Banded human karyotype
Arranged by size. Smaller chromosomes are not drawn at the same scale as the larger. Note the position of the centromere between the short and long arms of the chromosomes, the presence of constitutive heterochromatin that stains darkly and is not expressed genetically, and the occurrence of duplicated loci on the short arms of chromosomes 13, 14, 15, 21, & 22 for ribosomal DNA (rDNA)
Figure © 2012 TA Brown, Introduction
to Genetics (1st ed.); additional
text © 2016 by Steven M. Carr