Which of the following cell types are least sensitive to ionizing radiation damage?

• A. Hematopoietic stem cells
• B. Epithelial cells
• C. Lymphocytes
• D. Neurons

Answer: (D)

Verified step by step guidance

1. Understand the concept of ionizing radiation: Ionizing radiation damages cells by causing DNA breaks and other molecular disruptions. Sensitivity to radiation varies among cell types based on their ability to repair DNA and their rate of division.
2. Review the characteristics of the cell types listed: Hematopoietic stem cells, epithelial cells, and lymphocytes are all rapidly dividing cells, which makes them more sensitive to ionizing radiation. Neurons, on the other hand, are non-dividing cells and have mechanisms to resist radiation damage.
3. Consider the role of cell division: Cells that divide frequently, such as hematopoietic stem cells, epithelial cells, and lymphocytes, are more prone to radiation damage because their DNA is actively being replicated, making it more vulnerable to breaks.
4. Analyze the repair mechanisms: Neurons, being non-dividing and highly specialized cells, have robust DNA repair mechanisms and are less likely to be affected by ionizing radiation compared to rapidly dividing cells.
5. Conclude based on biological principles: Neurons are the least sensitive to ionizing radiation damage due to their non-dividing nature and efficient DNA repair systems, while the other cell types are more sensitive due to their high rates of division.