RRPP
walnut                                 
RRPp walnut         
RrPP walnut       RrPp Walnut

RRpp
rose                                     
Rrpp rose

rrPP
pea                                         rrPp
pea                               

rrpp single

1. Concerning comb shape in chickens, which of the following is
true?

a. The R and P are codominant and produces a walnut comb

b. P is recessive to p and produces a single comb

c. R is recessive to r and produces a rose comb

d. The R gene is dominant to the P gene

2. Which is the most complete and accurate definition of
epistasis?

a. An inheritance pattern where two genes affect a single
trait

b. An inheritance pattern where the observed genotypic ratios
differ from expected ratios

c. An inheritance pattern in which the alleles of one gene mask
the phenotypic effects of different gene

d. An inheritance pattern where a 9:3:3:1 ration is found in the
F₂ generation