Dihybrid Cross Problems:
Use Punnett Squares to solve these problems. You MUST show your work!
1. Some dogs bark when trailing, others are silent. The barking trait is due to a dominant
gene. Standing ears are dominant to drooping ears. Show the cross between a
heterozygous standing-eared braker, and a homozygous droopy eared silent trailer.
a. What is the phenotypic ratio?
b. What is the genotypic ratio?
2. In guinea pigs, rough coat is dominant to smooth coat; and short hair is dominant over
long hair. Cross a guinea pig homozygous for a rough and short coat with a guinea pig with
a smooth long hair. After doing the cross, write the expected phenotypic and genotypic
ratios of the offspring.
a.Summarize the Phenotypes:
b. Summarize the Genotypes:
