Name _____________________________
Incomplete Dominance & Co-Dominance
Incomplete Dominance
O Shows a ________________________________________________________________________
O __________________________________________________
O Creates a “____________” of the two traits
Like ________________________________________
Incomplete Dominance Example
O In Four o’clock flowers the alleles for flower color are both equal therefore neither dominates over
the other. Instead, they blend to create pink flowers if both genes are present. Show a cross between
a red four o’clock flower (RR) and a white flower (WW).
Let’s try one:
O In humans straight hair (SS) and curly hair (CC) are traits that have incomplete dominance, that result
in hybrids who have wavy hair (SC). Cross a curly hair female with a wavy haired male.
O In andalusian chickens, gray is a blend of pure black with pure white. Cross a gray rooster with a gray
hen. Give the genotypes and phenotypes of their offspring.
Co-Dominance
O _______________________________________________________________________________
Like co-authors (both names appear on the cover)
Like co-captains (both people are captains)
Problems are done the same way as incomplete dominance problems
Only difference would be how you would see it in person
Co-Dominance Example
O In cattle, neither red (RR) nor white (WW) hair dominates. Instead, both show up if present to make
a “color” called roan (RW). Show the cross between a roan bull and a roan cow.