How Do Alleles Determine Traits in Genetics?
Definition: An allele is an alternative form of a gene (one member of a pair) that is located at a specific position on a specific chromosome . These DNA codings determine distinct traits that can be passed on from parents to offspring through sexual reproduction . The process by which alleles are transmitted was discovered by scientist and abbot Gregor Mendel (1822–1884) and formulated in what is known as Mendel's law of segregation . Dominant and Recessive Alleles Diploid organisms typically have two alleles for a trait. When allele pairs are the same, they are homozygous . When the alleles of a pair are heterozygous , the phenotype of one trait may be dominant and the other recessive. The dominant allele is expressed and the recessive allele is masked. This is known as complete genetic dominance . In heterozygous relationships where neither allele is dominant but both are completely ...