INCOMPLETE DOMINANCE Meaning and
Definition
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Incomplete dominance is a genetic phenomenon characterized by the blending of two different alleles, resulting in an intermediate phenotype that is not completely dominant or recessive. This means that neither allele completely masks the expression of the other, thereby creating a new third phenotype.
In cases of incomplete dominance, the heterozygous genotype exhibits a distinct phenotype that is different from both homozygous genotypes. For example, if a red-flowered plant (RR) is crossed with a white-flowered plant (WW), the resulting offspring (RW) will have pink flowers, which is a blending of the red and white phenotypes.
The underlying mechanism of incomplete dominance lies in the incomplete expression of the dominant allele. Unlike complete dominance, where one allele fully masks the other, both alleles contribute to the phenotype in incomplete dominance. This may occur due to a partial loss of function in the dominant allele, resulting in a reduction of its phenotypic effect. As a result, a blending effect occurs, leading to the expression of an intermediate phenotype.
Incomplete dominance is commonly observed in traits such as flower color, hair texture, and pigment production. It is important to note that incomplete dominance does not imply a lack of dominance; instead, it represents a unique gene expression pattern where neither allele is completely dominant or recessive over the other.
Common Misspellings for INCOMPLETE DOMINANCE
- uncomplete dominance
- jncomplete dominance
- kncomplete dominance
- oncomplete dominance
- 9ncomplete dominance
- 8ncomplete dominance
- ibcomplete dominance
- imcomplete dominance
- ijcomplete dominance
- ihcomplete dominance
- inxomplete dominance
- invomplete dominance
- infomplete dominance
- indomplete dominance
- incimplete dominance
- inckmplete dominance
- inclmplete dominance
- incpmplete dominance
- inc0mplete dominance
- inc9mplete dominance
Etymology of INCOMPLETE DOMINANCE
The term "incomplete dominance" was coined by the American geneticist William E. Castle in 1913. The word "incomplete" refers to the idea that the dominant allele does not completely mask or overpower the effects of the recessive allele. Instead, both alleles contribute to the resulting phenotype, resulting in an intermediate or blended phenotype. The concept of incomplete dominance emerged through Castle's work on flower color inheritance in snapdragons, where he observed that crossing a red-flowered variety with a white-flowered variety produced pink-flowered offspring.
