Question

Bovine spongiform encephalopathyiscausedby

• A. Fungi
• B. Viroids
• C. Prions
• D. Virus

Answer 1

The Correct Option is C

The correct answer is:

Option 3: Prions

Explanation:

Bovine spongiform encephalopathy (BSE), also known as mad cow disease, is caused by prions. Prions are misfolded proteins that can induce other proteins in the brain to also misfold, leading to brain damage. This results in the characteristic "spongy" appearance of the brain tissue in affected animals.

Prions do not contain nucleic acids (DNA or RNA), which makes them distinct from viruses, bacteria, fungi, or viroids.

The other options are incorrect because:

Fungi (Option 1) cause fungal infections, not BSE.

Viroids (Option 2) are small RNA molecules that infect plants, not cows.

Viruses (Option 4) cause diseases like influenza or HIV, but not BSE.

Thus, prions are the causative agents of BSE.

Answer 2

Bovine spongiform encephalopathy (BSE), commonly known as "mad cow disease," is a fatal neurodegenerative disease in cattle. The causative agent is:

Prions

To understand why, let's look at each option in detail:

• Fungi: Fungi are eukaryotic organisms that can cause a variety of diseases, but they are not the cause of BSE.
• Viroids: Viroids are small, circular RNA molecules that infect plants. They do not infect animals.
• Prions: Prions are misfolded proteins that can induce other normal proteins to misfold in a similar way, leading to a chain reaction and the accumulation of abnormal protein aggregates in the brain. These aggregates cause the characteristic spongiform (sponge-like) appearance of the brain tissue in BSE.
• Virus: Viruses are infectious agents consisting of nucleic acid enclosed in a protein coat. While viruses cause many diseases, they are not responsible for BSE.

In detail: Prions are infectious agents composed solely of protein. In the case of BSE, the prion protein (PrP) exists in a normal, harmless form (PrPc) and a misfolded, disease-causing form (PrPsc). When PrPsc enters a healthy animal, it can convert PrPc into PrPsc, leading to the accumulation of the misfolded protein and the development of BSE.