Question

Which statements about viruses are true? select the four statements that are true. select the four statements that are true. all viral genomes contain both dna and rna. hiv contains two identical strands of dna. hiv contains reverse transcriptase. a retrovirus contains rna. the capsid enters the host cell if the virus is enveloped. all rna-containing viruses are retroviruses. enveloped viruses bud from the host cell?

Answer 1

A) All viral genomes contain both DNA and RNA. FALSE. Viruses contain the smallest necessary amount of genetic information packaged in a capsule composed of proteins. Containing both DNA and RNA would be a redundancy that would unnecessarily increase the size of the virus and make it more difficult for the virus to penetrate a cell. B) A retrovirus contains RNA. TRUE. By definition a retrovirus contains single-stranded positive-sense RNA instead of DNA. C) HIV contains two identical strands of DNA. FALSE. HIV is a retrovirus and, therefore, contains RNA instead of DNA. D) HIV contains reverse transcriptase. TRUE. HIV is a retrovirus that contains an RNA genome. All retroviruses require reverse transcriptase to convert their genome from RNA to DNA once the virus has been entered the cell. E) The capsid enters the host cell if the virus is enveloped. TRUE. Viruses are to large to enter a cell by passive diffusion or active transport. The only remaining major form a transport into the cell is endocytosis, or being enveloped. F) All RNA-containing viruses are retroviruses. FALSE. By definition a retrovirus contains single-stranded positive-sense RNA. Viruses can contain RNA in other forms (ie double-stranded) and would, therefore, not be considered a retrovirus. G) Enveloped viruses bud from the host cell. TRUE. Viruses are to large to enter a cell by passive diffusion or active transport. The only remaining major form a transport into the cell is exocytosis. For a virus to exit the host cell and infect other cells, they must exit by exocytosis, or budding.