Quiz 3

Which of the following is (are) considered low-LET radiation(s)? 1. X-rays 2. Alpha particles 3. Gamma rays a. 1 and 3 only b. 2 only c. 1 only d. 2 and 3 only

a. 1 and 3 only

Which of the following are major tasks of the cytoplasm? 1. Accepts and builds up unrefined materials and assembles from these materials new substances such as carbohydrates, lipids, and proteins. 2. Breaks down organic materials to produce energy. 3. Packages substances for distribution to other areas of the cell or to various sites in the body through the circulation. 4. Eliminates waste products. a. 1, 2, 3, and 4 b. 2, 3, and 4 only c. 1, 3, and 4 only d. 1, 2, and 3 only

a. 1, 2, 3, and 4

Which of the following requirements must be met before nuclear particles such as protons or neutrons are considered to be ionizing radiation? 1. They are in motion 2. Reside in a radioactive atom 3. Are unpaired 4. Have sufficient kinetic energy a. 1, 4 b. 1, 3, 4 c. none of the above d. 2, 3

a. 1, 4

A biologic reaction is produced by 5 Gy of a test radiation. It takes 25 Gy of 250 kVp x-radiation to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation? a. 5 b. 10 c. 12.5 d. 0.5

a. 5 ?

Alpha particles are more penetrating than beta particles. a. False b. True

a. False

Indirect actions comprise only a small percentage of the interactions of ionizing radiation within cells. a. False b. True

a. False

Radiosensitivity increases with increasing hypoxia. a. False b. True

a. False?

What is any chemical reaction in which atoms lose electrons called? a. Oxidation b. Osmosis c. Metabolism d. Synthesis

a. Oxidation

The amount of energy transferred to electrons by ionizing radiation is the basis of the concept of: a. Radiation dose b. Electromagnetic radiation c. Radioactive decay d. Nuclear power

a. Radiation dose

Which of the following is an example of a low LET radiation? a. X-rays b. Alpha particles c. Neutrons d. All of the above

a. X-rays

The _____ is the least penetrating form of ionizing radiation. a. alpha particle b. x-ray c. beta particle d. gamma ray

a. alpha particle

LET is measured in: a. keV/µm b. keV/rad c. Gray d. rem

a. keV/µm

The only difference between x-rays and gamma rays is their ______. a. origin b. name c. energy d. size

a. origin

The steps, or rungs, of the DNA ladder-like structure consist of complementary chemicals that are a. pairs of nitrogenous bases. b. sugar-phosphate compounds. c. acetic acids. d. fatty acids.

a. pairs of nitrogenous bases.

Which of the following types of radiation will travel farthest in biologic tissue? a. x-radiation b. neutrons c. beta d. alpha

a. x-radiation ?

What charge does a beta particle have? a. +1 b. -1 c. no charge d. A or B

b. -1

What is the effect on relative biologic effectiveness (RBE) as linear energy transfer (LET) increases? a. As LET increases, RBE stabilizes b. As LET increases, RBE increases c. LET has no effect on RBE d. As LET increases, RBE decreases

b. As LET increases, RBE increases

Which of the following effects can be defined as any type of radiation that deposits its energy directly in the critical target? a. Isotonic effect b. Direct action c. Indirect action d. Radiolysis

b. Direct action

When water is irradiated, what are the products of the initial interaction? a. HOH+ and e- b. OH* and e- c. H2O2 d. H2O and e-

b. OH* and e-

Alpha particles have two protons and two neutrons and are considered to be particulate radiation. a. False b. True

b. True ?

The principle damaging product of water radiolysis is: a. Alpha particles b. Water radiolysis is not damaging to cells c. X-ray d. The toxic effect of hydrogen peroxide and hydroperoxyl on the cells

b. Water radiolysis is not damaging to cells?

As LET increases, the ability of ionizing radiation to cause biologic effects: a. remains constant, not increasing or decreasing b. also generally increases until it reaches a maximal value c. decreases considerably d. decreases slightly

b. also generally increases until it reaches a maximal value

Direct action may occur after exposure to any type of radiation, but it is much more likely to happen after exposure to: a. low-LET radiation such as gamma rays b. high-LET radiation such as alpha particles c. low-LET radiation such as x-rays d. nonionizing radiation such as microwaves

b. high-LET radiation such as alpha particles ?

