[Campbell Biology P.437] Proto-oncogenes, which normally stimulate cell growth and division,... | Practice Question

Proto-oncogenes, which normally stimulate cell growth and division, can become oncogenes through various genetic changes. Which of the following is NOT described in the text as a primary mechanism for this conversion?

  • A: Epigenetic changes, such as altered chromatin condensation.
  • B: Translocations, where a proto-oncogene is moved near an active promoter.
  • C: Gene amplification, increasing the number of proto-oncogene copies.
  • D: Point mutations in the proto-oncogene's coding sequence leading to a more active protein.
  • E: Direct viral integration into the proto-oncogene sequence, immediately rendering it non-functional.

Explanation

The text clearly lists four main categories of genetic changes that convert proto-oncogenes to oncogenes: epigenetic changes, translocations, gene amplification, and point mutations. While viruses can carry oncogenes, direct viral integration leading to a proto-oncogene becoming immediately non-functional is not one of the four described mechanisms for the conversion of cellular proto-oncogenes.