DIHYBRID PRACTICE PROBLEMS

R = running mice B = Black mice r = waltzing mice (run in circles) b = brown mice

1. RrBb x RRbb What are the possible genotypes? What is the phenotypic ratio?

2. rrBb x Rrbb What are the possible genotypes? What is the phenotypic ratio?

3. Cross a heterozygous running, heterozygous black mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?

4. Cross a homozygous running, heterozygous black mouse with a homozygous running, brown mouse. What are the possible genotypes? What is the phenotypic ratio?

5. Cross a waltzing brown mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?

DIHYBRID PRACTICE PROBLEMS

R = running mice B = Black mice r = waltzing mice (run in circles) b = brown mice

1. RrBb x RRbb What are the possible genotypes? What is the phenotypic ratio?

2. rrBb x Rrbb What are the possible genotypes? What is the phenotypic ratio?

3. Cross a heterozygous running, heterozygous black mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?

4. Cross a homozygous running, heterozygous black mouse with a homozygous running, brown mouse. What are the possible genotypes? What is the phenotypic ratio?

5. Cross a waltzing brown mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?

DIHYBRID PRACTICE PROBLEMS

R = running mice B = Black mice r = waltzing mice (run in circles) b = brown mice

1. RrBb x RRbb What are the possible genotypes? What is the phenotypic ratio?

2. rrBb x Rrbb What are the possible genotypes? What is the phenotypic ratio?

3. Cross a heterozygous running, heterozygous black mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?

4. Cross a homozygous running, heterozygous black mouse with a homozygous running, brown mouse. What are the possible genotypes? What is the phenotypic ratio?

5. Cross a waltzing brown mouse with a waltzing brown mouse. What are the possible genotypes? What is the phenotypic ratio?