Which of the following best defines an oncogene ?

Options

A. An oncogene is a dominantly expressed mutation which gives a cell a growth or survival advantage.
B. An oncogene codes for a mutated form of a protein which forms part of a signal transduction pathway.
C. An oncogene coeds for a protein which prevents the cell from undergoing apoptosis.
D. An oncogene codes for a cell cycle control protein.

Answer

A

Explanation

Oncogenes refer to genes that has the potential to cause cancer and are dominant at the cellular level. Protooncogenes are the normal genes. These genes code for proteins that are capable of stimulating cell growth and division. In normal tissues and organisms. such growthh stimulating proteins are regulated so, that growth is apppropriately limited However, mutations in these genes may result in loss of grwoth regulation, leading to uncontrolled cell proliferation and tumour development. Oncogenes are dominant, because a mutation of only on of the cells's two copies of that gene can lead to tumour formation.