Question

Assertion (A): Viroids are infectious RNA particles without a protein coat.
Reason (R): Viroids mainly infect plants and cause diseases like potato spindle tuber disease.

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is not the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Hint:

Remember:

• Virus = nucleic acid + protein coat
• Viroid = naked RNA only
• Prion = infectious protein particle

Answer 1

The Correct Option is B

Step 1: Check Assertion (A). Viroids are:

• Small infectious RNA molecules
• Lack protein coat
• Simpler than viruses

Hence Assertion (A) is true.

Step 2: Check Reason (R). Viroids infect plants and can cause diseases such as: \[ \text{Potato spindle tuber disease} \] Hence Reason (R) is also true.

Step 3: Check explanation relation. Reason (R) gives an example of disease caused by viroids, but it does not explain why viroids lack protein coat. Hence: \[ \boxed{\text{Both A and R are true but R is not the correct explanation}} \]