Some viruses, such as human herpesvirus 1, infect a cell without causing symptoms. These are called:

Viral growth in bird embryos can cause discrete, opaque spots in the embryonic membranes called:

Which acellular infectious agent is described as a tiny, nonliving particle that invades and then reproduces inside a living cell?

Any virus that specifically infects bacteria is called a(n):

Viruses are ___ inside protein shells.

Which group of organisms are viroids (not viruses) most likely to parasitize?

Which of the following is an infectious protein and is simpler than a virus?

Which of the following is a characteristic shared by all viruses?

Enveloped viral membranes are generally derived from host cell membranes with associated virus-specific proteins. Which of the following best completes the statement: 'Enveloped viral membranes are generally ________ with associated virus-specific ________.'?