Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells? a. Proto-oncogenes first arose from viral infections. b. Proto-oncogenes are mutant versions of normal genes. c. Proto-oncogenes are genetic 'junk.' d. Proto-oncogenes normally help regulate cell division.

Key Concepts

Proto-oncogenes

Proto-oncogenes are normal genes that play a crucial role in regulating cell growth and division. They encode proteins that help control the cell cycle and promote cell proliferation. When these genes undergo mutations or are overexpressed, they can become oncogenes, leading to uncontrolled cell division and cancer.

Oncogenes

Oncogenes are mutated or abnormally expressed versions of proto-oncogenes that contribute to the development of cancer. They can promote excessive cell division or inhibit normal cell death, resulting in tumor formation. Understanding the transition from proto-oncogenes to oncogenes is essential for grasping how cancer develops at the molecular level.

Cell Cycle Regulation

The cell cycle is a series of phases that a cell goes through to grow and divide. Proper regulation of this cycle is vital for maintaining healthy cell function and preventing cancer. Proto-oncogenes are integral to this regulation, as they produce proteins that ensure cells divide only when necessary, highlighting their importance in preventing tumorigenesis.