What Can Fruit Flies Reveal about Inheritance?
Chi-Square test for Case 1
Observed No. (o)
Expected No. (e)
(o-e) 2 (o-e) 2 e Red eyes
2 (to the nearest ten-thousandth)
1. Why is it important to remove the adults in the parental generation? To remove any obstructions in the final results.
2. What generation will their offspring be? The offspring would be F1.
3. Based on the data obtained, is the cross in Case 1 monohybrid or dihybrid? Explain. This case would be a monohybrid because there is only one set of colored eyes being crossed.
4. is the cross in Case 1 sex–linked or autosomal? Explain. The cross in Case 1 is autosomal. There is no way to determine if it is sex-linked.
5. Based on the data obtained, is the most likely mode of inheritance in Case 2 autosomal or sex–linked? Explain. Case 2 would sex-linked. Male fruit flies only ended up with white eyes and red eyes compared to the females who only had red eyes.
6. from the data presented, what is the genotype of the parental (before the F1 generation; not shown here) generation? X+X+ and X+Y
7. Determine the degrees of freedom. This is the number of categories (red eyes or sepia eyes) minus one. For the data in Case 1, what is the number of degrees of freedom? There would be two categories minus one. There would be 1 freedom.
8. Find the probability (p) value for 1