A proto-oncogene is an allele of a gene that produces a protein with normal activity. True False
The correct answer and explanation is:
Answer: True
Explanation:
A proto-oncogene is a normal gene that codes for proteins involved in cell growth, division, and differentiation. These proteins play essential roles in regulating normal cellular functions such as signaling pathways that control when a cell should divide or when it should die. Proto-oncogenes produce proteins with normal activity that help maintain healthy cell function.
However, when a proto-oncogene undergoes mutations or becomes abnormally activated—due to genetic changes like point mutations, gene amplification, or chromosomal rearrangements—it can become an oncogene. Oncogenes produce altered proteins that have increased or unregulated activity, which can lead to excessive cell division and potentially contribute to the development of cancer.
In simpler terms:
- Proto-oncogene: The normal, healthy version of a gene, producing normal proteins that regulate cell growth.
- Oncogene: The mutated or overactive form of that gene, producing abnormal proteins that can cause uncontrolled cell proliferation.
For example, the proto-oncogene RAS normally produces a protein that acts as a molecular switch in cell signaling pathways controlling growth. When mutated, RAS becomes an oncogene that continuously signals the cell to divide, contributing to cancer development.
In summary, the statement is true because a proto-oncogene is indeed an allele of a gene that produces a protein with normal activity. It only becomes dangerous when it mutates into an oncogene.