In: Biology
In the fruit fly, Drosophila melanogaster, a wingless female fly is mated to a male that is white-bodied and legless. Assume that all alleles causing these phenotypes are recessive. Phenotypically wild-type F1 female progeny were mated to fully homozygous (mutant) males, and the following progeny were observed:
Phenotypes Number Observed
wingless 324
wild-type 34
white, wingless 135
white 8
white, legless 319
hairless, white, legless 32
hairless 140
hairless, legless 9
(a) With respect to the three genes mentioned in the problem, what are the genotypes of the homozygous parents used in making the phenotypically wild-type F1 heterozygote?
(b) Which gene is in the middle?
(c) What are the map distances for the three genes? A correct formula with the values "plugged in" for each distance will be sufficient.
(d) What is the coefficient of coincidence? A correct formula with the values "plugged in" will be sufficient.
(e) What is the value for interference? Is there positive, negative, total, or no interference?