Dominanzgraden

Dominanzgraden is a term used in genetics to describe the extent to which one allele masks the expression of another allele at the same locus. This concept is central to understanding Mendelian inheritance patterns. When an individual inherits two different alleles for a particular gene, the allele that is expressed and determines the phenotype is called dominant, while the allele whose expression is masked is called recessive.

The degree of dominance can vary. Complete dominance occurs when the dominant allele completely masks the effect of the recessive allele, resulting in the same phenotype whether one or two copies of the dominant allele are present. Incomplete dominance, on the other hand, results in a blended phenotype. For example, if a red flower allele and a white flower allele are incompletely dominant, offspring with one of each allele might have pink flowers.

Codominance is another form of dominance where both alleles are fully expressed simultaneously. An example is blood types in humans, where the A and B alleles are codominant. An individual with both A and B alleles will have AB blood type, expressing both A and B antigens. Understanding the degree of dominance is crucial for predicting the inheritance of traits and for analyzing genetic crosses. It influences how genotypes translate into observable phenotypes.