Alleeliparit

Alleeliparit (allele pairs) are the two versions of a gene that occupy the same locus on homologous chromosomes. In diploid organisms, an individual inherits one allele from each parent, forming a pair. The combination of the two alleles constitutes the genotype, while the observable trait produced by the gene is the phenotype. Depending on the relationship between the alleles, phenotypes may show complete dominance (one allele masks the other), codominance (both alleles contribute), or incomplete dominance (a blending of traits).

Common terms include homozygous (two identical alleles, e.g., AA or aa) and heterozygous (two different alleles, e.g., Aa). The study of allele pairs informs inheritance patterns such as Mendelian traits, as well as more complex modes of inheritance.

During meiosis, homologous chromosomes separate so that gametes receive one allele from each pair. Random fertilization combines allele pairs from two parents, generating genetic diversity. Allele frequencies in a population—the frequency of particular alleles across individuals—affect evolutionary change over generations.

Mutations can create new alleles, expanding the set of possible allele pairs. Gene interactions, epistasis, and linkage can influence how allele pairs affect traits, beyond simple dominant-recessive models. In genomics and medical testing, distinguishing allelic variants and their pairing is essential for interpreting genetic risk, trait expression, and diagnostic results.

Alleeliparit remain a central concept in genetics, helping explain how genetic information is inherited and manifests across generations.