In my lab experimentation, all of the parent generation, or flies I started with, were wild-type or mutant phenotypically, but their genotypes were unknown. However, after I mated these flies and they produced offspring, the parental genotypes could be hypothesized based on phenotypic observations and ratios of the F1 and F2 generations. I then could check my observations by testing it using the Chi squared (X2) test.
A. Miniature Wings – (Sex-Linked Recessive)
To determine the inheritance of miniature wings I first crossed a female wild-type with a mutant male. The F1 generation results were 609(WT) females; 596(wild-type) males. 1:0 ratio of wild-type to mutants. The F2 generation results were as followed: females- 618(wild-type) ; Males – 288(wild-type) and 313 (mutant). 3:1 ratio of wild-type to mutant. The reciprocal cross F1 generation produced 585(wild-type) females; 607(mutant) males. This suggests a 1:1 ratio and emphasis a sex-linked trait. The F2 generation confirms this hypothesis with a 1:1:1:1 ratio. The F2 generation results were as followed: Females- 291(Mutant) and 296(wild-type) ; Males- 321(mutant), 310(wild-type). Chi squared test results was 0.0296. I conclude miniature wings was x-linked recessive trait.
B. Eyeless – (Autosomal Recessive)
I first crossed a female mutant with a male wild-type. The F1 generation were all wild-type in a 1:0 ratio. The F2 generation produced a 3:1 ratio of wild-type to mutant with sex not being a factor. The reciprocal cross produced all wild-types in a 1:1 ratio to male wild-type to female wild-type. The F2 generation, again, had a 1:1 ratio of male to female, but a 3:1 segregation of expression of the trait. The pattern between the crosses suggests the trait is autosomal recessive with no difference between the sexes. Chi square was 0.07862.
C. Bar Eyes – (Sex-linked Dominant)
Initially crossing a wild-type female to a mutant male with bar eyes, the F1 generation produced half...