Gene Action and Polypeptides 



421 



Harriet Ephrussi-Taylor (see p. 

 296), Boris Ephrussi, and Leo 

 Szilard (see p. 391 ) at Cold Spring 

 Harbor, N.Y. in 1951. (Courtesy 

 of the Long Island Biological Asso- 

 ciation.) 



QUESTIONS FOR DISCUSSION 



32.1. List five diseases in man caused by inborn errors of metabolism. 



32.2. In what respect can an inborn error of metabolism be cured? 



32.3. Do all mutations produce inborn errors of metabolism? Explain. 



32.4. What evidence can you present that genes control different steps of a biosyn- 

 thetic sequence of reactions? 



32.5. Is a study of mutation completely or partially dependent upon the concept of 

 a functional genetic unit? Explain. 



32.6. Do you suppose that proof of the one gene-one primary effect hypothesis would 

 reveal anything about the chemical properties of a gene? Explain. 



32.7. From which of these areas of investigation would you expect to obtain the most 

 information regarding the gene — morphology, physiology, biochemistry? Why? 



32.8. Do you think that the concept of a functional genetic unit has any consequences 

 for the practice of medicine? Explain. 



32.9. In what way is the study of a functional genetic unit related to or dependent 

 upon mutation and the genetic recombinational unit? 



32.10. Is it a significant fact that a glutamic acid in hemoglobin A is replaced by an- 

 other amino acid (valine, lysine, or glycine) in hemoglobins S. C. G. and E? 

 Explain. 



32.11. What are the disadvantages of using human beings as material for investigation 

 of the gene? 



32.12. Using Neurospora, design an experiment to detect crossing over within a gene. 



32.13. Is the one gene-one primary function hypothesis equivalent to the one polypep- 

 tide-one gene hypothesis? Why? 



32.14. What evidence can you give for rejecting the hypothesis that a functional ge- 

 netic unit is equivalent to a single genetic recombinational unit? 



32.15. Would you expect a chemical substance specified in a primary way by a gene 

 to be composed of linearly-arranged parts? Why? 



32.16. Can you apply the term cistron to the one or more recombinational units that 

 determine whether glutamic acid or lysine is located at a particular place in 

 hemoglobin? Why? 



