Question

Which of the following statements is incorrect about viroid, viruses, or prions?

• A. Viroids lack a protein coat
• B. Viruses are obligate parasites
• C. The infective constituent in viruses is the protein coat
• D. Prions consist of abnormally folded proteins

Answer 1

The correct option is C

The infective constituent in viruses is the protein coat

The correct option is C.

Explanation for the correct option:

1. The virus is a tiny, straightforward infectious agent that reproduces solely in the living cells of microorganisms, plants, and mammals.
2. The infective constituent in the virus is its genetic material either DNA or RNA.
3. The capsid contains the genetic material of the virus, which can be either DNA or RNA or, in rare situations, a small number of enzymes.
4. Most capsids are tailored for the host organism of a given virus, however, capsid construction varies widely among viruses.

Explanations for the incorrect options:

Option A:

1. The smallest infectious agents are known as viroids, which are composed of just one strand of circular single-stranded RNA.

Option B:

1. Since they are inert outside of a host cell's environment and only become virulent when it enters the host, viruses are regarded as obligatory parasites because they lack the protein coating that protects them.
2. Thus, for it to complete its life cycle, it needs a host cell.

Option D:

1. Proteins folded improperly makeup prions, which can cause progressive neurodegenerative diseases to manifest.

Final answer: The incorrect statement is that the infective constituent in viruses is the protein coat.