Viruses, Prions, and Viroids

Viruses- Infection that reproduces in a host cell. Antibiotics don’t heal the infection. Vaccines may prevent the viruses, but won’t cure. EX. FLU, HIV, Polio






Prions: Infectious agent composed of proteins. EX. Creutzfeldt Jakob and Mad Cow.







Viroids: Plant pathogens contain short stretch of highly single-stranded RNA without a protein coat. EX. Potatoes and Tomatoes







Considered to be Alive??
Viruses are a parasite that need a host cell to grow, so they are “alive” because they have strands of DNA or RNA. DNA is a code for life.

Prions are “alive” because they are considered to be a virus and cause disease. They have no DNA, but instead mutated protein.

Viroids are “alive” because thay are capable of causing formation of more viroids, which goes back to the seven characteristics of life, reproduction.