Practice Questions

Rabies virus travels through peripheral nerves to the central nervous system, causing fatal encephalitis if untreated.

Most plant viruses enter through wounds or are transmitted by insect vectors such as aphids because intact plant cell walls prevent direct entry.

The contractile tail sheath helps inject viral DNA through the bacterial cell wall into the host cytoplasm.

Lipid envelopes are easily disrupted by detergents, alcohol, and drying, resulting in loss of infectivity.

SARS-CoV-2 is an enveloped positive-sense single-stranded RNA virus belonging to the Coronaviridae family.

Zoonotic viruses naturally circulate among animals but can also infect humans. Rabies virus and some coronaviruses are examples.

Adenovirus lacks a lipid envelope and possesses an icosahedral protein capsid enclosing double-stranded DNA.

RNA polymerases lack efficient proofreading mechanisms, resulting in frequent mutations and rapid viral evolution.

Herpesviruses possess large linear double-stranded DNA genomes enclosed within an icosahedral capsid.

Negative-sense RNA cannot be translated directly. It must first be converted into positive-sense RNA by viral RNA-dependent RNA polymerase.