AP BIOLOGY

Detailed explanation-1: -The synthesis of telomeres is mainly achieved by the cellular reverse transcriptase telomerase, an RNA-dependent DNA polymerase that adds telomeric DNA to telomeres. Expression of telomerase is usually required for cell immortalization and long-term tumor growth.

Detailed explanation-2: -Telomeres, repetitive (TTAGGG) DNA–protein complexes at the ends of chromosomes, are crucial for the survival of cancer cells. They are maintained by an enzyme called telomerase in the vast majority of tumors.

Detailed explanation-3: -Telomeres – which are the DNA repeats that form the tips of chromosomes and are produced by the telomerase enzyme – play a crucial, and curious, role in the life of the cell.

Detailed explanation-4: -Some cells have the ability to reverse telomere shortening by expressing telomerase, an enzyme that extends the telomeres of chromosomes. Telomerase is an RNA-dependent DNA polymerase, meaning an enzyme that can make DNA using RNA as a template.

Detailed explanation-5: -Telomerase-the enzyme responsible for protecting chromosome ends from shortening during DNA replication to avoid potentially catastrophic DNA loss-is an RNP composed of the telomerase reverse transcriptase (TERT) protein and the telomerase RNA (TR) among other constituents.