Telomeres are located at the ends of chromosomes. They consist of multiple repeat sequences and their main function is to ensure that when DNA is replicated, the ends of the molecule are included in the replication and not left out. When teaching the significance of telomeres, I use Lego to build giant chromosomes as this allows me to demonstrate the loss of a short section of each telomere during cell division (by removing Lego bricks) and the role of telomerase in replenishing it (by adding Lego bricks).