Which tissue is most likely to develop cancer from exposure to equal doses of ionizing radiation?

Which tissue is most likely to develop cancer from exposure to equal doses of ionizing radiation?

• A. Dermis
• B. Bone Marrow
• C. Cortical Bone
• D. Spinal Cord

Answer: (B)

A key idea here is that tissues with cells that divide rapidly and contain many stem cells are most vulnerable to radiation-induced cancer. Ionizing radiation damages DNA, and cancer can arise when those DNA changes persist in cells that retain the ability to proliferate. Bone marrow fits this vulnerability best because it is full of hematopoietic stem cells that divide continuously to produce blood cells. When exposed to radiation, these actively dividing cells accumulate mutations more readily, increasing the risk of malignant transformation, commonly leading to leukemia. The other tissues are less susceptible for this specific effect. Dermis contains skin cells that do divide, but not at the same high rate as bone marrow and not as prone to leukemias from equal radiation doses. Cortical bone is dense and has relatively few living, actively dividing cells. The spinal cord comprises mostly mature nerve tissue with low cell turnover, making it comparatively resistant to radiation-induced cancer at equal doses. So, the tissue most likely to develop cancer from equal radiation exposure is the bone marrow because its constantly renewing, highly proliferative cell population is most prone to radiation-driven genetic damage that can lead to cancer.

A key idea here is that tissues with cells that divide rapidly and contain many stem cells are most vulnerable to radiation-induced cancer. Ionizing radiation damages DNA, and cancer can arise when those DNA changes persist in cells that retain the ability to proliferate.

Bone marrow fits this vulnerability best because it is full of hematopoietic stem cells that divide continuously to produce blood cells. When exposed to radiation, these actively dividing cells accumulate mutations more readily, increasing the risk of malignant transformation, commonly leading to leukemia.

The other tissues are less susceptible for this specific effect. Dermis contains skin cells that do divide, but not at the same high rate as bone marrow and not as prone to leukemias from equal radiation doses. Cortical bone is dense and has relatively few living, actively dividing cells. The spinal cord comprises mostly mature nerve tissue with low cell turnover, making it comparatively resistant to radiation-induced cancer at equal doses.

So, the tissue most likely to develop cancer from equal radiation exposure is the bone marrow because its constantly renewing, highly proliferative cell population is most prone to radiation-driven genetic damage that can lead to cancer.