Complex Patterns Of Inheritance

By Saydee Deal

Incomplete Dominance

In Incomplete Dominance, NEITHER gene completely DOMINATES one another. So say you have a Red flower and a White flower. When these come together to make another flower, the red and white flower make a PINK flower. They basically combine to make the phenotype. Offsprings that are Heterozygous now have a phenotype in between the homozygous alleles.

Another Example of Incomplete Dominance

When your mom has curly hair and your dad has straight hair, when they come together to have an offspring, the child may come out with wavy hair.


In codominance, BOTH alleles show up in the phenotype. Offsprings that are heterozygous both show up. Say you have a white cow and a brown cow. When they come together to make on offspring, the cow may be white with brown spots.

Codominance Example

A black rooster and a white rooster make an offspring. The offspring has a white body with black wings and a black tale.

Multiple Alleles

In multiple alleles, traits are controlled by 3 or more alleles rather than just the original 2.

Example of Multiple Alleles

Polygenic Traits

In Polygenic traits, traits are controlled by more than one gene. Skin color is the best example.