Which of the following are types of ionizing radiation that produce virtually the same biologic effect from equal absorbed doses in body tissue? a. x-rays, alpha particles, fast neutrons b. x-rays, beta particles, gamma rays c. x-rays, neutrons, gamma rays d. alpha particles, beta particles, gamma rays

b. x-rays, beta particles, gamma rays

What charge does an alpha particle have? a. -1 b. +1 c. +2 d. no charge

c. +2

In general, which of the following can human cells do? 1. Move, grow, react, and protect themselves 2. Repair damage and regulate life processes 3. Reproduce a. 2 and 3 only b. 1 and 2 only c. 1, 2, and 3 d. 1 and 3 only

c. 1, 2, and 3

What is a highly coiled strand that is one of two duplicated portions of DNA in a replicated chromosome that appears during cell division identified as? a. A centromere b. A centrosome c. A chromatid d. A curl

c. A chromatid

OH* + OH* = __________. a. HOH- b. HOH+ c. H2O2 d. H2O

c. H2O2

The term that compares the response of cells to radiation in the presence or absence of oxygen is called the: a. Oxygen dose curve b. Oxygen tension c. Oxygen Enhancement Ratio d. Radiosensitizer effect

c. Oxygen Enhancement Ratio

Biologic material is most sensitive to low LET radiation under which of the following conditions? a. Deoxygenated b. Hypoxic c. Oxygenated d. Anoxic

c. Oxygenated

During which of the following subphases of mitosis do the centrioles migrate to opposite sides of the cell and begin to regulate the formation of the mitotic spindle? a. Metaphase b. Telophase c. Prophase d. Anaphase

c. Prophase

Which molecules in the human body are most commonly directly acted on by ionizing radiation to produce molecular damage through indirect action? a. Carbohydrate b. Protein c. Water d. Fat

c. Water

During beta emission, an atom releases _____. a. x-ray photons b. positrons c. electrons d. neutrons

c. electrons

Beta particles are actually a. x-rays b. protons c. high-speed electrons d. gamma rays

c. high-speed electrons

If oxygen is present during high-LET radiation the effect of radiation is______? a. maximal b. reduced c. the same d. minimal

c. the same

The characteristics of high LET radiations include: 1. Large mass 2. Carry a charge 3. Travel fast 4. Sparsely ionizing 5. More likely to interact with tissue via direct effect a. 3, 4, 5 b. 2, 3, 4 c. 1, 2, 3 d. 1, 2, 5

d. 1, 2, 5

How much energy can an alpha particle have? a. 50-150 keV b. 50-150 MeV c. 20-200 eV d. 4-7 MeV

d. 4-7 MeV

Free radicals: a. Can produce point lesions b. Have excess energy that can be transferred to other molecules c. Can interact at a distant site d. All of the above

d. All of the above

During what phase of mitosis are the centromeres severed followed by the sister chromatids moving apart and are then subsequently pulled toward opposite poles of the mitotic spindle? a. Prophase b. Metaphase c. Telophase d. Anaphase

d. Anaphase

While passing through a human cell, an x-ray photon interacts with and inactivates the cell's master molecule. What is the consequence for the cell? a. Increased pressure on the cell membrane leading to immediate rupture b. Disruption of cell chemistry only c. Loss of all intracellular fluid d. Death

d. Death

Which of the following serves as a prototype for messenger RNA (mRNA)? a. Transfer RNA (tRNA) b. Nitric acid (HNO3) c. Potassium (K) and sodium (Na) d. Deoxyribonucleic acid (DNA)

d. Deoxyribonucleic acid (DNA)

Which action of ionizing radiation is most harmful to the human body, due to the irreversible damage it causes? a. Direct action b. Mitotic action c. Molecular action d. Indirect action

d. Indirect action?

During mitosis, which phase of the cellular life cycle is the actual DNA synthesis period? a. M b. G2 c. G1 d. S

d. S

Which of the following are products of radioactive decay? a. gamma photons b. alpha particles c. beta particles d. all of the above

d. all of the above

What charge does an x-ray photon have? a. +1 b. -1 c. +2 d. no charge

d. no charge