11. Which of the following would be the most accurate way to measure the reproductive integrity of cells exposed to ionizing radiation? 

A. Comet assay 

B. Clonogenic assay 

C. Fluorescence in situ hybridization 

D. Micronucleus assay 

E. Tumor regrowth delay assay

12. The D₀ is the dose that results in an average of one lethal event per cell. When there is no repair of sub-lethal damage, exposure of cells with a D₀ dose will result in which of the following survival fraction? 

A. 100% 

B. 63% 

C. 50% 

D. 37% 

E. 10% 

13. In the clonogenic assay for a new cell line, four cell culture dishes were seeded with 10², 10³ , 10⁴ and 10⁵ cells, and irradiated with 0, 2, 4 and 6 Gy of X-ray, respectively. After 10-day incubation, total 50 colonies were counted on each dish. Which one of the following statements about the survival curve from this experiment is true? 

A. The D₀ for this cell line is 2 Gy 

B. The cell surviving fraction after a dose of 2 Gy is 0.05 

C. The α/β ratio for this cell line is small 

D. The survival curve for this cell line is exponential 

E. The n and D_q values for this survival curve are large 

14. A set of data defining the survival of cells irradiated with graded doses of X-rays is well-fitted by the mathematical expression for a single-hit survival curve having the surviving fraction at 4 Gy of 0.37. The best estimate for the α parameter that describes this survival response is: 

A. 0.01 Gy^-1

B. 0.1 Gy^-1

C. 0.25 Gy^-1

D. 0.5 Gy^-1

E. 1.0 Gy^-1 

15. The survival curve for a cell population irradiated with a form of high LET radiation is characterized by a D₁₀ (dose reducing the SF to 10%) of 2 Gy. For a starting population of 10⁹ cells, approximately how many cells will survive when a single dose of 18 Gy is given? 

A. 10⁰

B. 10¹

C. 10²

D. 10³

E. 10⁴