Question

Define oncogenes and name one disease caused by their activation.

Hint:

{Proto-oncogene → Mutation → Oncogene → Cancer} Example disease: Leukemia.

Answer 1

Definition of Oncogenes:

Oncogenes are mutated or altered forms of normal genes called proto-oncogenes that have the potential to cause uncontrolled cell growth and division. Proto-oncogenes normally play an important role in regulating cell growth, cell division, and cell differentiation. However, when these genes undergo mutation or abnormal activation, they become oncogenes and can lead to the development of cancer.

In simple terms, oncogenes are genes that promote excessive and uncontrolled cell proliferation, which may result in tumor formation.

How Oncogenes Cause Disease:

1. They cause continuous stimulation of cell division.
2. They prevent normal regulation of the cell cycle.
3. They may inhibit programmed cell death (apoptosis).
4. As a result, abnormal cells multiply rapidly and form tumors.

Oncogenes can be activated by mutations, exposure to radiation, chemicals, viruses, or inherited genetic changes.

One Disease Caused by Activation of Oncogenes:
Cancer (for example, lung cancer, breast cancer, or leukemia).

For instance, mutation in the RAS gene (a well-known proto-oncogene) can convert it into an oncogene and lead to uncontrolled cell growth, which is commonly associated with various types of cancers.

Conclusion:
Oncogenes are mutated forms of proto-oncogenes that cause uncontrolled cell division and lead to cancer. One major disease caused by their activation is cancer, such as leukemia or lung cancer.