Mutational Loads and Their Consequences 251 



28.6. What is the relation between phenotypic detriment, genetic death, and genetic 

 persistence? 



28.7. Discuss the relative importance, to the individual and to the population, of point 

 mutants and gross structural changes in chromosomes. 



28.8. What is the difference, in terms of mutation, between a maximum permissible dose 

 and a doubling dose of ionizing radiation? Is any dose of any radiation safe from a 

 mutational standpoint? Explain. 



28.9. Compare the genetic composition of the mutational load caused by fallout, medical 

 uses of radiation, and atomic reactor accidents. 



28.10. Do you believe it is essential that the general public become acquainted with the 

 genetic etTects of radiation? Why? 



28. 11. What are some of the beneficial uses of radiation? Are any of these based upon the 

 genetic effects of the radiation? If so, give one or more examples. 



28.12. One of the components of fallout is radioactive 1-131, which has a half-life of about 

 a week. Discuss the genetic effects expected in the somatic and germ lines of persons 

 exposed to fallout. 



