Micro Unit 4

Which term refers to the destruction of many or most pathogenic microorganisms on inanimate objects, but does not necessarily destroy bacterial spores?

A. Sterilization
B. Disinfection
C. Antisepsis
D. Degermation

b

Which term refers to the use of chemicals on living tissue, such as skin, to reduce or destroy microorganisms?

A. Antisepsis
B. Sterilization
C. Disinfection
D. Pasteurization

a

Which term means reducing the number of microorganisms to a level considered safe by public health standards, rather than eliminating all microbes?

A. Sterilization
B. Sanitization
C. Antisepsis
D. Sporulation

b

Which term refers specifically to the destruction of vegetative microorganisms, but not necessarily bacterial endospores?

A. Bactericidal action
B. Bacteriostatic action
C. Sterilization
D. Antisepsis

a

Which term means an agent inhibits bacterial growth and reproduction without necessarily killing the bacteria?

A. Bactericidal
B. Bacteriostatic
C. Sterilizing
D. Sporocidal

b

Which term means an agent is capable of killing bacterial endospores?

A. Bacteriostatic
B. Sporocidal
C. Antiseptic
D. Sanitizing

b

What is the main principle behind a steam autoclave?

A. Dry heat destroys microbes by oxidation
B. Pressurized steam raises the temperature above boiling and denatures microbial proteins
C. Radiation damages microbial DNA
D. Chemicals dissolve bacterial cell walls

b

A common autoclave cycle for sterilization is approximately:

A. 60°C for 5 minutes
B. 100°C for 1 minute
C. 121°C at about 15 psi for around 15 minutes
D. 200°C at atmospheric pressure for 30 seconds

c

Which factor is most important for effective autoclave sterilization besides reaching the correct temperature and pressure?

A. Proper steam contact with all surfaces
B. Keeping items completely dry
C. Using only glass materials
D. Adding disinfectant to the chamber

a

Which type of indicator is considered the best evidence that an autoclave cycle actually achieved sterilization conditions capable of killing resistant organisms?

A. Autoclave tape
B. Pressure gauge
C. Biological indicator containing bacterial spores
D. Thermometer only

c

Which organism is commonly used in a biological indicator for steam autoclave monitoring?

A. Escherichia coli
B. Geobacillus stearothermophilus
C. Staphylococcus aureus
D. Pseudomonas aeruginosa

b

Which method uses dry heat to sterilize materials and primarily kills microorganisms through oxidation and protein damage?

A. Autoclaving
B. Hot-air oven
C. Filtration
D. Ultraviolet light

b

Which physical method is best for sterilizing a heat-sensitive liquid?

A. Autoclaving
B. Dry heat
C. Filtration
D. Boiling

c

Which physical agent primarily kills microorganisms by causing DNA damage such as thymine dimers, and is commonly used for surface or air disinfection rather than deep sterilization?

A. Ultraviolet light
B. Autoclave steam
C. Dry heat
D. Filtration

a

Which form of radiation has greater penetrating power and can be used to sterilize disposable medical supplies?

A. Ultraviolet radiation
B. Ionizing radiation
C. Visible light
D. Infrared radiation

b

Which chemical agent works mainly by denaturing proteins and disrupting cell membranes and is commonly used as an antiseptic or disinfectant?

A. Alcohol
B. Agar
C. Peptone
D. Saline

a

Which chemical agent is especially useful for high-level disinfection or sterilization of heat-sensitive medical equipment?

A. Ethylene oxide
B. Saline
C. Agar
D. Distilled water

a

Which environmental condition can reduce the effectiveness of a disinfectant by protecting microorganisms from direct contact?

A. Presence of blood, pus, or other organic material
B. Proper cleaning before disinfection
C. Correct disinfectant concentration
D. Adequate contact time

a

Which of the following is the best biological monitor for a steam autoclave?

A. Autoclave tape that changes color
B. A thermometer reading 121°C
C. A spore test containing Geobacillus stearothermophilus
D. A pressure gauge reading 15 psi

c

Which statement about autoclave tape is correct?

A. It proves that all spores were killed
B. It is a biological indicator
C. It shows that the item was exposed to autoclave conditions, but does not prove sterility
D. It measures microbial growth directly

c (chemical indicator)

Why is air removal important in a steam autoclave?

A. Air pockets can prevent steam from reaching the load and reduce sterilization effectiveness
B. Air increases the temperature too much
C. Air kills spores faster than steam
D. Air prevents the pressure gauge from working

a

Which statement best explains why moist heat is generally more effective than dry heat at the same temperature?

A. Moist heat penetrates better and denatures proteins more efficiently

B. Dry heat cannot kill bacteria

C. Moist heat only works on viruses

D. Dry heat lowers osmotic pressure

a