​Co-Dominance

a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual.

​Incomplete Dominance

a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype

​Non-Mendelian Genetics

• Patterns of inheritance in which traits do not follow Mendel’s laws

• Many traits have more complicated modes of inheritance than just simple dominant versus recessive with two alleles

  • Example: Multiple Allele Inheritance

​Multiple Allele Inheritance

Multiple Allele inheritance means there are more than just 2 alleles

We will use Blood Typing

​Blood Types

Humans have A, B, AB, O
Possible Genotypes:
A= AA or AO * can be also represented as I^AI^A or I^Ai = A
B= BB or BO I^BI^B or I^Bi = B
O= OO ii = O
AB= AB I^AI^B = AB

​Rules for Bloodtyping

Both A and B blood types are Co-Dominant in heterozygous individuals


Both A and B blood types are Dominant to O blood type.

​What is "Blood Typing"?

The allele for blood type codes for antigens (markers) on your blood cells

A type= A antigen
B type= B antigen
O type= NO ANTIGEN

​Blood Typing Continued

Anitgens (markers) are how your body recognizes its own cells versus invaders.

A Allele= B antibodies
B Allele= A antibodies
O Allele = A and B antibodies