Final answer:
Telomeres are the ends of linear chromosomes that protect genes during cell division. When telomeres become too short, chromosome replication is compromised, leading to cell malfunction and aging.
Step-by-step explanation:
Telomeres are the ends of linear chromosomes that consist of repetitive sequences. These telomeres protect genes from getting deleted during cell division. When telomeres become too short, the chromosome can no longer be replicated properly, leading to cell malfunction and aging.