Incomplete Dominance and Codominance NonMendelian Genetics RR RR

Incomplete Dominance and Codominance (Non-Mendelian Genetics) R’R’ RR’ RR’

Incomplete Dominance – Both dominant genes are expressed as a “Mixture” of the two traits. Codominance – Both dominant genes are expressed fully in the organism

Black Chicken – BB White Chicken – WW Erminette Chicken - BW Example of Codominance

3) A black chicken and a white chicken are crossed, what is the probability of: White Chickens _____________% Black Chickens _____________% Erminette Chickens ___________%

4) If two erminette chickens are crossed, what is the probability of: White Chickens _____________% Black Chickens _____________% Erminette Chickens ___________%

Red Flowers – RR (R 1 R 1) White Flowers – WW (R 2 R 2) Pink Flowers – RW (R 1 R 2) Optional Annotation Example of Incomplete dominance

6) A pink flowered plant is crossed with a white flowered plant, what is the probability of: Red Flowers _____________% White Flowers _____________% Pink Flowers _____________%

7) Two pink flowered plants are crossed, what is the probability of having: Red Flowers _____________% White Flowers _____________% Pink Flowers _____________%

8) What cross will produce the most pink flowers?

Practice Problems: Black Chicken – BB White Chicken – WW Erminette Chicken - BW Example of Codominance

White Fur Red Fur Example of Codominance Roan Fur

5) Roan Bull crossed with Roan Cow, what is the probability of having: Red Fur _____________% White Fur _____________% Roan Fur _____________%

6) Red Bull crossed with White Cow, what is the probability of having: Red Fur _____________% White Fur _____________% Roan Fur _____________%

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7) If we assume Incomplete Dominance in Tail Length (not the Manx gene) TL – Long Tail Gene (Dominant) TN – No Tail Gene (Dominant) TL TL will produce a long tailed cat TL TN will produce a short tail cat TN TN will produce a cat with no tail

Red Flowers – RR (RR) White Flowers – WW (R’R’) Pink Flowers – RW (RR’) Optional Annotation Example of Incomplete dominance

Andalusian Fowl: Black Feathers – BB White Feathers – B’B’ Bluish Gray – BB’

11) Black Andalusian Chicken crossed with a White Andalusian Chicken, what is the probability of having: Black Feathers_____________% White Feathers_____________% Blue-Gray Feathers_____________%

12) Black Andalusian Chicken crossed with a Blue-Gray Andalusian Chicken, what is the probability of having: Black Feathers_____________% White Feathers_____________% Blue-Gray Feathers_____________%

11) Cross two Blue-Gray Andalusian Chickens, what is the probability of having: Black Feathers_____________% White Feathers_____________% Blue-Gray Feathers_____________%