On the distinction between chromosomes no. 21 and no. 22 by the C-banding pattern.
D002869:Chromosome Aberrations; D002904:Chromosomes, Human, 21-22 and Y; D006801:Humans; D007621:Karyotyping; D011110:Polymorphism, Genetic; D013194:Staining and Labeling; D014314:Trisomy