Unveiling the Masked Allele: Understanding Dominant and Recessive Alleles in Genetics

An allele that is masked when a dominant allele is present

In genetics, an allele refers to one of the different forms of a gene that exist at a specific locus (position) on a chromosome

In genetics, an allele refers to one of the different forms of a gene that exist at a specific locus (position) on a chromosome. Alleles can be either dominant or recessive, which determines how they are expressed in an organism.

When an allele is described as being masked when a dominant allele is present, it means that the presence of the dominant allele prevents the expression or phenotypic manifestation of the other allele, also known as the recessive allele. In this case, the dominant allele “masks” the effects of the recessive allele.

Let’s consider a specific example to understand this concept better. The gene for eye color in humans has multiple alleles, with the dominant allele being responsible for brown eye color (B) and the recessive allele for blue eye color (b).

If an individual has two alleles for brown eyes (BB), the dominant allele (B) is expressed, and the person will have brown eyes. In this case, the recessive allele (b) is masked and does not affect the phenotype.

However, if an individual has one dominant allele (B) and one recessive allele (b) (Bb), the dominant allele (B) still masks the effects of the recessive allele (b). Therefore, the person will have brown eyes, as the dominant allele overrides the expression of the recessive allele.

The recessive allele (b) would only be expressed when an individual carries two copies of the recessive allele (bb). In this case, the presence of the dominant allele (B) is absent, and the recessive allele (b) is expressed, resulting in the individual having blue eyes.

In summary, an allele that is masked when a dominant allele is present refers to a recessive allele that is not expressed or visible in the presence of a dominant allele.

More Answers: