exceptions to mendel’s laws. 1) incomplete dominance some alleles are not completely dominant and...

Exceptions to Mendel’s laws

1) Incomplete dominance

Some alleles are not completely dominant and the offspring will have a “blending” of the parents traits.

EX: Red flower x White flower Pink flowers

Incomplete dominance

2) Codominance

2 alleles are equally dominant and both are expressed in the offspring.

EX: Roan horses and cows really have white & red hair (they appear brownish). Both hair colors show up when a white horse is bred to a “red” horse.

Codominance

3) Multiple Allele Traits

A trait that has more than just 2 types of alleles.

EX: human blood types** (also show codominance)

Multiple allele traits

4) Polygenic Traits

A trait that is controlled by more than 1 gene.

EX: human skin color, height, and eye color

5) Sex linked traits (X-linked)

Some traits are found on the sex chromosomes instead of autosomes and are more likely to show up in one gender.

EX: colorblindness & hemophilia

**these traits generally affect males more than females.