Deck 7: Molecular and Cellular Radiation Biology

Question 1

_________ of the effects of x-radiation and gamma in macromolecules of living systems (in vivo) occur as a result of indirect action.

A)None
B)Very few
C)Some
D)Most

Answer 1

Most

Question 2

One micron (mm) = __________.

A)10-⁶ m
B)10+⁶ m
C)10-³ m
D)10+³ m

Answer 2

10-⁶ m

Question 3

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 x-rays.
B)low-LET radiation such as gamma rays.
C)high-LET radiation such as alpha particles.
D)nonionizing radiation such as microwaves.

Answer 3

high-LET radiation such as alpha particles.

Question 4

Which of the following curves illustrates the radiation sensitivity of a particular type of cell?

A)Epidemiologic data curve
B)Extrapolation curve
C)Dose-response curve
D)Survival curve

Question 5

The term apoptosis is synonymous with:

A)programmed cell death.
B)meiosis.
C)mitosis.
D)point mutation.

Question 6

Which of the following humans is most radiosensitive?

A)A mature adult
B)An embryo or fetus during the first trimester of pregnancy
C)A fetus during the third trimester of gestation
D)A 5-year-old child

Question 7

Which of the following groups of cells is least radiosensitive?

A)Adult nerve cells
B)Nerve cells in an embryo or fetus
C)Lymphocytes
D)Immature spermatogonia

Question 8

OH* + OH* = __________.

A)H₂O
B)HOH+
C)HOH-
D)H₂O₂

Question 9

A biologic reaction is produced by 4 Gyt of a test radiation.It takes 16 Gyt of 250-kVp x-rays to produce the same biologic reaction.What is the relative biologic effectiveness (RBE) of the test radiation?

A)2
B)4
C)8
D)12

Question 10

As LET increases,the ability of ionizing radiation to cause biologic effects:

A)also generally increases until it reaches a maximal value.
B)decreases considerably.
C)decreases slightly.
D)remains constant,not increasing or decreasing.

Question 11

Which of the following means the loss or change of a nitrogenous base in the DNA chain?

A)Aneuploidy
B)Bleb
C)Free radical
D)Mutation

Question 12

The normal white blood cell count for an adult ranges from:

A)1000 to 5000/mm3 of blood.
B)3000 to 6000/mm3 of blood.
C)5000 to 10,000/mm3 of blood.
D)7000 to 15,000/mm3 of blood.

Question 13

Which of the following statements is true concerning patients who receive radiation exposure from a routine radiographic procedure such as a chest x-ray?

A)Patients are expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
B)Patients are not expected to sustain appreciable damage to either the blood or the blood-forming organs as a consequence of the examination.
C)Patients are expected to sustain some damage to either the blood or the blood-forming organs as a consequence of the examination.
D)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.

Question 14

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)Loss of all intracellular fluid
B)Increased pressure on the cell membrane leading to immediate rupture
C)Disruption of cell chemistry only
D)Death

Question 15

Based on current data,which of the following would be considered a safe radiation dose for the gonads of both males and females?

A)5 Gyt
B)3 Gyt
C)1 Gyt
D)0 Gyt

Question 16

Which of the following groups of cells is most radiosensitive?

A)Lymphocytes
B)Adult nerve cells
C)Erythrocytes
D)Muscle cells

Question 17

Which of the following gonadal radiation doses may cause permanent sterility in a male human?

A)0.01 Gyt
B)1.0 Gyt
C)2.0 Gyt
D)6.0 Gyt

Question 18

Which of the following is/are considered low-LET radiation(s)?
1)X-rays
2)Alpha particles
3)Gamma rays

A)1 only
B)2 only
C)1 and 3 only
D)2 and 3 only

Question 19

The radiation dose required to produce mitotic death is:

A)less than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells.
B)more than the dose needed to produce apoptosis in slowly dividing cells or nondividing cells.
C)the same as the dose needed to produce apoptosis in slowly dividing cells or nondividing cells.
D)nonexistent as mitotic death cannot be produced in slowly dividing cells or nondividing cells by ionizing radiation.

Question 20

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.

A)1 only
B)2 only
C)3 only
D)2 and 3 only

Question 21

The radiosensitivity of ova:

A)remains constant throughout the lifetime of the germ cell.
B)varies considerably throughout the lifetime of the germ cell.
C)varies slightly throughout the lifetime of the germ cell.
D)is insignificant because the germ cell is not radiosensitive.

Question 22

Which of the following tissues contain cells that do not divide?
1)Epithelial tissue
2)Muscle tissue
3)Nervous tissue in an adult

A)1 and 2 only
B)1 and 3 only
C)2 and 3 only
D)1,2,and 3

Question 23

If bone marrow cells have not been destroyed by exposure to ionizing radiation,they can:

A)become insensitive to future exposures from ionizing radiation.
B)overpopulate and become radioresistant.
C)remain in circulating blood indefinitely.
D)repopulate after a period of recovery.

Question 24

Which of the following is a scavenger type of white blood cell that fights bacteria?

A)Granulocytes
B)Lymphocytes
C)Neutrophils
D)Thrombocytes

Question 25

Neutrophils play an important role in:

A)circulating blood through the human body.
B)clotting blood.
C)fighting infection.
D)preventing hemorrhage.