X-Ray Certification Radiobiology 2

Question 1

What process decomposes water molecules through radiation exposure, producing free radicals that can damage DNA?

Accepted Answer

Radiolysis

Answer

Photoionization

Answer

Photodissociation

Answer

Enzymatic hydrolysis

Question 2

Approximately what percentage of radiation-induced biological damage occurs through indirect action via water radiolysis?

Accepted Answer

70–80%

Answer

10–20%

Answer

30–40%

Answer

50–60%

Question 3

What does the oxygen enhancement ratio (OER) measure in radiation biology?

Accepted Answer

Ratio of dose needed to produce the same effect in hypoxic vs. oxygenated cells

Answer

Percentage of oxygen consumed during irradiation

Answer

Number of oxygen molecules produced per ionization event

Answer

Ratio of cell survival with and without antioxidants

Question 4

Which type of radiation effect is characterized by a threshold dose, below which no observable effect occurs?

Accepted Answer

Deterministic effects

Answer

Stochastic effects

Answer

Hereditary effects

Answer

Carcinogenic effects

Question 5

Acute radiation syndrome (ARS) is best described as:

Accepted Answer

A collection of symptoms following high whole-body dose received in a short time

Answer

A chronic condition developing years after low-dose occupational exposure

Answer

Localized skin redness caused by a radiation therapy beam

Answer

Long-term genetic damage from repeated diagnostic imaging

Question 6

What is the latent period in radiation biology?

Accepted Answer

The time between exposure and the appearance of biological effects

Answer

The time radiation remains in the body before physical decay

Answer

The delay between cell division cycles caused by radiation

Answer

The period when radiation exerts its maximum ionizing effect

Question 7

Which blood cells are considered most radiosensitive and are used as biological indicators of radiation exposure?

Accepted Answer

Lymphocytes

Answer

Red blood cells (erythrocytes)

Answer

Platelets (thrombocytes)

Answer

Neutrophils (granulocytes)