WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.

WLHS/Biology/Oppelt

Name_______________________________ Date_______________

Genetics Practice Problems

Incomplete Dominance and Codominance

1. Set up genotypic keys for the phenotypes listed in each set. Remember that the "medium" trait must always be

heterozygous.

a) Birds can be blue, white, or white with blue-tipped feathers. ____________________

b) Flowers can be white, pink, or red. ___________________

c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked. ______________

d) A Sneech can be tall, medium, or short. _________________________

e) A Bleexo can be spotted, black, or white. ________________________

2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are

incomplete.

Codominant _____________ Incompletely Dominant ________________

3. In a certain strain of Sweet William plants, flowers color is controlled by 1 gene with 2 alleles.

RR produces red flowers, Rr produces pink flowers, and rr produces white flowers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross

between a red plant and a white plant.

c. What are the expected genotypic and phenotypic ratios of red, pink, and white flowers in a cross

involving two pink flowers. Show your work.

4. A cross between chicks with frizzled feathers and plain chicken produced chicks with “slightly frizzled”

feathers.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a slightly

frizzled rooster with a plain hen.

b. Now cross a slightly frizzled rooster with a frizzled hen. Show your work and ratios.

For Questions 4-6, use the following Smileys.

4. In Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured

phenotypes

___________ ___________ ______________

5. Show the cross between a star-eyed and a circle eyed.

What are the phenotypes of the offspring? ____________

What are the genotypes? __________

6. Show the cross between a circle-star eyed, and a circle eyed.

How many of the offspring are circle-eyed? ____________

How many of the offspring are circle-star eyed? ____________

7. All palomino horses are heterozygous. Crosses between palominos yield brown, palomino, and white foals in

an appropriate 1:2:1 ratio. Using the symbols BB = brown, Bb = palomino, bb = white.

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between two

palomino horses.

8. In shorthorn cattle, the red coat color is codominant over the white coat color. The heterozygous condition is

roan (both red and white hairs are produced).

a. Is this problem an incomplete dominance or codominance problem?

b. Show the cross, Punnet square, genotypic ratio, and phenotypic ratio for a cross between a red bull

and a white cow.

b. Cross two roan colored cattle. Show your work and ratios.