What are virus viroids and prions?
Viroids consist of small, naked ssRNAs that cause diseases in plants. Virusoids are ssRNAs that require other helper viruses to establish an infection. Prions are proteinaceous infectious particles that cause transmissible spongiform encephalopathies. Prions are extremely resistant to chemicals, heat, and radiation.
What is viroids and prions Slideshare?
Viroids differ from viruses in that viruses, at their most basic level, consist of genetic material (DNA or RNA) contained within a protective protein shell. Viroids differ from prions, another type of subviral infectious agent, in that prions are made only of protein, lacking nucleic acid.
Are viruses viroids and prions alive?
Viruses, viroids, and prions are not technically living things. However, with the assistance of a host cell to reproduce, these infectious agents can attack various systems in humans, plants, and animals.
Do viruses viroids and prions have ribosomes?
Without a host cell, viruses cannot carry out their life-sustaining functions or reproduce. They cannot synthesize proteins, because they lack ribosomes and must use the ribosomes of their host cells to translate viral messenger RNA into viral proteins.
What is the difference between viroids and prions?
Prions are infectious particles that contain no nucleic acids, and viroids are small plant pathogens that do not encode proteins.
What is the difference between virus and viroids?
Hint: Both the virus and viroids are infectious agents and nonliving until they invade a live host cell. They differ based on the type of their genetic material and the target cells they infect….
| Features | Virus | Viroid |
|---|---|---|
| Protein | It manufactures proteins and enters the host cell. | Viroid RNA does not code for any proteins. |
How are viruses and prions different?
Prions are smaller than viruses and can only be seen through an electron microscope when they have aggregated and formed a cluster. Prions are also unique in that they do not contain nucleic acid, unlike bacteria, fungi, viruses, and other pathogens.
Who discovered viroid?
Dr. Theodor 0. Diener
The pathogen is called a viroid by its discoverer, Dr. Theodor 0. Diener, to distinguish it from a virus.
How are viruses different from viroids?
>Viroids are different from viruses in many ways: >Viroids do not have an outer envelope or the capsid but in viruses, they only reproduce within the host cell. Viroids consist of nucleic acid without any protein coat but on the other hand, viruses composed of the nucleic acid with a coat of protein.
How are viruses and viroids different?
Why are viroids different from viruses?
Viroids differ from viruses on six points : They exist inside the cells as RNA particles only, without capsid nor envelope. They have only one circular RNA strand which contains very little nucleotides. Unlike certain viruses, viroids do not need the help of a virus to infect a cell.
What is the mode of transmission of viroid disease?
Transmission • Viroid infections are transmitted by cross contamination following mechanical damage to plants as a result of horticultural or agricultural practices. • Some are transmitted by aphids and they can also be transferred from plant to plant by leaf contact.
What are the characteristics of a viriod?
VIROIDS • Mostly plant pathogens • Consists solely of small single- stranded circular RNA molecule having 250-370 nucleotides long. • The RNA of a viriod doesn’t encode any gene products; so they can’t replicate themselves.
What is prion protein?
PRIONS • Prions are infectious agents composed primarily of sialoglycoprotein. • This protein is called prion protein (PrP) • They contain no nucleic acid. • They cause a variety of neurodegenerative diseases in humans and animals.
What is rotavirus and what are its symptoms?
Rotaviruses cause enteric disease with symptoms characterized by diarrhea, vomiting, abdominal discomfort, and fever, or any combination. The virus affects mainly infants and young children. Diarrhea ranges from mild to severe and can cause fatal dehydration. 1. VIRUSES, VIROIDS and PRIONS 2. VIRUS • Generally are quite small, 20-300 nm.