Radiobiology Review

Radiobiology Exam Review I

1. What was the discovery/invention of William Crookes, Rontgen, Becquerel, and Marie

Curie in Science that was discussed in the class?

* William Crookes invented the Crookes tube.

* Roentgen discovered x-rays

* Becquerel discovered radioactivity

* Marie Curie determined radium’s atomic weight as 225

2. Inverse square law: what would happen to the radiation intensity received by you if you

increase your distance from a source of radiation 3 times.

* Decrease 9 times

3. Know the characteristics of directly ionizing and indirectly ionizing radiations. Recognize

if the following radiations are directly ionizing or indirectly ionizing:

a. X‐rays-indirectly

b. Gamma rays-indirectly

c. Alpha particles-directly

d. Electrons-directly

e. Ions-directly

f. Neutrons-indirectly

g. All charged particles-directly

4. Which macromolecule is generally believed to be the target of greatest radiobiological

importance which leads to cell death?

* DNA

5. What does LET stand for?

* Linear Energy Transfer

6. Define LET and RBE.

* LET-the energy deposited per unit distance of path travelled by the particle.

* RBE- relates to the ability of radiations with different LET ranges to produce a specific biologic response

7. Explain the basic interactions of radiation on the cells: direct and indirect actions.

* Direct action occurs when any type of radiation deposits its energy directly in the critical target resulting in ionization and excitation.

* Indirect action damages the critical site by reactive species produced by ionization elsewhere in the cell, which in turn damage the target.

Which one is the dominant process if the radiation has high LET?

* Direct action

Which one is the dominant process with X‐rays and gamma rays?

* Indirect action

8. What is one toxic agent that is created as a result of indirect action of radiation with Matter?

* Hydrogen peroxide

9. Explain elastic and inelastic scattering of...