a) Microorganisms that require low pH for growth.
b) Microorganisms that can’t perform osmosis.
c) Microorganisms that require the presence of a low solute concentration.
d) Microorganisms that are able to grow in the presence of a high solute concentration.
2) What is the mechanism behind the action of UV light on microorganisms?
a) It promotes chemical and physical changes in nucleic acids and proteins.
b) It stops bacterial endospore formation.
C) It causes dehydration of the cell
D) It causes osmotic lysis
3) What is the activity of plain soap to prevent transmission of infectious disease?
A) Soap is positively charged and acts to disrupt membranes of bacteria.
B) Soap creates reactive oxygen species to disrupt cellular functions
C) Soap binds to nucleic acids to create thymine dimers
D) Soap acts as a degerming agent to remove oil and surface microbes
4) Often the number of bacteria isolated off of hands after hand washing actually INCREASES with more washes. Why?
A) Because washing stimulates rapid bacterial growth.
B) Because hand washing doesn’t work to remove bacteria.
C) Because the soap or hand sanitizer is contaminated.
D) Because you begin to remove resident flora after several washes
5) Which organism is the most resistant to the lethal effects of ultraviolet light?
A) A protozoan that does not form cysts
B) A spore-forming bacteria
C) A virus
D) A gram negative bacteria
6) Since 70% alcohol acts to denature proteins, but this action takes time. What are we really accomplishing by swabbing a patient prior to hypodermic needle injection?
A) Killing of all surface bacteria
B) Cleaning the area and removal of some surface bacteria.
C) Contamination of the injection site with pathogens
D) Complete sterilization of the injection site