Incomplete & Co-dominance

Incomplete Dominance Genotype is heterozygous (ex: Rr) Phenotype is between two parents Neither gene is completely dominant over the other Ex: Red flower (RR) x White flower (rr) = Pink flowers (Rr)

Co-Dominance In Co-dominance, both alleles contribute to the phenotype of the organism. Genotype is heterozygous (ex: Bb) Ex: Roan Cow - Shows 2 different colors. Brown (BB) x White (bb) = Brown and White (Bb)

Multiple Alleles Many genes have more than 2 alleles and are said to have multiple alleles. Ex: Human Blood type – Controlled by 3 alleles – A,B,O Possible blood types: Type A – (AA, AO) Type B – (BB, BO) Type AB – (AB) Type O – (OO)

Describe sex-linked alleles Sex-linked alleles: controlled by genes located on sex chromosomes Usually carried on X chromosome Since females are XX, they are usually carriers of the trait Since males are XY, they have a higher tendency for inheritance of trait

Pedigrees Pedigrees: graphic representation of a family tree Symbols identify sex, if they are carriers, if they have a certain trait, etc. Used to show how one trait has been passed along in a family

Pedigree Analysis Pedigrees use symbols to illustrate inheritance