VARIATIONS TO SIMPLE DOMINANCE Its not always as straight forward as it seems…

THE PROBLEM… A red carnation is crossed with a white carnation. The resulting flowers are all pink. What is up with that?

Incomplete Dominance –Neither allele dominates the other –Phenotype is intermediate –Red flower + White flower = pink flower –Tall plant + Short plant = medium plant

THE SYMBOLISM ISSUE Red is not dominant White is not recessive We can no longer use capital and lower case letter as symbolism

THE SYMBOLISM ISSUE We use a base letter – C for “color” And a superscript to indicate which one.

INCOMPLETE DOMINANCE THE MONOHYBRID CROSS

CROSS TWO F1 OFFSPRING CROSS TWO PINK FLOWERS

THE PUNNET SQUARE

CODOMINANCE –CO MEANS SHARED OR DONE TOGETHER –Is similar to Incomplete dominance –BUT Instead of blending, –both traits show up! WADDING ROCKS!!!! I am a squirl Do Humans taste like chicken ?

CODOMINANCE –BOTH TRAITS SHOW UP!!! –Black chicken + White chicken = chicken with both black feathers and white feathers

CODOMINANCE –BOTH TRAITS SHOW UP!!! –BROWN horse and a WHITE horse produce a roan horse – both BROWN hairs and WHITE hairs…