Question 1

A new infectious agent has been isolated from deer ticks. It lacks a cell wall but has 70S ribosomes. This agent is most likely a

Accepted Answer

A)  Bacterium 
B) Chlamydia species 
C) Mycoplasma species 
D) Rickettsia species 
E) Virus C

Question 2

Quaternary ammonium compounds inactivate bacteria because they

Accepted Answer

A)  Alter metabolic properties of membranes 
B) Bind irreversibly to DNA 
C) Denature proteins 
D) Inactivate 50S ribosomes 
E) Oxidize free sulfhydryl groups A

Question 3

The infectious agent associated with Creutzfeldt-Jakob disease is extremely hardy, but can be inactivated by

Accepted Answer

A)  Catalases 
B) Hyaluronidases 
C) Nucleases 
D) Phospholipases 
E) Proteases E

Question 4

The minimal concentration of alcohol necessary to kill bacteria and enveloped viruses is

Accepted Answer

A)  30% 
B) 40% 
C) 50% 
D) 60% 
E) 70%

Question 5

A pharmaceutical company has developed a new compound that is well tolerated by the body and inhibits the sterol ergosterol synthesis. Screening of anti-infectious agent activity should be directed toward

Accepted Answer

A)  Bacteria 
B) Chlamydia species 
C) Fungi 
D) Rickettsia species 
E) Viruses

Question 6

Dimorphism is a characteristic of

Accepted Answer

A)  Bacteria 
B) Fungi 
C) Prions 
D) Rickettsia species 
E) Viruses

Question 7

The normal flora of the large intestine consists mainly of

Accepted Answer

A)  Bacteria 
B) Fungi 
C) Protozoa 
D) Viruses 
E) No microbial agents

Question 8

50S ribosomal subunits are found in

Accepted Answer

A)  Bacteria 
B) Fungi 
C) Prions 
D) Protozoa 
E) Viruses

Question 9

Human obligate intracellular pathogens that depend on the host cell for ATP production are

Accepted Answer

A)  Bacteriophages 
B) Mycoplasma species 
C) Prions 
D) Rickettsia species 
E) Viroids

Exam 1: General Properties of Microorganisms