Practice question

Alleles are alternative forms of the same gene arising by mutation at a common locus on homologous chromosomes. They retain same position and general function but differ in nucleotide sequence, producing phenotypic variants such as tall versus dwarf alleles of pea height gene. In diploid individuals two alleles coexist, identical in homozygote or different in heterozygote, and segregate during meiosis. Different genes occupy distinct loci, identical copies lack variation, and non-functional DNA segments do not constitute allelic series within gene pool. Understanding this mechanism aids pedigree analysis, Punnett predictions, linkage mapping and appreciating evolutionary conservation across taxa.