Radiation Biology Questions and Answers with Certified Solutions

Radiation Biology Questions and Answers with Certified Solutions Which type of cells are most sensitive to radiation? Stem cells and rapidly dividing cells What is the oxygen effect in radiation biology? Oxygen enhances the damaging effects of radiation on cells What type of radiation has the highest linear energy transfer (LET)? Alpha particles How does radiation cause indirect damage to cells? By creating free radicals that attack cellular structures What is the most common biological response to low-dose radiation? Cellular repair or mutation 2 Which organ system is most affected by whole-body radiation exposure? Hematopoietic (blood-forming) system What is the main factor that determines tissue sensitivity to radiation? The rate of cell division What happens when radiation interacts with water in a cell? It produces free radicals that can damage DNA What is the law of Bergonié and Tribondeau? Cells that divide rapidly and are less specialized are more radiosensitive Which type of radiation exposure is more dangerous: acute or chronic? Acute exposure, because it delivers a high dose in a short time What is the threshold dose for deterministic effects? The minimum radiation dose required to cause predictable biological damage 3 What is the primary target of ionizing radiation in a cell? DNA What happens when radiation damages DNA beyond repair? The cell undergoes apoptosis or becomes cancerous What is the primary long-term risk of radiation exposure? Increased chance of cancer development What is the purpose of DNA repair enzymes in radiation biology? To correct radiation-induced DNA damage What is the most radiosensitive phase of the cell cycle? M phase (mitosis) Which part of the body is least sensitive to radiation? Nervous tissue