Genes: Nature and Mode of Action - 537 



12. Briefly discuss and exemplify each of the fol- 

 lowing topics: 



a. an experimental technique that demon- 

 strates whether a given part of the em- 

 bryo is determined or not determined 



b. an experiment that shows that the pres- 

 ence of one cell (dead or alive) can in- 

 fluence the development of all the other 

 cells in the embryo 



13. 



c. the role of the dorsal lip of the blasto- 

 pore as an embryonic organizer 



d. the time at which determination occurs 

 in the different parts of a frog embryo 



e. the nature of the organizing influence 

 of the dorsal lip 



Discuss briefly the possible ways in which the 

 genes may affect the metabolism and hence 

 the development of a given cell. 



FURTHER READINGS 



1. Experimental Embryology, by T. H. Morgan; 

 New York, 1927. 



An Introduction to Experimental Embryology, 

 by G. R. DeBeer; New York, 1934. 

 Principles of Development, by Paul Weiss; 

 New York, 1939. 



Section on "Bacterial Transformation," by 

 O. T. Avery, C. M. MacLeod, and M. McCarty, 



2. 



3. 



in Great Experiments in Biology, ed. by M. 

 Gabriel and S. Fogel; Englewood Cliffs, N. J., 

 1955. 



Articles in Scientific American by G. W. 

 Beadle (September 1948); R. D. Hotchkiss 

 and E. Weiss (November 1956); F. H. C. Crick 

 (October 1954 and October 1962); and M. W. 

 Nirenberg- (March 1963). 



