Question

Infectious proteins are present in?

• A. Gemini viruses
• B. Viroids
• C. Prions
• D. Satellite viruses

Answer 1

The correct option is C

Prions

The correct option is option C.

Explanation of the correct option:

1. Infectious proteins are present in prions, they are entirely composed of proteins and folds to produce a specific structure.
2. A prion is a type of protein that can trigger normal proteins in the brain to fold abnormally.
3. Prion diseases can affect both humans and animals and are sometimes spread to humans by infected meat products.
4. The most common form of prion disease that affects humans is Creutzfeldt-Jakob disease (CJD).
5. Prion diseases occur when normal prion protein, found on the surface of many cells, becomes abnormal and clump in the brain, causing brain damage.
6. This abnormal accumulation of protein in the brain can cause memory impairment, personality changes, and difficulties with movement.
7. Several neurodegenerative diseases in animals include mad cow disease.

Explanation of the incorrect options:

Option A:

1. Gemini viruses are plant viruses that are only infectious to plants.
2. The diseases are transmitted by Phloem feeding insects.

Option B:

1. Viroids are pathogens that affect only plants.
2. They contain a single naked RNA molecule without a protein coat.

Option D:

1. Satellite viruses are pathogens that are entirely dependent on other host cells for replication purposes.

Final answer: Infectious proteins are present in prions.