Radiation Biology Exam 1 Prep Questions and Answers With Verified Solutions
2025
Dividing the radiation doses into split fractions has less effect on cell survival for neutrons (high LET)
compared to photon radiation
True or False - ✔✔True
What is the recommended time required between radiation doses in order to allow for reassortment of
the cell population to enter a new radiosensitive cell phase?
4 hours
24 hours
6 hours
2 hours - ✔✔6 hours
Which stage of mitosis is most variable amongst mammalian cells?
G1
G2
S
Z - ✔✔G1
Which cell cycle stage is OER highest in?
G1
S
G2
Z - ✔✔S
What is the prominent HDR source used today?
Iridium-192
Cesium-137
, Iodine-125
Iodine-131 - ✔✔Iridium-192
A decrease in dose rate has decreased cell survival
True or False - ✔✔False
An increase in dose rate for Iridium-192 HDR applications improves local recurrence rates
True or False - ✔✔True
Fractionated doses allow for better repair for multiple-track damage
True or False - ✔✔True
Which phase of the cell cycle is most resistant?
G1
S
G2
M - ✔✔S
Which phase of the cell cycle is associated with the molecular checkpoint gene? - ✔✔G2
Which of the following categories of mammalian cells is the most radioresistant?
Differentiating Intermitotic Cells
Vegetative Intermitotic Cells
Reverting Postmitotic Cells
Fixed Postmitotic Cells - ✔✔Fixed Postmitotic Cells
What was the distance for oxygen diffusion discovered by Thomlinson and Gray in their research?
10 micrometers
2025
Dividing the radiation doses into split fractions has less effect on cell survival for neutrons (high LET)
compared to photon radiation
True or False - ✔✔True
What is the recommended time required between radiation doses in order to allow for reassortment of
the cell population to enter a new radiosensitive cell phase?
4 hours
24 hours
6 hours
2 hours - ✔✔6 hours
Which stage of mitosis is most variable amongst mammalian cells?
G1
G2
S
Z - ✔✔G1
Which cell cycle stage is OER highest in?
G1
S
G2
Z - ✔✔S
What is the prominent HDR source used today?
Iridium-192
Cesium-137
, Iodine-125
Iodine-131 - ✔✔Iridium-192
A decrease in dose rate has decreased cell survival
True or False - ✔✔False
An increase in dose rate for Iridium-192 HDR applications improves local recurrence rates
True or False - ✔✔True
Fractionated doses allow for better repair for multiple-track damage
True or False - ✔✔True
Which phase of the cell cycle is most resistant?
G1
S
G2
M - ✔✔S
Which phase of the cell cycle is associated with the molecular checkpoint gene? - ✔✔G2
Which of the following categories of mammalian cells is the most radioresistant?
Differentiating Intermitotic Cells
Vegetative Intermitotic Cells
Reverting Postmitotic Cells
Fixed Postmitotic Cells - ✔✔Fixed Postmitotic Cells
What was the distance for oxygen diffusion discovered by Thomlinson and Gray in their research?
10 micrometers
