Special CasesNina and Kristi

Codominance

non identical alleles that express two different phenotypes both present themselves

Blood type

both A and B blood types are dominant

if you inherit both then your blood type is AB

AA Ao

AB Bo

A o

A

B

Codominance

Chickens

Mother hen is white(Wb) and Father is black (BB)

Both white and black are dominant

WB Bb

WB Bb

W b

B

B

Incomplete Dominance

When one Allele is not completely dominant over another

Epistasis

When one gene modifies or masks another

C =pigment c = no pigment B= black b = brown

Sex Linked Genes

Genes that are directly linked to the chromosomes that determine sex

Females inherit both x chromosomes

Males inherit the x and y chromosomes

The x chromosome codes for around 1500 genes

The y chromosome codes for around 80 genes