Question

Which of the following statements about Proto-oncogenes and Antioncogenes is NOT true?

(A) Antioncogenes are often called Tumor Suppressor Genes
(B) Proto-oncogenes typically code for cell-cycle related proteins.
(C) Even one functional copy of an antioncogene is typically enough to inhibit tumor formation.
(D) Oncogenes could be described as speeding up the cell cycle, and antioncogenes are like cutting the brakes.

Answer 1

The statement that is incorrect is (C) since both copies of a tumor suppressor gene must typically fail to prevent tumor formation. Proto-oncogenes and tumor suppressor genes are the cell cycle's critical regulators.

Step-by-step explanation:

The statement about Proto-oncogenes and Antioncogenes that is NOT true is (C) Even one functional copy of an antioncogene is typically enough to inhibit tumor formation. This statement is inaccurate because typically, both copies of a tumor suppressor gene (antioncogene) must be nonfunctional for tumor formation to progress. Mutations that lead to a loss of function in both allelic copies are what lead to the loss of tumor-suppressive activities.

Proto-oncogenes code for proteins that promote cell division and are critical to normal cell function. When these genes are mutated, they can become oncogenes, which may lead to uncontrolled cell division. On the other hand, tumor suppressor genes, often referred to as antioncogenes, produce proteins that can stop cell division, repair DNA errors, or initiate apoptosis (programmed cell death). The balance between the activity of proto-oncogenes and tumor suppressor genes is vital for normal cell cycle regulation.