1. In rumbunnies spock ears (D) are dominant to earless (d); red eyes (A) are dominant to blue eyes (a); and spinner eyes (E) are dominant nonspinner eyes (e). An individual heterozygous for all three alleles is testcrossed.
a. Forecast the phenotypic ratio for this cross. (Note: You can do a Punnet square, but it will be a lot easier to use probability.)
b. Predict the probability that 2 out of 4 progeny from this cross will be earless, with blue spinner eyes.
c. You perform this cross several more times to determine if these three genes are independently assorting and observe the following results. Answer the following questions:
Phenotype |
Observed Number |
Spock, red, spinner |
429 |
Spock, red, nonspinner |
34 |
Spock, blue, spinner |
50 |
Spock, blue, nonspinner |
1 |
Earless, red, spinner |
4 |
Earless, red, nonspinner |
50 |
Earless, blue, spinner |
36 |
Earless, blue, nonspinner |
440 |
i. State your null hypothesis.
ii. Conduct a chi-square analysis to see if your observed data are consistent with your hypothesis.