You identify 3 mutant traits in Drosophila: Purple eyes (pr, recessive to wild-type Red eyes), Stubby bristles (st, recessive to wild-type normal bristles), and Long wings (lw, recessive to wild-type normal wings). You suspect that the genes for these traits might be linked.
You decide that before you actually do your cross, you should test whether the genes are really linked. You do a testcross between with an F1 individual with the following genotype to test one of the possible linkages: +/pr, +/lw. The original parents of this F1 individual were as follows: male parent had red eyes and long wings; female parent had purple eyes and normal wings.
You obtain the following results:
Observed Phenotype
243 red eyes, normal wings
259 purple eyes, long wings
237 red eyes, long wings
261 purple eyes, normal wings
1000 total
Do these results support linkage in this case? Explain your answer using statistics (i.e. perform a chi-square analysis to test the hypothesis that the genes are linked). Use the chi-square table in your lab manual (p. 64) or your textbook (p. 36) to interpret your results. Be sure to show your work and indicate df, p-value, critical value, null hypothesis, etc
You decide that before you actually do your cross, you should test whether the genes are really linked. You do a testcross between with an F1 individual with the following genotype to test one of the possible linkages: +/pr, +/lw. The original parents of this F1 individual were as follows: male parent had red eyes and long wings; female parent had purple eyes and normal wings.
You obtain the following results:
Observed Phenotype
243 red eyes, normal wings
259 purple eyes, long wings
237 red eyes, long wings
261 purple eyes, normal wings
1000 total
Do these results support linkage in this case? Explain your answer using statistics (i.e. perform a chi-square analysis to test the hypothesis that the genes are linked). Use the chi-square table in your lab manual (p. 64) or your textbook (p. 36) to interpret your results. Be sure to show your work and indicate df, p-value, critical value, null hypothesis, etc