In cells where telomerase is normally inactive, it can become active by accident and often, cancer will develop as a result. Can
cer typically occurs when cells undergo DNA replication and division more frequently than is required by the organism for survival. This leads to growth of cancerous tumors. Using what you learned about telomerase in this video and this lesson, predict how telomerase activity can lead to cancer.
Cancer cells achieve proliferative immortality by activating or upregulating the normally silent human TERT gene (hTERT) that encodes telomerase, a protein with reverse transcriptase activity that complexes with other proteins and a functional RNA (encoded by hTR, also called hTERC) to make a ribonucleoprotein enzyme.
Explanation:
A rare cell that escapes crisis almost universally does so by reactivating telomerase and this cell can now become a cancer cell with limitless potential to divide. Almost all cancer cells have short telomeres and thus inhibitors of telomerase should drive such cancer cells into apoptotic cell death. Yet, each time a cell divides, the telomeres get shorter. When they get too short, the cell no longer can divide and becomes inactive or "senescent" or dies. This process is associated with aging, cancer, and a higher risk of death.
Mitosis is the type of division that occurs in the general body cells resulting in growth while meiosis is the process that occurs during the formation of sex cells. Mitosis results in two daughter that are identical to one another and to the parent cell. In meisosis there is crossing over during prophase I.
