly to renew the lining, making them very radiosensitive as well. Thus, among the options, nerve and muscle cells are the least sensitive to radiation exposure.

Radiosensitivity is tied to how much a cell divides and how differentiated it is. Cells that are rapidly dividing or not fully specialized are more vulnerable to radiation because their DNA is being actively replicated and they have less established repair protections. Nerve and muscle cells, on the other hand, are highly specialized and mostly do not divide in adulthood. This makes them relatively resistant to radiation, since there’s little active DNA replication to disrupt and fewer vulnerable targets.

Ova and sperm are germ cells that continually carry genetic information for future development, so they are quite sensitive to radiation. Blood cells come from the bone marrow, a tissue with high turnover, so those precursors are also highly sensitive. Epithelial cells lining the skin and gut divide rapidly to renew the lining, making them very radiosensitive as well.

Thus, among the options, nerve and muscle cells are the least sensitive to radiation exposure.