Virology Multiple Choice Questions & Answers (MCQs) focuses on “Human Viral Diseases – Prion Diseases”.
1. The prion diseases are known as _____________
a) AIDS
b) TSEs
c) Hepatitis
d) Cancer
Answer: b
Clarification: The prion diseases are collectively known as transmissible spongiform encephalopathies or TSEs. Transmissible refers to the fact that the causative agent is infectious, spongiform refers to the development of holes in the brain and encephalopathy means disease of the brain.
2. The prions contain ______________
a) nucleic acid
b) proteins
c) carbohydrate
d) fats
Answer: b
Clarification: The prion appears to be misfolded forms of normal cellular proteins. This ‘protein-only’ hypothesis was proposed by Stanley Prusiner, who also suggested the term prion, derived from infectious protein.
3. The prion protein in human is encoded by __________ gene.
a) Prnp
b) Rnp
c) Pnp
d) Ppp
Answer: a
Clarification: In humans, the protein is encoded by Prnp gene. The role of the protein is not known but it cycles between endosomes and cell surface, where it is held in the plasma membrane by a glycosyl-phosphatidyl-inositol anchor at its C terminus. It is found especially in cells of the CNS.
4. The normal protein form of prion is designated as _____________
a) PrPc
b) Prnp
c) PrPSc
d) PrPres
Answer: a
Clarification: The normal protein form of prion is designated as PrPc where PrP stands for prion protein and c stands for the cell. The normal form is easily digested by proteinase K and much of the conformation is α-helix.
5. Which of the following is the prion disease of sheep and goats?
a) Scrapie
b) Cancer
c) Encephalopathy
d) Tumor
Answer: a
Clarification: Scrapie is the prion disease of sheep and goats. This disease has been known in Britain and other parts of Europe for hundreds of years. Scrapie can be transmitted from sheep to sheep by injection of brain tissue.
6. Bovine Spongiform Encephalopathies was first reported in _____________
a) 1999
b) 1980
c) 1986
d) 1988
Answer: c
Clarification: Bovine Spongiform Encephalopathies (BSE) was first reported in 1986 in the United Kingdom. The disease spread by feeding meat and bone meal to cattle as a protein supplement.
7. Which of the following is a spontaneous human prion disease?
a) Sporadic CJD
b) Kuru
c) Insomnia
d) Familial CJD
Answer: a
Clarification: Sporadic Creutzfeldt-Jakob disease (CJD) is the spontaneous human prion disease and is the most common occurring throughout the world. It may lead to dementia and death.
8. Which of the following is an acquired prion disease in humans?
a) Familial CJD
b) Insomnia
c) vCJD
d) Scrapie
Answer: c
Clarification: vCJD (Creutzfeldt-Jakob disease) is an acquired prion disease in humans. It had resulted from humans ingesting BSE prion. Many pieces of evidence came from the laboratory studies that BSE is the causative agent of vCJD.
9. FSE is the prion disease of domestic cats.
a) True
b) False
Answer: a
Clarification: Feline spongiform encephalopathy (FSE) is the prion disease of domestic cats. It affects the brain of felines. The disease is invariably fatal and is caused by the same agent that causes BSE in cattle.
10. GSS is the disease of _____________
a) rats
b) humans
c) cattle
d) mink
Answer: b
Clarification: Gerstmann-Straussler-Scheinker (GSS) is the disease of humans. It is a fatal neurodegenerative disease that affects patients from 20 to 60 years of age. It causes deterioration of mental function and loss of coordination.
11. PrPres is the designated form of the misfolded prion protein.
a) True
b) False
Answer: a
Clarification: PrPres is the designated form of the misfolded prion protein. It is also designated as PrPSc and this form of protein is largely resistant. In prion disease the misfolded form of the protein remains intact and aggregate as fibrils, rods or other forms, depending on the host and the prion strain.