Overview: Locating Genes Along Chromosomes ? Mendel?s ?hereditary factors? were genes, though this wasn?t known at the time. ? The location of a particular gene can be seen by tagging isolated chromosomes with a fluorescent dye that highlights the gene. Concept 12.1 Mendelian inheritance has its physical basis in the behavior of chromosomes ? The chromosome theory of inheritance states: ? Mendelian genes have specific loci (positions) on chromosomes ? Chromosomes undergo segregation and independent assortment. ? The behavior of chromosomes during meiosis was said to account for Mendel?s laws of segregation and independent assortment. Morgan?s Experimental Evidence & Choice of Experimental Organism