B.SC.1 YEAR,BOTANY

1. VIROIDS,VIRUSOIDS&PRIONS
Presented
By
Kanchan Sinha
ShriShankaracharyaMahavidyalaya,Junwani,Bhilai

4. Virion
1. Virion is a complete functional virus that has
the capacity to infect living tissue.
2. It includes the genetic material either RNA or
DNA, capsid, envelope and membrane proteins.
3. Membrane proteins allow the virus to bind to
its host and enter it.

5. Viroid
Viroid is smaller than virus.
2. Viroid is single stranded covalently closed
infectious RNA molecule without capsid.
3. They replicate by RNA-RNA transcription
and lack protein coding.
4. Viroids only infect plants.

9. Prions
• Prions are “infectious proteins”
• They are normal body proteins that get converted into an alternate
configuration by contact with other prion proteins
• They have no DNA or RNA
• The main protein involved in human and mammalian prion diseases is
called “PrP”

12. REFERENCES
• https://www.slideshare.net/sabertooth89/viriods-and-prions
• https://www.slideshare.net/maylowen13/virus-viroids-and-prions
• https://medium.com/@nehamicrobio83/difference-among-virus-
virion-viroid-virusoid-and-prion-a01f22f06825