MCB 2010C - Module 9

A feature that may be found in viruses but never in bacteria is

may contain an RNA genome

The morphological types of viruses are ultimately determined by the

nucleic acid

A clear area against a confluent "lawn" of bacteria is called a

plaque

Which of the following statements is NOT true of lysogeny?

It causes lysis of host cells

Which of the following statements about viral spikes is FALSE?

They are found only on nonenveloped viruses

A viral species is a group of viruses that

has the same genetic information and ecological niche

Which of the following is NOT used as a criterion to classify viruses?

biochemical tests

Which of the following is NOT utilized to culture viruses?

culture media

Bacteriophage replication differs from animal virus replication because only bacteriophage replication involves __________.

injection of naked nucleic acid into the host cell

Assume a patient had chickenpox as a child. Which line on the graph in Figure 13.2 would show the number of viruses present in this person as a 60-year-old with shingles?

e

Assume a patient has influenza. During which time on the graph in Figure 13.2 would the patient show the symptoms of the illness?

c

A persistent (or chronic) infection is one in which __________.

the disease process occurs gradually over a long period

Which of the following would be the first step in biosynthesis of a virus with a - (minus) strand of RNA?

synthesis of double-stranded RNA from an RNA template

An infectious protein is a __________.

prion

An envelope is acquired during which of the following steps?

release

A virus's ability to infect an animal cell depends primarily upon the __________.

presence of receptor sites on the cell membrane

A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?

The virus is causing the death of the infected cells in the patient

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

latent viruses

Oncogenic viruses __________.

cause tumors to develop

What is NOT true regarding viruses that infect plants?

They are often cultured in embryonated chicken eggs

A viroid is a(n) __________.

infectious piece of RNA without a capsid