1. Incomplete Dominance
&
Codominance

2. Incomplete Dominance red white pink
Defined: When neither allele is dominant and the alleles blend together
No recessive allele
More than 2 different phenotypes can occur
Ex: Many flower colors

3. List the genotypes. 4RW List the phenotypes. 4 Pink
Example: Cross a homozygous red 4 o’clock flower (RR) with a homozygous white flower (WW).
List the genotypes.
4RW
List the phenotypes.
4 Pink
W W R W R W R
pink
pink R W R W
pink
pink

4. List the genotypes. 2RW, 2WW List the phenotypes. 2 Pink, 2White R W R
Example: Cross one heterozygous pink (RW) 4 o’clock flower with a White flower (WW).
List the genotypes.
2RW, 2WW
List the phenotypes.
2 Pink, 2White
R W R W W W W
pink
white R W W W
pink
white

5. Codominance red white roan
Defined: When both alleles are dominant and equally expressed
The colors do NOT blend together, but are equally seen
Ex: Cattle Coat
Red cow x White cow =
Roan Cow
Ex: Human Blood types
Type A x Type B = Type AB
red
white
roan

6. Multiple Alleles Defined: More then 2 alleles control a trait
Ex: Blood Type has 3 alleles
Dominant A allele
Dominant B allele
Recessive O allele
A and B allele are equally codominant

7. Ex: Cross Jason who is homozygous for type A blood with Maria who is homozygous for type B blood.
List the genotypes.
4AB
List the phenotypes.
4 type AB blood
B B A A B A B A B A B

8. Ex: Cross Mike who is heterozygous for type A blood with Lisa who is heterozygous for type B blood.
List the genotypes.
1AB, 1Ao, 1Bo, 1oo
List the phenotypes.
1 type AB blood
1 type A blood
1 type B blood
1 type o blood
Probability of Heterozygous individual?
75%
B o A o A B A o B o o o