Ch. 7 Biological Effects from Ionizing Radiation

Question 1

LET

Answer 1

Average energy deposited/unit length

Question 2

Free radicals

Answer 2

Possess the ability to attack and damage organic molecules

Question 3

Mitotic delay

Answer 3

The failure of the cell to start dividing on time

Question 4

Point mutations

Answer 4

Genetic mutations at the molecular level

Question 5

RBE

Answer 5

Describes the relative capabilities of radiations with various LET’s to produce a particular biologic reaction

Question 6

Undifferentiated cells

Answer 6

Non-specialized immature cells

Question 7

Well-differentiated cells

Answer 7

Mature cells specialized in function

Question 8

QF

Answer 8

Modifying factor - basically a measure of RBE

Question 9

Hyperbaric oxygen

Answer 9

High pressure oxygen

Question 10

Stem cells

Answer 10

Immature blood cells

Question 11

Hypoxic cells

Answer 11

Cells that lack adequate amounts of oxygen

Question 12

Radiation damage is observed on three levels:

Answer 12

Molecular, cellular, and organic

Question 13

The effect of ionizing radiation that is most harmful to the human body is the…

Answer 13

Direct effect (takes high LET)

Question 14

With respect to the law of Bergonie and Tribondeau, what would best complete this statement? “The greatest radiation effects occur in cells having the…”

Answer 14

Most reproductive activity, longest mitotic phases, and least maturity

Question 15

Which of the following groups of cells are most radiosensitive?

Answer 15

Lymphocytes

Question 16

Which of the following is considered to be a low-LET radiation?

1. X-rays
2. Alpha particles
3. Gamma rays

Answer 16

x-rays and gamma rays

Question 17

Ionizing radiation causes complete chromosome breakage when…

Answer 17

Two direct hits occur in the same rung of the DNA macromolecule

Question 18

What type of cell is least radiosensitive?

Answer 18

Adult nerve cells

Question 19

OH~ +OH~ =

Answer 19

H2O2

Question 20

The dose of a reference radiation quality, stated in grays, necessary to produce the same biological reaction in a given experiment that is produced by a dose of the test radiation simply defines:

Answer 20

RBE

Question 21

While passing through a human cell, an x-ray photon interacts with and inactivates the cell’s master molecule. The consequence to the cell is:

Answer 21

Death