CH. 24 STUDY GUIDE

What are the viruses that attack bacteria?

phages

The five stages of a lytic infection are attachment, penetration, __________, assembly, and release.

replication

The specificity of viruses to different types of cells is due to ____ sites on the host cell.

receptor

What is the purpose of phage therapy?

To target specific bacteria in the body and destroy them

Refer to the accompanying figure. What is the function of the structure labeled as 3? {GRAPH}

locomotion

Viral infections in humans spread via the circulatory system. Viral infections in plants spread from cell to cell via:

plasmodesmata.

Which characteristic defines a virus?

Viruses cannot metabolize.

Which structure of the virus in the accompanying figure is the capsid? {GRAPH}

2

Which statement about viruses is FALSE? a. Viruses are not cellular. b. Viruses can manufacture proteins. c. Viruses cannot carry on metabolic activities. d. Viruses can only replicate by infecting other cells. e. Viruses have a protective protein coat called a capsid.

b. Viruses can manufacture proteins.

Which statement describes a temperate virus? a. A temperate virus undergoes a lytic cycle. b. A temperate virus is considered virulent. c. A temperate virus does not always destroy its host. d. A temperate virus does not undergo a lysogenic cycle. e. A temperate virus always destroys their host immediately.

c. A temperate virus does not always destroy its host.

What is the protein coat of a virus called?

capsid

What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?

lysogenic

Which statement describes a virulent phage? a. A virulent phage infects viruses. b. A virulent phage infects prions. c. A virulent phage infects virions. d. A virulent phage destroys bacteria. e. A virulent phage infects but does not destroy bacteria.

d. A virulent phage destroys bacteria.

How are viruses classified?

By their host range and other characteristics

Before an animal cell's membrane fuses with a virus, the virus must first:

attach to a specific receptor on the plasma membrane of the host cell.