This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
The most radiosensitive tissue is: March 2011 
Select and explain. 
A. Nerve, B. Bone marrow, C. Thyroid, D. Liver
B: Bone marrow
Answer: B: Bone marrow 
Explanation: Ans. B: Bone marrow Bone is among the most radioresistant organ By contrast, the male testis, female ovary, and bone marrow are the most sensitive organs Most Radiosensitive: Phase of cell cycle: G2M phase Structure in cell: DNA Cell: Lymphocyte Lung tumour: Small cell Ca Brain tumour: Medulloblastoma Ovarian tumour: Dysgerminoma Testicular tumour: Seminoma Bone tumour: Ewing's sarcoma Radioresistance: Cailage is radioresistant structure