1. Introduction to Microbiology

Which of the following statements is false?

a. Viruses may have circular DNA.

b. dsRNA is found in bacteria more often than in viruses.

c. Viral DNA may be linear.

d. Typically, viruses have DNA or RNA but not both.

Another name for a complete virus is ___________ .

a. virion

b. viroid

c. prion

d. capsid

Which of the following viruses can be latent?

a. HIV

b. chicken pox virus

c. herpesviruses

d. all of the above

Which of the following is not a criterion for specific family classification of viruses?

a. the type of nucleic acid

b. envelope structure

c. capsid type present

d. lipid composition

A clear zone of phage infection in a bacterial lawn is __________ .

a. a prophage

b. a plaque

c. naked

d. a zone of inhibition

Match each numbered term with its following description.

1. _________ uncoating

2. _________ prophage

3. _________ retrovirus

4. _________ bacteriophage

5. _________ capsid

6. _________ envelope

7. _________ virion

8. _________ provirus

9. _________ benign tumor

10. ________ cancer

A. dormant virus in a eukaryotic cell

B. a virus that infects a bacterium

C. transcribes DNA from RNA

D. protein coat of virus

E. a membrane on the outside of a virus

F. complete viral particle

G. inactive virus within bacterial cell

H. removal of capsomeres from a virion

I. invasive neoplastic cells

J. harmless neoplastic cells

Label each step in the bacteriophage replication cycle below.

a._______<IMAGE>

b._______<IMAGE>

c._______<IMAGE>

d._______<IMAGE>

Identify the viral capsid shapes.

a. ___________ <IMAGE>

b. ___________ <IMAGE>

c. ___________ <IMAGE>

d. ___________ <IMAGE>

Compare and contrast a bacterium and a virus by writing either “Present” or “Absent” for each of the following structures.

What is the difference between a virion and a virus particle?