Question

In relation to oncogenes, ____ ____ ____ mutant alleles are recessive, so both copies of the tumor suppressor must be inactivated.

Answer 1

Tumor suppressor genes are generally recessive and both alleles must be inactivated for oncogenesis. The p53 gene is a significant example; when mutated, it leads to a lack of control over cell division and contributes to cancer development.

Step-by-step explanation:

In relation to oncogenes, mutant alleles are generally recessive, so both copies of the tumor suppressor must be inactivated.

Tumor suppressors function to prevent excess, inappropriate cell growth and these functions are often disabled in cancer cells.

Mutated tumor suppressors can lead to cancer by failing to properly regulate cell growth, allowing cells to divide uncontrollably.

For instance, the most studied tumor-suppressor gene, p53, is mutated in over 50% of all cancers and plays a critical role in controlling cell division and apoptosis. When both alleles of a tumor suppressor gene like p53 are mutated, the regulatory 'brakes' on cell division are released, contributing to the development of cancer.