Question

Using the break pedal Anatoly, explain the impact on the cell cycle of one mutated tumor suppressor gene allele versus two mutated tumor suppressor alleles.

a) Slows down the cell cycle
b) Halts the cell cycle
c) Accelerates the cell cycle
d) No impact on the cell cycle

Answer 1

A single mutated tumor suppressor gene allele may not affect the cell cycle if the other allele is functional, but if both alleles are mutated, it usually accelerates the cell cycle, leading to cancer.

Step-by-step explanation:

When a single allele of a tumor suppressor gene is mutated, the cell cycle may still function normally if the other allele is unaffected and can compensate. However, if both alleles are mutated, the cell's ability to regulate division is hindered, which often accelerates the cell cycle. The uncontrolled division can lead to the proliferation of abnormal cells and the development of tumors, characteristic of cancer.

For example, the p53 protein, which acts at the G1 checkpoint of the cell cycle, serves as a 'break pedal' to halt cell division when DNA damage is detected. If the p53 gene is mutated, its capability to trigger cell repair mechanisms or apoptosis is impaired, potentially leading to unchecked cell division. In this case, the appropriate response is (c) Accelerates the cell cycle.