The proportion of the DNA of a eukaryotic cell that consists of copies of nucleotide sequences, often in large numbers. For example, in humans these sequences can vary in length from 5 to over 300 bp, which are repeated in tandem 105 to 106 times. It occurs mainly around the centromeres and telomeres of the chromosomes. The highly repetitive nature of this DNA fraction gives it a distinctive base composition, and consequently when samples of DNA are centrifuged it forms so-called ‘satellite bands’ quite separate from the band representing the bulk of the cell’s DNA. See repetitive DNA. Compare microsatellite DNA; variable number tandem repeats.