Gene Interaction and P/ienotvpic Expression 



55 



REFERENCES 



Bateson, W., Mendel's Principles of 

 Heredity, Cambridge, England, 

 Cambridge University Press, 

 1909. 



Bibliography on the Genetics of Dro- 

 sophila: Part I by H. J. Muller 

 (Edinburgh, Oliver and Boyd, 

 1939, 132 pp.). Parts II and III 

 by I. H. Herskowitz (Oxford, 

 Alden Press, 1953, 212 pp., and 

 Bloomington, Indiana University 

 Press, 1958, 296 pp., respectively). 



William Bateson (1861-1926). 



(By permission of Genetics, Inc., 



vol. 12, p. 1, 1927.) 



QUESTIONS FOR DISCUSSION 



7.1. Does this Chapter present any new information about genetic recombination? Explain. 



7.2. What is the maximum number of genotypes possible in the progeny if the parents are 

 monohybrids? 



7.3. Two green corn plants when crossed produce offspring of which approximately ^(b are 

 green and Ke are white. How can you explain these results? 



7.4. Does genie interaction occur only when identical monohybrids (or identical dihybrids) 

 are crossed? Explain. 



7.5. Three walnut-combed chickens were crossed to single-combed individuals. In one 

 case the progeny were all walnut-combed. In another case one of the progeny was 

 single-combed. In the third case the progeny were either walnut- or pea-combed. 

 Give the genotypes of all parents and offspring mentioned. 



7.6. Would you expect to find epistasis in man in marriages involving genetic alternatives: 



a. For woolly hair and for baldness? 



b. For brown eyes and for albinism? 



c. For baldness and for brown eyes? 



d. For ABO blood type and for MN blood type? 



7.7. When two plants are crossed it is found that % of the progeny are phenotypically like 

 the parents, while %i of the progeny are different from either parent but resemble each 

 other. Give a genetic explanation for this. 



7.8. Suppose two unrelated albinos married and had eight children, four albino and four 

 nonalbino. How could you explain these results? 



