Which of the following cells is most affected by radiation due to rapid division?

The choice of blood cells as the most affected by radiation due to rapid division is accurate primarily because blood cells, particularly those in the bone marrow such as hematopoietic stem cells, undergo frequent mitotic cycles. These cells are continually being produced to replenish the blood supply—this includes red blood cells, white blood cells, and platelets.

During the process of division, the DNA in these rapidly dividing cells is vulnerable to damage from ionizing radiation. This damage can result in mutations, apoptosis, or impaired cell function, leading to significant consequences such as anemia (from red blood cell loss), compromised immune response (from white blood cell loss), or issues with clotting (from platelet loss).

In contrast, muscle cells and nerve cells are generally considered more radio-resistant. Muscle cells typically do not undergo rapid division, and nerve cells, once fully developed, do not divide at all under normal circumstances. Fat cells also have a slower turnover rate compared to blood cells, making them less susceptible to the effects of radiation. This highlights the unique vulnerability of hematopoietic cells in the context of radiation exposure.