Question

All are oncogenic viruses except?
A. Influenza virus
B. Hep. B virus
C. HIV
D. V. Zoster

Answer 1

Hint: Oncogenic viruses are viruses that cause cancer. These viruses can induce tumors, as they cause transformation and infect cultured cells. Oncogenic viruses are those that are suspected of causing cancer in human beings and some other animals.

Complete answer: The characteristics of oncogenic viruses are discussed below:
The viruses are having an inert crystalline structure outside the living cell and are non-cellular organisms. The genetic material of viruses is either RNA or DNA. A virus contains the genetic material which is infectious and a protein coat that protects the nucleic acid is called a capsid and is made up of small subunits called capsomeres.
Normal cells possess a property of contact inhibition which inhibits their uncontrolled growth when contact with other cells. Cancer cells appear to have lost this property. Hence, cancerous cells give rise to masses of cells called tumors by dividing continuously.
Various physical, chemical, or biological agents induced the transformation of normal cells into cancerous or neoplastic cells. These agents are called carcinogens. Neoplastic transformation is induced by ionizing radiations like X-rays and gamma rays and non-ionizing radiations like UV cause DNA damage. Tobacco smoke is a chemical carcinogen that is a major cause of lung cancer.
Oncogenic viruses have genes called viral oncogenes which cause cancer. Proto-oncogenes or cellular oncogenes (c-onc) are some genes that have been identified in normal cells which when activated under certain conditions, could lead to oncogenic transformation of the cells. Viruses cause diseases like mumps, smallpox, hepatitis B, herpes, and influenza. AIDS in humans is also caused by the HIV virus. So, Zoster is the only virus that doesn’t cause cancer, hence not oncogenic.

Thus, the correct answer is Option D, V. Zoster.

Note:
> Tumors are of two types: benign and malignant. Benign tumors do not spread to other parts of the body and normally remain confined to their original location hence causes little damage.
> The mass of proliferating cells called neoplastic or tumor cells is called malignant tumors. These cells invade and damage the surrounding normal tissues very rapidly. This property of malignant tumors is called metastasis which is the most feared property.