Dominant alleles are always expressed, regardless of what the other allele is that a person has. Recessive alleles are only expressed if both of a person's alleles are recessive. If a person has one dominant allele and one recessive, he is called a carrier . An example of this is albinism. Albinism is a condition where a person does not produce any melanin, the protein that gives color to our skin, hair and eyes.
Classic albinism is a recessive allele.
If a person gets the albino trait from only one of his parents, he does not express the albino condition and is considered a carrier. This is how someone can pass on a trait that, he does not appear to have. Albinism is an example of a common type of inheritance called autosomal recessive inheritance. These conditions have an equal chance of appearing in both males and females. Each cell that will make the baby must have exactly 23 chromosomes.