Chromosome telomeres. Fluorescence light micrograph of human chromosomes with the ends of the chromatids highlighted in red, indicating the regions known as telomeres. This image shows that some chromosomes are depleted of telomeres, which can result in abnormal cell division and cancer. The telomere is a region of repeated non-coding nucleotides, the function of which is to prevent coding nucleotides being lost during DNA replication. Telomeres shorten over time and this process is thought to play a role in cancer and ageing.