Which characteristic tends to increase cellular radiosensitivity?

Which characteristic tends to increase cellular radiosensitivity?

• A. Are young & growing
• B. Are old and non-replicating
• C. Are highly differentiated
• D. Are large in size

Answer: (A)

Radiosensitivity tracks how actively a cell is growing and dividing. Young, growing cells have a high mitotic rate and are less differentiated, so they spend more time in cycles where DNA is being replicated and checked for damage. Radiation tends to cause DNA breaks, and cells with high replication activity have a higher chance of lethal misrepair or failure to complete division, leading to cell death. That’s why these cells are more susceptible. Old, non-replicating cells aren’t hopping through division as much, so they’re more capable of surviving radiation. Highly differentiated cells are specialized and less prone to division, which also makes them less sensitive. Size isn’t a strong predictor of radiosensitivity.

Radiosensitivity tracks how actively a cell is growing and dividing. Young, growing cells have a high mitotic rate and are less differentiated, so they spend more time in cycles where DNA is being replicated and checked for damage. Radiation tends to cause DNA breaks, and cells with high replication activity have a higher chance of lethal misrepair or failure to complete division, leading to cell death. That’s why these cells are more susceptible.

Old, non-replicating cells aren’t hopping through division as much, so they’re more capable of surviving radiation. Highly differentiated cells are specialized and less prone to division, which also makes them less sensitive. Size isn’t a strong predictor of radiosensitivity.