Incomplete dominance describes the general situation in which the phenotype of a heterozytoe is intermendiate between the two homozygotes on a phenotypic scale. Codominance is the condition where both genes are expressed. Severe, often fatal anemia cause the red blood cells to sickle . Starch gel electrophoresis of proteins is avery powerful tool to study codominance, evolution, and many other items. Analysis of hemoglobin in sickle cell trait , anemia, and normal was very exciting.
Some people are blood type B but behave as O .
As genetics and biochemistry move closer together they become more sophisticated. For example they can explain many more phenomena at the more elementary level. Analysis of yellow and agouti mice presented a useful and ever present problem in genetic analysis. Epistasis and Genetic Interactions are very important in genetics. The basis for modified dihybrid ratios is due to interactions of two different gene pairs.