Your crossed a red flower to white flower diploid species an

Your crossed a red flower to white flower (diploid species) and got all red F1. You allow the F1 s to self-pollinate. Next year, you plant the seeds and observe the F2 results: 18 red, 12 white. Considering the observed numbers, propose two alternative models of genetic determination of coat color. Model 1: Single gene Model 2: Two genes Describe the two models that may account for the observed colors in F2. For model 1, explain why the F1 looks like red PO. For model 2, name the type of two-gene interaction. Using Chi square goodness of fit test, estimate which model is a better fit to the data. Show your work.

Solution

Answer 8:

Model 1: Law of Dominance

Model 2: Law of Independant Assortment

Answer 8.1: In single gene model of rcombination or determination of coat color, a cross between red and white flower yielded all red flower which means that the red coat colour is dominant over the white coat color of the flower. This can be called as the Law of Dominance. In second cross, where F1 is self pollinated, so, in F2, 18 are red and 12 are white, which means that F1 was heterozygous. When F1 was self pollinated, the independant genes segreggated to produce 2 different colors in F2. Hence, this can be called as Law of Independant Assortment.