title: Stages in chromosome evolution: the chromatid twins and how they grew.
mesh_terms: D001516:Bees; D005075:Biological Evolution; D002467:Cell Nucleus; D002842:Chromatids; D002875:Chromosomes; D002876:Chromosomes, Bacterial; D002901:Chromosomes, Human, 13-15; D002903:Chromosomes, Human, 19-20; D004247:DNA; D006801:Humans; D008214:Lymphocytes / Q000166:cytology; D008853:Microscopy; D008938:Mitosis
chemical_list: D004247:DNA