resessiivisiin

Resessiivisiin refers to the Finnish adjective "resessiivinen," meaning "recessive" in the context of genetics and hereditary traits. A recessive trait or allele only expresses itself in an organism when two copies of that allele (one from each parent) are present. If at least one dominant allele is present, the recessive characteristic is typically masked. The opposite of a recessive allele is a dominant allele, which will manifest in the phenotype even when only one allele is present.

In Mendelian genetics, the classic example of a recessive trait is the blue eye color in humans. Another example is cystic fibrosis in humans or the blue flowers in the Mendelian pea plant, which are only observed when the recessive allele is homozygous. Recessive genes can persist in a population because they may confer advantages under certain circumstances, such as increased resistance to a disease, while remaining hidden in carriers. When two carriers reproduce, there is a 25 % chance that their offspring will express the recessive trait.

The study of recessive inheritance has important medical and agricultural implications. Clinicians use knowledge of recessive patterns to assess the risk of genetic disorders, and breeders exploit recessive allele information to develop desirable plant and animal varieties. Recessive alleles also exemplify key evolutionary concepts such as genetic drift, selection, and population structure, making them a central topic in the study of heredity.