Viroids are tiny molecules of circular RNA that are important infectious agents of which of the following?

• A. Bacteria
• B. Plants
• C. Animals
• D. Fungi

Answer: (B)

Verified step by step guidance

1. Understand what viroids are: Viroids are small, circular RNA molecules that lack a protein coat and are known to cause diseases.
2. Recall the types of organisms that viroids infect: Viroids are unique because they infect plants, not animals, bacteria, or fungi.
3. Recognize that viroids do not have the machinery to infect bacteria or animals, as these organisms require different types of infectious agents like viruses or bacteria themselves.
4. Note that viroids cause diseases in plants by interfering with their normal gene expression and metabolism.
5. Conclude that among the given options, viroids are important infectious agents specifically of plants.