title: Sister chromatid exchanges in a ring chromosome 4.
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D002648:Child; D002842:Chromatids; D002905:Chromosomes, Human, 4-5; D006801:Humans; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008938:Mitosis