Unit 5 – Other forms of inheritance Not all traits are simply dominant or recessive, with only 2 possible alleles. Incomplete Dominance = BLENDING in heterozygotes.
Not all traits are simply dominant or recessive, with only 2 possible alleles.
Red = RRWhite = WWPink = RW
Phenotype ratio: 100% Pink
Genotype ratio: 100% heterozygous
Co-dominance = TOGETHER or SPOTTED – both traits are FULLY and SEPARATELY expressed
BB = Black
WW = White
BW = Black AND White hairs together
Cross a cow and a bull that have black and white hairs.
Phenotype: 25% Black, 25% white, 50% black and white
Genotype: 25% homozygous black, 25% homozygous white,
Cross a heterozygous normal vision female with a normal vision male. (First cross sex chromosomes, then put on alleles and cross them).
50% Normal vision females25% Normal vision males
25% Color Blind males
Genotype: 25% XBXb (Carrier)
Human Blood Types: Use both co-dominance and regular dominant/recessive.
Cross a person who is homozygous for type A blood with a person who has type AB blood.
Phenotype Ratio: 50% Type A, 50% Type AB
Genotype Ratio: 50% AA, 50% AB