What is the difference between virus and viroids?
| Virus | Viroids | |
| 1. | Virus was discovered by D. J. Ivanowsky in 1892 | Viroids was discovered by T.O. Diener in 1971 |
| 2. | They are larger in size than viroids | They are smaller in size |
| 3. | They possess protein coat called capsid and nucleic acid as genetic material. | They lack protein coat and exist as free RNA |
| 4. | They possess either DNA or RNA | They possess single stranded circular RNA |