â¢ TORNADO (noun). The noun TORNADO has 2 senses: 1. a localized and violently destructive windstorm occurring over land characterized by a funnel-shaped cloud extending toward the ground. 2. a purified and potent form of cocaine that is smoked rather than snorted. Familiarity information: TORNADO used as a noun is rare.
In other words, nothing is different about the way these alleles are inherited; the only difference is in the way the alleles determine phenotype when they are combined. As opposed to partial dominance, codominance occurs when the phenotypes of both parents are simultaneously expressed in the same offspring organism.
When both alleles are present, they are both expressed in the phenotype. The hybrid is a blend of both alleles. Alleles which are equally strong are said to be incomplete dominant alleles. An example of this is found in carnations. When purebred white carnations are crossed with purebred red carnations, the result is a pink carnation. Incomplete dominant alleles are represented by different capitalized letters. Codominance, is a situation in which both alleles are equally stong and both alleles are visible in the hybrid genotype. An example of codominance is found in chickens. When white chickens are crossed with black chickens, the result is not a grey chicken, but a chicken with both black and white feathers. When expressing incomplete alleles, both alleles are written as superscipt capital letters placed above the letter i.