Chapter 6
The term “apoptosis” is synonymous with:
programmed cell death
meiosis
mitosis
point mutation
programmed cell death
Which of the following gonadal radiation doses may cause permanent sterility in a human male?
0.01 Gy
1.0 Gy
2.0 Gy
6.0 Gy
6.0 Gy
Direct action may occur after exposure to any type of radiation, but it is much more likely to happen after exposure to:
low-LET radiation such as x-rays
low-LET radiation such as gamma rays
high-LET radiation such as alpha particles
nonionizing radiation such as microwaves
high-LET radiation such as alpha particles
If bone marrow cells have not been destroyed by exposure to ionizing radiation, they can:
become insensitive to future exposures from ionizing radiation
overpopulate and become radioresistant
remain in circulating blood indefinitely
repopulate after a period of recovery
repopulate after a period of recovery
Neutrophils play an important role in:
circulating blood through the human body
clotting blood
fighting infection
preventing hemorrhage
fighting infection
Which of the following means the loss or change of a nitrogenous base in the DNA chain?
Aneuploidy
Bleb
Free radical
Mutation
Mutation
Which of the following illustrates the radiation sensitivity of a particular type of cell?
Epidemiologic data curve
Extrapolation curve
Dose-response curve
Survival curve
Survival curve
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?
Loss of all intracellular fluid
Increased pressure on the cell membrane leading to immediate rupture
Disruption of cell chemistry only
Death
Death
_____ of the effects of x-radiation and gamma in macromolecules of living systems (in vivo) occur as a result of indirect action.
None
Very few
Some
Most
Most
As LET increases, the ability of ionizing radiation to cause biologic effects:
also generally increases until it reaches a maximal value
decreases considerably
decreases slightly
remains constant, not increasing or decreasing
also generally increases until it reaches a maximal value
Which of the following statements is true concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest x-ray?
Patients are expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
Patients are expected to sustain some damage to either the blood or the blood-forming organs as a consequence of the examination.
Patients are expected to sustain total damage to either the blood or the blood-forming organs as a consequence of the examination resulting in fatality.
Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
Which of the following is a scavenger-type of white blood cell that fights bacteria?
Granulocytes
Lymphocytes
Neutrophils
Thrombocytes
Granulocytes
The radiation dose required to produce mitotic death is:
less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells
more than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells
the same as the dose needed to produce apoptosis in slowly dividing cells or nondividing cells
nonexistent as mitotic death cannot be produced in slowly dividing cells or nondividing cells by ionizing radiation
less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells
Which of the following groups of cells is most radiosensitive?
Lymphocytes
Adult nerve cells
Erythrocytes
Muscle cells
Lymphocytes
Which of the following groups of cells is least radiosensitive?
Adult nerve cells
Nerve cells in the embryo-fetus
Lymphocytes
Immature spermatogonia
Adult nerve cells
A periodic blood count is not recommended as a method for monitoring occupational radiation exposure because:
1. biologic damage from ionizing radiation cannot be determined from a blood test
2. biologic damage has already been sustained when an irregularity is seen in the blood count
3. a traditional blood count is a relatively insensitive test that is unable to indicate exposures of less than 10 cGy (10 rads)
1 only
2 only
3 only
2 and 3 only
2 and 3 only
Based on current data, which of the following would be considered a safe radiation dose for the gonads of both males and females?
5 Gy
3 Gy
1 Gy
0 Gy
0 Gy
A biologic reaction is produced by 4 Gy (400 rad) of a test radiation. It takes 16 Gy (1600 rad) of 250-kVp x-rays to produce the same biologic reaction. What is the relative biologic effectiveness (RBE) of the test radiation?
2
4
8
12
4
Radiosensitivity of ova:
remains constant throughout the lifetime of the germ cell
varies considerably throughout the lifetime of the germ cell
varies slightly throughout the lifetime of the germ cell
is insignificant because the germ cell is not radiosensitive
varies considerably throughout the lifetime of the germ cell
One micron (mm) = _____ m.
10–6
10+6
10–3
10+3
10–6
Which of the following humans is most radiosensitive?
A mature adult
The embryo-fetus during the first trimester of pregnancy
The fetus during the third trimester of gestation
A 5-year-old child
The embryo-fetus during the first trimester of pregnancy
Which of the following is (are) considered low-LET radiation(s)?
1. X-rays
2. Alpha particles
3. Gamma rays
1 only
2 only
1 and 3 only
2 and 3 only
1 and 3 only
The normal white blood cell count for an adult ranges from _____ to _____/mm3 of blood.
1000; 5000
3000; 6000
5000; 10,000
7000; 15,000
5000; 10,000
Which of the following tissues contain cells that do not divide?
1. Epithelial tissue
2. Muscle tissue
3. Nervous tissue in the adult
1 and 2 only
1 and 3 only
2 and 3 only
1, 2, and 3
2 and 3 only
OH* + OH* = __________.
H2O
HOH+
HOH–
H2O2
H2O2