Telomere

Definition

Telomeres are repetitive nucleotide sequences at the ends of linear chromosomes that protect them from degradation and prevent fusion with neighboring chromosomes. They play a critical role in maintaining genomic stability during DNA replication.

5 Must Know Facts For Your Next Test

1. Telomeres shorten with each cell division, leading to cellular aging and eventual cell death.
2. The enzyme telomerase can extend telomeres, allowing cells to divide beyond their normal limit.
3. In many cancer cells, telomerase is abnormally active, enabling limitless replication.
4. Telomere length is a biomarker for aging and age-related diseases.
5. Telomere shortening can lead to chromosome end-to-end fusions, resulting in genomic instability.

Review Questions

• What role do telomeres play in protecting chromosomes during DNA replication?
• How does the enzyme telomerase affect telomere length?
• Why is abnormal activation of telomerase significant in cancer cells?

Related terms

Chromosome: A structure composed of DNA and proteins that contains genetic information.

DNA Replication: The process by which a cell duplicates its DNA before cell division.

Telomerase: An enzyme that adds nucleotide sequences to the ends of telomeres, extending their length.