Chapter 4, Problem 2QSDC

Summary Introduction

To analyze:

Hen that is true-breeding for pea comb and un-feathered shanks but is heterozygous for hen feathering was crossed with pure breeding rooster with a rose comb, feathered shanks, and cock-feathering. Considering that the genes assort independently, Question asked to describe the expected outcome of the $\text{F1}$ generation.

Introduction:

There are three traits given in the question, mode of inheritance of the first trait i.e. shape of comb is autosomal, the mode of inheritance of second trait i.e. feathered or un-feathered shank is also autosomal, and mode of inheritance of third trait cock feathering or hen feathering is sex limited. The genotype of rose shaped comb is (RRpp) and genotype of pea shaped comb is (rrPP), genotype of feathered shank is (AABB) and genotype of un-feathered shank is (aabb), and lastly, since the type of feathering (cock or hen) is a sex-limited trait, the female will always show hen feathering (HHff, Hhff or hhff) but in case of male, they will show hen feathering if genotype is (HHff or Hhff) and show cock feathering when both the alleles are in recessive form i.e. (hhff).