It means you have the genetics for the trait but you do not express the trait. Someone who is a carrier could not have a disease, but have offspring that does have that disease. This is because of alleles, which can be upper or lower case letters, upper being dominant traits and lower being recessive. Many genetic diseases are recessive so if a person has the genotype Rr they will carry the disease but if they have rr they will have the disease. If I were you id research how punette squares work
