Final answer:
Identical or similar DNA sequences that occur multiple times on a chromosome are known as repetitive sequences. These include duplication of gene segments and telomeres, which protect chromosome ends during cell division.
Step-by-step explanation:
Identical or similar DNA sequences that occur multiple times on a chromosome are called repetitive sequences. These sequences can play various roles in the genome, such as the protection of coding sequences at chromosome ends in the form of telomeres. For instance, human telomeres contain the repetitive six base-pair sequence TTAGGG, repeated 100 to 1000 times. Repetitive sequences can also be found throughout chromosomes, sometimes in the form of gene duplication, where a segment of DNA is repeated, creating multiple copies of genes. It's important to note that genes located on the same chromosome can be linked, meaning that their alleles tend to segregate together during meiosis.