Are recessive alleles harmful?

Recessive alleles

1. Different versions of a gene are called alleles.
2. Alleles can be dominant or recessive based on their expression.
3. Recessive alleles show their effect if the individual has two copies of the same allele.
4. Inheritance of one brown allele and one blue allele for eye color from each parent will result in brown eyes in the offspring.
5. The blue eye color allele is an example of a recessive allele. That means it won't show up in you unless you get blue-eyed alleles from both parents.
6. Similarly, the presence of two recessive alleles for a character can result in disease.
7. Examples- colorblindness, sickle cell anemia, etc.
8. Thus, the presence of recessive alleles always need not be harmful.