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CHAPTER 10 



10.22. Suppose asci from a given Neurospora cross had spores in the following relative 

 order: 



Spores 



(a) Are x and y linked? 



(h) If not linked, give the crossover distance from its centromere for each, [f 



linked, construct a crossover map for x and y and their centromere. 

 (c) Are any double crossovers involved? Why? 



10.23. The accompanying photograph (courtesy of R. G. Isaacson) shows asci of the 

 fungus Sordaria fimicola. The asci are in various stages of maturity, the most 

 mature containing dark ascospores. What genetic conclusions can you draw 

 knowing that all the asci shown are products of the same parental genotype? 



