NEET2016BotanyBiological ClassificationActual
Which of the following statements is wrong for viroids?
Options
- AThey lack a protein coat
- BThey are smaller than viruses
- CThey cause infections
- DTheir RNA is of high molecular weight
Correct answer
D. Their RNA is of high molecular weight
Step-by-step solution
In viroids, RNA is of low molecular weight. Viroids, the smallest known pathogens, are naked, circular, single-stranded RNA molecules that do not encode protein yet replicate autonomously when introduced into host plants. Potato spindle tuber viroid, discovered in 1971, is the prototype; 29 other viroids have since been discovered ranging in length from 120 to 475 nucleotides. Viroids only infect plants; some cause economically important diseases of crop plants, while others appear to be benign.