Question

The F2 generations of dihybrid crosses of Labrador retrievers are expected to produce the recessive epistatic ratio of 9 black: 3 chocolate: 4 yellow dogs. A random sample of 80 dogs was taken from F2 crosses. What is the expected number of yellow labs in the sample and what number of degrees of freedom is needed for a chi-square test of recessive epistasis

Answer 1

Answer:

The answer is "2 and 15"

Explanation:

sample of the chocolate labs expected number =chocolate labs fraction $\times$ sample size

$= (\frac{3}{16}) \times 80\\\\ = 15$  

The dof for recessive epistasis is = n-1, where

n =phenotypes

dof $= 3-1 = 2$