What is incomplete dominance?
Incomplete dominance or mixing of inheritance is a term used in genetics when two different alleles in one gene show dominance in the resulting phenotype, an observable feature or characteristic. Incomplete dominance is not synonymous with codominance, where two seemingly dominant alleles contribute separate characteristics. In incomplete dominance, two genotypes of alleles mix their phenotypes into a significant third.
alleles are different versions of the same genes. They can be dominant, recessive, codominant or incompletely dominant. Normally there are two alleles on the gene, each parent contributes to descendants. Alleles determine the physical properties or phenotypes of living organisms.
genes can be homozygous, which means they carry a few identical alleles or heterozygous, which means they carry different alleles. Many alleles are either dominant or recessive, so if the gene has a dominant allele, the phenotype shows the dominant characteristic whether the gene is homozygous or heterozygous. Recessive genes will only be exposed toIf the gene is homozygous for recessive alleles. Alleles must also not be dominant or recessive, as in case of incomplete dominance and codominance. However, incomplete dominance and codominance are observed only in heterozygous genes, because the gene must have two different alleles to share dominance between them.
For example, if the flower has a dominant allele for red petals and recessive allele for petals made of white colored petals, flower petals will be red. In alleles that show incomplete dominance, neither the red nor the white allele will be recessive or dominant, and instead, if the flower is heterozygous, the features mix together and create pink petals. This is a different phenomenon from Kodominance, which would create a flower with red and the petals.
, however, it is important to realize that the alleles themselves are not allowed to create a third type of allele, only the resultingFenotypes of mixtures. In cases such as color, geneticists believe that these resulting phenotypes are caused by pigment production. If red alleles always tell the plant to produce red pigments and white alleles lack any pigment production orders, flowers with two red alleles will be darker than those with only one.
In humans, the incomplete dominance is to be seen in many features such as stretching lips, spacing of male voices and hair type. For example, if one parent has completely straight hair and one parent has curly hair, the resulting child will not have straight or curly hair, but instead a mixture of these two: wavy hair. Diseases such as Tay-Sachs may also be controlled by incomplete dominance. The gene that produces antibodies of Tay-Sachs creates only half of these antibodies in heterozygous individuals compared to shomozygous individuals, leaving heterozygous children susceptible to the disease.