Practice: Codominance and Incomplete Dominance

1. Practice setting up 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 Smileys, eye shape can be starred, circular, or a circle with a star. Write the genotypes for the pictured phenotypes

4. Show the cross between a star-eyed and a circle eyed.
What are the phenotypes of the offspring? ____________
What are the genotypes? __________

5. 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? ____________

6. Show the cross between two circle-star eyed.
How many of the offspring are circle-eyed? ____________
How many of the offspring are circle-star eyed? ____________
How many are star eyed? ____________