Special Cases Nina 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 ABBo Ao A B

Codominance  Chickens  Mother hen is white(Wb) and Father is black (BB)  Both white and black are dominant WB Bb WB Bb Wb 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