128 CHAPTER 9 



Curt Stern, in the early 1930's. 



REFERENCES 



Committee on Standardized Genetic Nomenclature for Mice, "A Revision of the 

 Standardized Genetic Nomenclature for Mice," J. Heredity, 54:159-162, 1963. 



Creighton, H. S., and McClintock. B., "A Correlation of Cytological and Genetical 

 Crossing-over in Zea Mays," Proc. Nat. Acad. Sci., U.S., 17:492-497, 1931. 

 Reprinted in Classic Papers in Genetics, Peters, J. A. (Ed.), Englewood Cliffs, 

 N.J.: Prentice-Hall, 1959, pp. 155-160; also in Great Experiments in Biology, 

 Gabriel, M. L., and Fogel, S. (Eds.), Englewood Cliffs, N.J.: Prentice-Hall, 1955, 

 pp. 267-272. 



Morgan, T. H.. "Random Segregation Versus Coupling in Mendelian Inheritance," 

 Science, 34:384, 1911. Reprinted in Great Experiments in Biology, Gabriel, 

 M. L., and Fogel, S. (Eds.), Englewood Cliffs, N.J.: Prentice-Hall, 1955, pp. 

 257-259. 



Stern, C, "Zytologisch-genetische Untersuchungen als Beweise fur die Morgansche 

 Theorie des Faktorenaustauschs," Biol. Zbl., 51:547-587, 1931. 



QUESTIONS FOR DISCUSSION 



9.1. Distinguish between sex-linkage and the linkage of nonalleles. 



9.2. Does the linkage of two genes prove they are located on the same chromosome? 

 Explain. 



9.3. Discuss the advantages and disadvantages of linkage and crossing over with 

 respect to the fitness of individuals carrying certain genotypes. 



9.4. In Drosophila, y and spl are X-linked. A female genotypically + +/y spl pro- 

 duces sons. If 3% carry either y + or + spl, what are the genotypes and rela- 

 tive frequencies of gametes produced by the mother? Is the father's genotype 

 important? Explain. 



