SPECIAL VARIATIONS ON THE MONOHYBRID GENETICS PROBLEMS
 Variation # 1 – Incomplete Dominance
o What is Incomplete Dominance?
 This means that one trait does not completely dominate over the other.
 _______________________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
 Examples of Incomplete Dominance
o Example: Hair texture in humans
 You can have a gene for curly hair and one for straight hair.
 ____ = _______________________ ; ____ = ________________________________
 Someone could be:
o _________ = _______________________ hair
o _________ = _______________________ hair
o _________ = what’s that?
 a blend of ___________ and __________________ =
________________ hair
 Sample Problems for Incomplete Dominance
o A species of flower is incompletely dominant for color. You have a pure white
flower and cross it with a pure red flower. Predict the next generation’s phenotypes
and genotypes.
o Take 2 of the offspring from the flower cross done in the previous problem. Cross
those flowers together. Predict the next generation’s phenotypes and genotypes.
SPECIAL VARIATIONS ON THE MONOHYBRID GENETICS PROBLEMS
 Variation # 2 – Codominance
o What is Codominance?
 This means that you have ___________________________ alleles and
___________________________________ alleles.
 If you are heterozygous for the trait, you will show ________________ of the
effects of the two alleles.
 Instead of blending the traits, you have a
_____________________________________________________________________!
 Examples of Codominance
o Example: Hair color in cattle
 You have two alleles for hair color.
 ____ = _____________ hair; ______ = _________________ hair
 A cow could be:
 __________ = ________________ color
 __________ = ________________ color
 __________ = what’s that?
o Having _______________________________________________________.
This creates a spotty pattern of red and white color on the body
– This is called a _______________________ color
 Sample Problems for Codominance
o You mate a red cow with a roan colored cow. Predict the genotypes and
phenotypes of the next generation.
o You have a flower that is codominant for color. You cross a pure yellow flower with
a pure blue flower. Predict the genotypes and phenotypes of the next generation.