Dominant Alleles: How They Impact Genetic Traits and Characteristics

Dominant Allele

An allele whose trait ALWAYS shows up in an organism when it is present

A dominant allele is a genetic trait that is expressed even if an individual carries only one copy of that allele in the genotype. In other words, a dominant allele masks the expression of its recessive counterpart when present in a heterozygous genotype (an organism that carries two different alleles for the same gene). Dominant alleles are usually represented by capital letters in genetics, while recessive alleles are represented by lowercase letters.

For example, the gene for brown eyes is dominant, and the gene for blue eyes is recessive. Therefore, if an individual inherits one brown eye allele and one blue eye allele, they will have brown eyes, as the dominant brown allele overrides the recessive blue allele.

Dominant alleles can play an important role in determining an organism’s physical traits and characteristics. However, it is important to note that dominant alleles do not necessarily represent the most common or desirable genetic traits and can sometimes be associated with harmful or deleterious outcomes.

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