1. Incomplete Dominance Neither allele is dominant over the other
Heterozygous offspring have a phenotype that is somewhere between the two.
Red + White = ___________

2. Incomplete Dominance RR x WW yields heterozygous offspring
Homozygous red parent: RR
crossed with
Homozygous white parent: WW
RR x WW
yields heterozygous offspring
RW that are pink

3. Incomplete Dominance

4. X Codominance Both alleles contribute to the phenotype
Heterozygous offspring express both alleles X

5. Codominance: A black chicken crossed with a white chicken results in a speckled chicken
How is this type of inheritance different from incomplete dominance?

6. Multiple Alleles > 2 possible alleles exist in a population
Coat color in rabbits: at least 4 different alleles
C = full color (dominant other alleles)
c (ch) = chinchilla
c (h) = himalayan
c = albino (recessive other alleles)

7. Full Color Rabbit (C)

8. partial defect in pigmentation: c (ch)
Chinchilla Rabbit
partial defect in pigmentation: c (ch)

9. Himalayan Rabbit
Color in only certain parts of body: c (h)

10. Albino Rabbit (c)

11. Polygenic Traits
Traits that are produced by the interaction of more than one different genes
Example: coat color in Labrador retrievers is a result of interaction of 2 different genes.

12. Polygenic Inheritance
2 or more genes work together to create a single phenotype
Ex: Eye color, skin color

13. Polygenic Inheritance
Example: comb shape in chickens is a result of interaction between 2 different genes.

14. Epistasis
When one gene product affects the expression of another gene.
B, b = fur color alleles
bb = brown fur
Fur color only expressed if C gene is also present