Question

Is it possible that the dominant allele exists in a lower frequency than the recessive allele? Explain.

Answer 1

The dominant phenotypes are not always more frequent than the recessive phenotypes

Let us examine a typical (thus rare) character of a single gene:

dominant allele + dominant allele = dominant phenotype

dominant allele + recessive allele = dominant phenotype

recessive allele + recessive allele = phenotype Recessive

Looking at this, you might conclude that the dominant phenotype is more common. But recessive alleles could be present in a high frequency in a certain population.

For example: in the color of the eyes, people with clear eyes tend to carry recessive alleles of key genes. Dark-eyed people tend to have dominant alleles.

In Scandinavia, most people have clear eyes, implying that recessive alleles of these genes are much more common in this region than dominant alleles.