Similarities and Differences between Viruses, Viroids, Satellites, and Prions

What are viruses composed of?

Viruses are composed of nucleic acid (DNA or RNA) enclosed in a protein coat called a capsid, and sometimes a lipid envelope.

What are viroids composed of?

Viroids are composed solely of a short strand of circular, single-stranded RNA without a protein coat.

What are satellites composed of?

Satellites are composed of nucleic acid (either DNA or RNA) and require a helper virus to replicate.

What are prions composed of?

Prions are composed solely of misfolded proteins with no nucleic acid.

Do viruses need a host cell to replicate?

Yes, viruses require a host cell's machinery to replicate.

Do viroids need a host cell to replicate?

Yes, viruses require a host cell's machinery to replicate.

Do satellites need a host cell to replicate?

Yes, satellites need a host cell and a helper virus to replicate.

Do prions need a host cell to replicate?

No, prions propagate by inducing normal proteins in the host to misfold into the prion form.

Which of the following are considered infectious agents: viruses, viroids, satellites, or prions?

All four (viruses, viroids, satellites, and prions) are considered infectious agents.

Which infectious agent contains both proteins and nucleic acids?

Viruses contain both proteins and nucleic acids.

Which infectious agents lack a protein coat?

Viroids and prions lack a protein coat.

What is a unique feature of prions compared to other infectious agents?

Prions are infectious proteins that cause diseases by altering the conformation of normal proteins.

How do satellites differ from viruses in terms of replication?

Satellites require a helper virus to replicate, whereas viruses can replicate independently within a host cell.

What type of organisms do viroids typically infect?

Viroids typically infect plants.

What type of organisms do prions typically affect?

Prions typically affect animals, including humans.

Can viruses cause diseases in humans, plants, and animals?

Yes, viruses can cause diseases in humans, plants, and animals.

What are some diseases caused by prions?

Diseases caused by prions include Creutzfeldt-Jakob disease (CJD) and mad cow disease (bovine spongiform encephalopathy).

Are viroids known to cause diseases in humans?

No, viroids are not known to cause diseases in humans; they primarily cause diseases in plants.

How do satellites differ from viroids in terms of dependency?

Satellites depend on a helper virus for replication, while viroids do not depend on other viruses.

How do prions propagate within the host organism?

Prions propagate by converting normal, cellular proteins into the misfolded prion form.

What is the structural difference between viruses and prions?

Viruses have nucleic acids encased in a protein coat, whereas prions are composed only of proteins.

What is the main similarity between all four (viruses, viroids, satellites, and prions)?

They are all infectious agents that can cause diseases in their respective hosts

What distinguishes viroids from viruses in terms of structure?

Viroids lack a protein coat and are composed only of a short strand of RNA.

What distinguishes prions from viruses, viroids, and satellites in terms of their genetic material?

Prions do not contain any genetic material (DNA or RNA); they are solely composed of protein.