RADT 1200 - MOLECULARS &
CELLULAR RADIATION BIOLOGY
EXAM QUESTIONS AND ANSWERS
A multistage process that first involves the production of reactive free radicals that
are created by the interaction of radiation with water molecules - Answer- Indirect
action
Concept that the cell dies if the master, or key, molecule becomes inactive as a
consequence of exposure to ionizing radiation - Answer- Target theory
Solitary atoms or most often a combination of atoms that behave as single entities
and are very chemically reactive as a result of the presence of unpaired valence
electrons - Answer- Free radicals
Used to calculate the equivalent dose to determine the ability of a dose of any kind
of ionizing radiation to cause biologic damage - Answer- Radiation weighting
factor (Wr)
Loss or change of a nitrogenous base in the DNA chain - Answer- mutation
Results when irradiation occurs early in interphase, before DNA synthesis takes
place - Answer- Chromosome aberrations
Describes the relative capabilities of radiation with differing LETs to produce a
particular biologic reaction - Answer- RBE - relative biologic effectiveness
Chemical unions created between atoms by the single sharing of one or more pairs
of electrons - Answer- Covalent cross-links
Programmed cell death - Answer- apoptosis
the radiosensitivity of cells is directly proportional to their reproductive activity and
inversely proportional to their degree of differentiation - Answer- Law of Bergonie
and Tribondeau
The ratio of the radiation dose required to cause a particular biologic response of
cells or organisms in an oxygen-deprived environment to the radiation dose required
to cause an identical response under normal oxygenated conditions - Answer-
OER - Oxygen Enhancement Ratio
, Classic method of displaying the sensitivity of a particular type of cell to radiation -
Answer- cell survival curve
Results when irradiation of individual chromatids occurs later in interphase, after
DNA synthesis has taken place - Answer- Chromatid aberrations
Biologic damage that occurs as a result of atoms on essential molecules (DNA)
produced by straight interaction with the incident radiation - Answer- Direct action
The average energy deposited per unit length of track - Answer- LET - Linear
energy transfer
The breaking of one or both of the sugar-phosphate chains of a DNA molecule that
can be caused by exposure of the molecule to ionizing radiation - Answer-
Chromosome breakage
Branch of biology concerned with the effects of ionizing radiation on living systems -
Answer- radiation biology
Injury on the molecular level resulting from exposure to ionizing radiation - Answer-
molecular damage
Female & male reproductive cells - Answer- germ cells
A hydrogen radical and a hydroxyl radical - Answer- H* and OH*
Can result when ionizing radiation interacts with a DNA macromolecule and the
energy transferred in the process ruptures one of its chemical bonds and severs one
of the sugar-phosphate chain side rails, or strands, of the ladderlike molecular
structure - Answer- Point mutation
A hydroperoxyl radical - Answer- HO2*
an organic neutral free radical - Answer- R*
OH* + OH* = h202, a substance that is very poisonous to the cell - Answer-
hydrogen peroxide
Exposing a cell to as little as 0.01gyt of ionizing radiation just before it begins
dividing can result in the failure of the cell to start dividing on time - Answer-
mitotic delay
Radiation damage is observed on what 3 levels? - Answer- molecular, cellular,
organic systems
CELLULAR RADIATION BIOLOGY
EXAM QUESTIONS AND ANSWERS
A multistage process that first involves the production of reactive free radicals that
are created by the interaction of radiation with water molecules - Answer- Indirect
action
Concept that the cell dies if the master, or key, molecule becomes inactive as a
consequence of exposure to ionizing radiation - Answer- Target theory
Solitary atoms or most often a combination of atoms that behave as single entities
and are very chemically reactive as a result of the presence of unpaired valence
electrons - Answer- Free radicals
Used to calculate the equivalent dose to determine the ability of a dose of any kind
of ionizing radiation to cause biologic damage - Answer- Radiation weighting
factor (Wr)
Loss or change of a nitrogenous base in the DNA chain - Answer- mutation
Results when irradiation occurs early in interphase, before DNA synthesis takes
place - Answer- Chromosome aberrations
Describes the relative capabilities of radiation with differing LETs to produce a
particular biologic reaction - Answer- RBE - relative biologic effectiveness
Chemical unions created between atoms by the single sharing of one or more pairs
of electrons - Answer- Covalent cross-links
Programmed cell death - Answer- apoptosis
the radiosensitivity of cells is directly proportional to their reproductive activity and
inversely proportional to their degree of differentiation - Answer- Law of Bergonie
and Tribondeau
The ratio of the radiation dose required to cause a particular biologic response of
cells or organisms in an oxygen-deprived environment to the radiation dose required
to cause an identical response under normal oxygenated conditions - Answer-
OER - Oxygen Enhancement Ratio
, Classic method of displaying the sensitivity of a particular type of cell to radiation -
Answer- cell survival curve
Results when irradiation of individual chromatids occurs later in interphase, after
DNA synthesis has taken place - Answer- Chromatid aberrations
Biologic damage that occurs as a result of atoms on essential molecules (DNA)
produced by straight interaction with the incident radiation - Answer- Direct action
The average energy deposited per unit length of track - Answer- LET - Linear
energy transfer
The breaking of one or both of the sugar-phosphate chains of a DNA molecule that
can be caused by exposure of the molecule to ionizing radiation - Answer-
Chromosome breakage
Branch of biology concerned with the effects of ionizing radiation on living systems -
Answer- radiation biology
Injury on the molecular level resulting from exposure to ionizing radiation - Answer-
molecular damage
Female & male reproductive cells - Answer- germ cells
A hydrogen radical and a hydroxyl radical - Answer- H* and OH*
Can result when ionizing radiation interacts with a DNA macromolecule and the
energy transferred in the process ruptures one of its chemical bonds and severs one
of the sugar-phosphate chain side rails, or strands, of the ladderlike molecular
structure - Answer- Point mutation
A hydroperoxyl radical - Answer- HO2*
an organic neutral free radical - Answer- R*
OH* + OH* = h202, a substance that is very poisonous to the cell - Answer-
hydrogen peroxide
Exposing a cell to as little as 0.01gyt of ionizing radiation just before it begins
dividing can result in the failure of the cell to start dividing on time - Answer-
mitotic delay
Radiation damage is observed on what 3 levels? - Answer- molecular, cellular,
organic systems
