Radiation Biology & Health Effects Flashcards
7 cards from real Radiation Health and Safety Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Radiation Biology & Health Effects flashcards as text
Which type of radiation interaction with tissue directly ionizes atoms along its path without requiring a secondary interaction?
Answer: Direct ionization by alpha particles
Alpha particles are charged particles that directly ionize atoms along their path, making them directly ionizing radiation.
The linear energy transfer (LET) of a radiation type primarily determines which biological outcome?
Answer: The density of ionizations produced along the radiation track
LET describes the energy deposited per unit length of track, which determines the density of ionizations produced along the radiation path.
Which molecule is considered the primary critical target for radiation-induced cell death?
Answer: Nuclear DNA
Nuclear DNA is the primary critical target because damage to DNA can disrupt replication and transcription, leading to cell death or mutation.
Indirect radiation damage to cells is primarily mediated by which chemical species?
Answer: Free radicals (especially hydroxyl radicals)
Indirect radiation damage occurs when radiation ionizes water molecules, producing hydroxyl radicals that then react with DNA and other biomolecules.
The oxygen enhancement ratio (OER) indicates that hypoxic tumor cells are:
Answer: Less sensitive to radiation than well-oxygenated cells
Hypoxic cells are 2–3 times less radiosensitive than well-oxygenated cells because oxygen is needed to fix (make permanent) radiation-induced free radical damage to DNA.
A somatic mutation caused by radiation exposure would most directly affect:
Answer: The exposed individual only
Somatic mutations occur in non-reproductive body cells and affect only the exposed individual; they are not inherited by offspring.
Which of the following best describes the stochastic effect of radiation exposure?
Answer: An effect whose probability increases with dose but severity does not depend on dose
Stochastic effects (e.g., cancer) have a probability that increases with dose, but once they occur, their severity is independent of the dose received.