Q. What is the minimum effective concentration of alcohol for disinfection?
A.50%
B.70%
C.90%
D.100%
Solution
The minimum effective concentration of alcohol for disinfection is typically around 70%, as it allows for better penetration and efficacy.
Correct Answer: B — 70%
Q. What is the most effective method for sterilizing heat-sensitive medical instruments?
A.Autoclaving
B.Ethylene oxide gas
C.Boiling water
D.Hydrogen peroxide vapor
Solution
Ethylene oxide gas is commonly used for sterilizing heat-sensitive medical instruments as it effectively penetrates materials without damaging them.
Correct Answer: B — Ethylene oxide gas
Q. What is the primary mechanism of action for glutaraldehyde as a disinfectant?
A.Oxidation of cellular components
B.Denaturation of proteins
C.Disruption of nucleic acids
D.Inhibition of cell wall synthesis
Solution
Glutaraldehyde acts primarily by denaturing proteins, which leads to the inactivation of microorganisms.
Correct Answer: B — Denaturation of proteins
Q. What is the primary purpose of sterilization in a clinical setting?
A.To reduce microbial load
B.To eliminate all forms of microbial life
C.To disinfect surfaces
D.To enhance immune response
Solution
Sterilization aims to eliminate all forms of microbial life, including bacteria, viruses, fungi, and spores.
Correct Answer: B — To eliminate all forms of microbial life
Q. What is the role of alcohol in disinfection?
A.To kill spores
B.To denature proteins and disrupt membranes
C.To oxidize cellular components
D.To inhibit nucleic acid synthesis
Solution
Alcohol acts as a disinfectant by denaturing proteins and disrupting cellular membranes, making it effective against many microorganisms.
Correct Answer: B — To denature proteins and disrupt membranes
Q. Which of the following is a common application of disinfection in healthcare?
A.Sterilizing surgical instruments
B.Cleaning surfaces in patient rooms
C.Preparing culture media
D.Vaccination preparation
Solution
Disinfection is commonly applied to clean surfaces in patient rooms to reduce the risk of infection.
Correct Answer: B — Cleaning surfaces in patient rooms
Q. Which of the following is a common application of sterilization in laboratories?
A.Disinfecting countertops
B.Sterilizing culture media
C.Cleaning glassware
D.Preparing vaccines
Solution
Sterilization is commonly applied to culture media in laboratories to ensure that no contaminants are present during microbial growth.
Correct Answer: B — Sterilizing culture media
Q. Which of the following is a limitation of using bleach as a disinfectant?
A.It is ineffective against viruses
B.It can corrode surfaces
C.It is too expensive
D.It requires a long contact time
Solution
Bleach can corrode surfaces, which limits its use in certain environments despite its effectiveness against a wide range of pathogens.
Correct Answer: B — It can corrode surfaces
Q. Which of the following is a method of sterilization that uses high-pressure steam?
A.Dry heat sterilization
B.Chemical vapor sterilization
C.Autoclaving
D.Radiation sterilization
Solution
Autoclaving is a method of sterilization that uses high-pressure steam to kill all forms of microbial life.
Correct Answer: C — Autoclaving
Q. Which of the following methods is NOT typically used for sterilization?
A.Autoclaving
B.Dry heat
C.Chemical disinfection
D.Filtration
Solution
Chemical disinfection is used to reduce microbial load but does not guarantee the elimination of all microorganisms, thus it is not a sterilization method.
