RT 230 - Radiation Biology Exam 2006

MULTIPLE CHOICE.

On the line to the left, place the letter of the choice that best answers the question. Three Points Each. NOTE: "e" answers are never the correct answer.

1. Radiation sensitivity is

_______   a. Roughly equal between embryo and infant
                b. Highest during adolescence
                c. Lowest during adulthood
                d. Lowest in adulthood and old age
                e. Do we really care if radiation is easily upset-?



2. Telomere activity is an important aspect in

_______    a. Aging                     b. Radiation absorption                c. Gene expression
                d. Target theory                        e. Processes that no one cares about
 


3. In the term LD50/60, the 60 part represents

_______    a. Percent of the group                     b. Percent of cells                    c. Days
                d. Hours                            e. How many times I'm beating myself up for forgetting this
 


4. In the oxygen enhancement ratio, what does the oxygen enhance?

_______    a. Cell recovery                     b. Gene expression                    c. Image contrast
                d. Radiation sensitivity                        e. It lets the natural beauty shine through
 


5. A person can become radioactive if

_______    a. They absorb enough radiation                               b. They take in radioactive materials
                c. They absorb the "right" kind of radiation                d. All of the above
                                                                e. Um, wait a minute...
 


6. Radiation damage to proteins has limited impact on cells because

_______    a. Proteins are very difficult to damage                                b. They can only be hurt directly
                c. Cells normally deal with damaged proteins anyway            d. Cells don't depend much on proteins
                                                e. Even undamaged proteins are really annoying


7. A single point mutation that substitutes one nucleotide for another will change how much of a codon?

_______   a. All of it                     b. One half                     c. One fifth                    d. One third                     e. A smidge

 


8. The problem with known radioprotectors is that they are

_______    a. Much too expensive                     b. Highly toxic                    c. Not selective enough
                d. Sensitive to water content                        e. Not available in enough stylish colors

 


9. Which comes closest to expressing the idea of hormesis?

_______    a. A little radiation is good for a person                                b. Any radiation at all is bad
                c. Diagnostic exposure is worth the risk                                d. You can appear healthy but still be dying
                                            e. Weird words on exams are never a good sign


10. X ray exposure on the atomic level can cause the loss of

_______    a. Protons                 b. Neutrons                 c. Electrons                d. All of the above             e. Bladder control

 


11. When a cancer metastasizes, the cells

_______    a. Divide much faster                 b. Become resistant to treatment                c. Begin to change the cells around them
                d. Begin to migrate                                                e. Pick up a major ‘tude
 



12. Radiation-induced blindness is most likely to result from

_______    a. Retinal detachment                 b. Cataracts                c. Glaucoma                 d. Macular degeneration
                                                e. Looking at too many patients in those gowns

 


Short Answer.

Pick SIX questions to answer in the spaces provided.
NOTE: if you answer MORE than six, only the first six will be corrected.
Four Points each. Partial credit is possible.
 

1. What are two pathways by which radiolysis of water can have indirect damaging effects in a cell?
 

 

 

  
2. In target theory, what is the target?
 

 

 
3. What are four different types of cellular organelles found in the cytoplasm?


 		  


 		  
4. In general, what's the relationship between the linear energy transfer (LET) of a radiation type and its penetration ability?
 

 

 
5. What two aspects of the prodromal period is used to guess how severe a radiation dose a person has received?
 

 

 

  
6. What two parts of a human cell both have DNA in them?
 

 

 

  
7. What's an SED50? Don't just say what that stands for - what is it?
 

 

 
8. What is apoptosis?
 

 

 
9. Pick one type of risk assessment - name it and describe how it's assessed.
 

 

 
10. Under the Law of Bergonie and Thibodeau, what are two features found in cells that increases their vulnerability to radiation?
 

 

 

  
11. Why are most point mutations essentially neutral in effect?
 

 

 
12. Pick one cellular component of blood. Name it, and explain how radiation exposure to bone marrow affects their levels in the blood over time.
 

 

 
13. What are two different factors that can produce a threshold effect for radiation damage?
 

 

 

  



Long Answer.

Select and answer completely any four of the following questions.
Note: if you answer more than four, only the first four will be corrected.
Ten Points Each. Partial credit is possible.
 

1. For gonad exposure in the two genders, briefly fill in the information.
  Time Period over which most effects from radiation damage will show up Why this particular time period

MALE

  

 

 

  

FEMALE

  

 

 

  
2. For three general types of tissue, name the type, give the general radiosensitivity (low / medium / high, possibly ranges), and explain why it has that sensitivity.
TISSUE TYPE RADIOSENSITIVITY Explanation
 

 

 

    
 

 

 

    
 

 

 

    
3. For the three acute radiation syndromes, give the name of the syndrome, then briefly explain the reason why it has its effects (types of tissue affected & result of effects).
 

 

 

  
 

 

 

  
 

 

 

  
4. Briefly explain, step-by-step, the most common way radiation can bring about the death of a tumor. Talk about what's going on in the cells.
 

 

 

 

 

 

 

 
5. What are five different sorts of cellular effects of radiation damage?
 

 

  
 

 

 

  
 

 

 

  
6. What are five different types of cancer that have been directly linked to radiation damage?
 

 

  
 

 

 

  
 

 

 

  
7. There are four basic factors that determine, in general, the amount of damage that radiation will do. What are they?
 

 

 

  
 

 

 

  


Link to Answer Key


BONUS QUESTIONS.

Answer as many as you are able. Wrong answers will not result in points being lost from the main exam. You can get partial credit on these answers.

How does the radiation in a microwave oven cause food to heat up? Three Points.



Why, probably, does a heavy dose of radiation cause a mobilization of white blood cells? Three Points.



A diagnostic x-ray represents a unit of 1 on what scale? Three Points.



The "rules" of cell-survival kinetics are worked out in cell cultures. Why might that be unreliable? Three Points.



Briefly explain the idea behind Poisson distribution. Three Points.



What is forecast to happen to 25% of the people on any mission to Mars? Three Points.



In general, what common factor has the biggest effect on shortening life span? Three Points.



Briefly explain the effect that cross-linking may have on stereospecificity. Three Points.


  
     

 

 

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