Not all genes have alleles that are either dominant or recessive. In some cases, such as the color of snapdragons, the heterozygous genotype creates a new or blended phenotype. When a red and white snapdragon breed together they will produce pink flowers.
Another example of incomplete dominance deals with the shape of blood cells. The homozygous dominant genotype result in a phenotype of normal erythrocytes. The homozygous recessive genotype result in a person have sickle cell shaped blood cells (cresent) and they will have sickle cell anemia. Individuals with the heterozygous genotype have some normal cells and some sickle cell shaped cells. People with this genotype have the special advantage of being immune to malaria.
