Name: 

Viruses



True/False
Indicate whether the sentence or statement is true or false.
 

1. 

Although viruses do not consist of cells, biologists consider them to be living because they are capable of reproduction.
 

2. 

Wendell Stanley made the important discovery that viruses are not cellular.
 

3. 

Viruses consist of RNA or DNA surrounded by a coat of protein.
 

4. 

Prions are the smallest known particles that are able to replicate.
 

5. 

A virus can only reproduce by controlling a cell.
 

6. 

People can contract the influenza virus more than once because the virus tends to mutate rapidly, avoiding the actions of the immune system.
 

7. 

Smallpox is caused by bacteria.
 

8. 

Chickenpox and shingles are caused by the same virus.
 

9. 

The viruses that have been linked to human cancers are usually transmitted through the air.
 

Completion
Complete each sentence or statement.
 

10. 

The protein coat of a virus is called a(n) ____________________.
 

 

11. 

Most viruses occur in the shape of a(n) ____________________ or a(n) ____________________.
 

 

12. 

A virus that transcribes DNA from an RNA template is called a(n) ____________________.
 

 

13. 

An enzyme called ____________________ manufactures DNA that is complementary to a virus’s RNA.
 

 

14. 

____________________ are bacterial viruses with a polyhedral head and a helical tail.
 

 

15. 

All viruses reproduce by taking over the reproductive machinery of a ____________________.
 

 

16. 

Viruses that infect a host cell and have their nucleic acid replicated but do not harm the host cell are in a ____________________ cycle.
 

 

17. 

A viral DNA molecule formed from an RNA virus is called a(n) ____________________.
 

 

18. 

The virus that causes AIDS is called ____________________.
 

 

19. 

Some viruses are thought to induce ____________________, a disease characterized by uncontrolled cell division.
 

 

20. 

An example of an emerging virus is the  ____________________ virus.
 

 



 
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