VIRUS, VIROIDS, VIRUSOIDES, VIRION, and PRIONS

Virus:

• These are submicroscopic and acellular organisms 
• They are obligate intracellular parasites
• They contain either DNA or RNA

Chemical Composition:

• Nucleic acid -- (Central Core)
• Protein coat (Capsomere)

Note: An infectious viral particle is called Virion.

Viroids:

• Contain only low molecular weight RNA (Single stranded RNA) and not protein coat.
• Cause Potato Spindle Tuber disease 

 Virusoides:

• They are like viroids, but are located inside the protein coat of a true virus
• Virusoid RNA can be either circular or linear

 Prions:

• lack their own genetic material
• they consist of specific protein macro molecule, which is known as Prion protein pr Prep