2 Simple Inheritance Mendel studied simple patterns of inheritance. Found that inheritance was controlled by a dominant allele (B) or recessive allele (b).However, there are many inheritance patterns that are more complex.Most traits aren’t simply dominant or recessive.
3 Incomplete DominanceHeterozygous & Homozygous dominant individuals both have the same phenotype.Example --- Brown eyes= Dominant (B); Blue eyes = Recessive (b)Individual with BB or Bb have what color eyes? Brown
4 Incomplete Dominance Cont. When traits are inherited in an incomplete dominance pattern, the phenotype of the heterozygous is between the pure dominant (BB) and the pure recessive (bb).
6 Codominance Codominant alleles --- Both alleles are expressed equally. Example --- when a certain variety of black chicken is crossed with a white chicken, all offspring are checkered (black & white).Both feather colors are produced by codominant alleles.
7 Multiple AllelesMultiple alleles --- traits controlled by more than 2 alleles.Example of a trait controlled by multiple alleles is blood type.