A naked virus __________  .


a. lacks a membranous envelope
b. has injected its DNA or RNA into a host cell
c. is devoid of capsomeres
d. is one that is unattached to a host cell

All of the following can be transmitted by recreational (i.e., swimming) water sources except

a. amebic dysentery.

b. cholera.

c. giardiasis.

d. hepatitis B.

e. salmonellosis.

Which of the following is not an acellular agent?

a. viroid

b. virus

c. rickettsia

d. prion

Which of the following statements is true?

a. Viruses move toward their host cells.

b. Viruses are capable of metabolism.

c. Viruses lack a cytoplasmic membrane.

d. Viruses grow in response to their environmental conditions.

A virus that is specific for a bacterial host is called a __________ .

a. phage

b. prion

c. virion

d. viroid

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 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