PATHOLOGY

Detailed explanation-1: -Dominant and recessive genes. The most common interaction between alleles is a dominant/recessive relationship. An allele of a gene is said to be dominant when it effectively overrules the other (recessive) allele. Eye colour and blood groups are both examples of dominant/recessive gene relationships.

Detailed explanation-2: -A recessive allele does not produce a trait at all when only one copy is present. This contrasts to a dominant trait, which requires that only one of the two alleles be present to express the trait.

Detailed explanation-3: -Examples of Dominant Traits Curly hair is dominant over straight hair. Baldness is a dominant trait. Having a widow’s peak (a V-shaped hairline) is dominant over having a straight hairline. Freckles, cleft chin and dimples are all examples of a dominant trait.

Detailed explanation-4: -Dominant alleles are seen as an uppercase of a letter; for example, B. Recessive alleles are seen as a lower case of a letter; b. In order for a person to show the dominant trait, one of the person’s parents must have the dominant trait (which is an uppercase letter).