Vaccination aims to stimulate an adaptive immune response by exposing the immune system to a harmless form of the pathogen, leading to the development of memory.
Correct Answer: C — To stimulate an adaptive immune response
Q. What is the primary role of phagocytes in the immune response?
A.To produce antibodies
B.To present antigens to T cells
C.To engulf and destroy pathogens
D.To release histamines
Solution
Phagocytes, such as macrophages and neutrophils, primarily function to engulf and destroy pathogens through phagocytosis.
Correct Answer: C — To engulf and destroy pathogens
Q. What is the primary role of T helper cells in the immune response?
A.Directly kill infected cells
B.Produce antibodies
C.Activate B cells and cytotoxic T cells
D.Phagocytose pathogens
Solution
T helper cells play a crucial role in the immune response by activating B cells to produce antibodies and cytotoxic T cells to kill infected cells.
Correct Answer: C — Activate B cells and cytotoxic T cells
Q. What is the primary target of the hepatitis B vaccine?
A.Hepatitis A virus
B.Hepatitis B virus
C.Hepatitis C virus
D.HIV
Solution
The hepatitis B vaccine is designed to protect against the hepatitis B virus, which can cause serious liver disease.
Correct Answer: B — Hepatitis B virus
Q. What is the primary vector for the transmission of malaria?
A.Aedes mosquito
B.Culex mosquito
C.Anopheles mosquito
D.Tsetse fly
Solution
The Anopheles mosquito is the primary vector responsible for transmitting the malaria parasite to humans.
Correct Answer: C — Anopheles mosquito
Q. What is the recommended contact time for a 10% bleach solution to effectively disinfect surfaces?
A.1 minute
B.5 minutes
C.10 minutes
D.15 minutes
Solution
A 10% bleach solution is recommended to be in contact with surfaces for at least 5 minutes for effective disinfection.
Correct Answer: B — 5 minutes
Q. What is the role of a biological indicator in sterilization processes?
A.To measure temperature
B.To confirm the presence of microorganisms
C.To verify the effectiveness of sterilization
D.To disinfect surfaces
Solution
Biological indicators are used to verify the effectiveness of sterilization by demonstrating that spores have been killed.
Correct Answer: C — To verify the effectiveness of sterilization
Q. What is the role of a biological indicator in sterilization?
A.To measure temperature
B.To confirm the presence of microorganisms
C.To verify the effectiveness of the sterilization process
D.To indicate the type of sterilization method used
Solution
Biological indicators are used to verify the effectiveness of the sterilization process by confirming the destruction of specific microorganisms.
Correct Answer: C — To verify the effectiveness of the sterilization process
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. What is the role of antibodies in the immune response?
A.Directly kill pathogens
B.Neutralize toxins and pathogens
C.Activate complement system
D.All of the above
Solution
Antibodies play multiple roles in the immune response, including neutralizing toxins and pathogens, opsonizing for phagocytosis, and activating the complement system.
Correct Answer: D — All of the above
Q. What is the role of antibodies in the immune system?
A.To directly kill pathogens
B.To neutralize toxins
C.To enhance phagocytosis
D.All of the above
Solution
Antibodies play multiple roles in the immune response, including neutralizing toxins, enhancing phagocytosis, and directly targeting pathogens.
Correct Answer: D — All of the above
Q. What is the role of antigen-presenting cells (APCs) in the immune response?
A.To produce antibodies
B.To present antigens to T cells
C.To directly kill pathogens
D.To secrete cytokines
Solution
Antigen-presenting cells (APCs) process and present antigens to T cells, initiating the adaptive immune response.
Correct Answer: B — To present antigens to T cells
Q. What is the role of autoclaving in sterilization?
A.It uses chemical agents to kill microorganisms.
B.It uses high pressure and steam to achieve sterilization.
C.It relies on ultraviolet light to disinfect surfaces.
D.It is a method of physical disinfection only.
Solution
Autoclaving uses high pressure and steam to achieve sterilization, effectively killing all microorganisms, including spores.
Correct Answer: B — It uses high pressure and steam to achieve sterilization.
Q. What is the role of cytokines in the immune response?
A.To directly kill pathogens
B.To signal and regulate immune cell activity
C.To form antibodies
D.To enhance phagocytosis
Solution
Cytokines are signaling molecules that regulate and coordinate the immune response by influencing the activity of immune cells.
Correct Answer: B — To signal and regulate immune cell activity
Q. What is the role of dendritic cells in the immune response?
A.To produce antibodies
B.To present antigens to T cells
C.To kill infected cells
D.To secrete cytokines
Solution
Dendritic cells are professional antigen-presenting cells that capture and present antigens to T cells, initiating the adaptive immune response.
Correct Answer: B — To present antigens to T cells
Q. What is the role of dendritic cells in the immune system?
A.Produce antibodies
B.Present antigens to T cells
C.Kill pathogens directly
D.Secrete cytokines
Solution
Dendritic cells are professional antigen-presenting cells that capture, process, and present antigens to T cells, initiating the adaptive immune response.
Correct Answer: B — Present antigens to T cells
Q. What is the role of helper T cells in the immune response?
A.Directly kill infected cells
B.Stimulate B cells and cytotoxic T cells
C.Produce antibodies
D.Engulf pathogens
Solution
Helper T cells play a crucial role in stimulating B cells to produce antibodies and activating cytotoxic T cells.
Correct Answer: B — Stimulate B cells and cytotoxic T cells
Q. What is the role of surfactants in disinfection?
A.Increase the pH of the solution
B.Enhance the penetration of disinfectants
C.Neutralize microbial toxins
D.Stabilize the disinfectant solution
Solution
Surfactants enhance the penetration of disinfectants by reducing surface tension, allowing better contact with microbes.
Correct Answer: B — Enhance the penetration of disinfectants
Q. What is the role of T helper cells in the immune response?
A.To kill infected cells
B.To produce antibodies
C.To activate B cells and cytotoxic T cells
D.To phagocytize pathogens
Solution
T helper cells are crucial for activating B cells and cytotoxic T cells, coordinating the adaptive immune response.
Correct Answer: C — To activate B cells and cytotoxic T cells
Q. What is the role of the microbiome in human health?
A.It causes diseases.
B.It has no significant role.
C.It aids in digestion and immune function.
D.It only affects skin health.
Solution
The microbiome plays a crucial role in digestion, nutrient absorption, and modulating the immune system.
Correct Answer: C — It aids in digestion and immune function.
Q. What is the typical antibody concentration in serum after a secondary immune response compared to a primary response?
A.Lower
B.Similar
C.Higher
D.No antibodies produced
Solution
The antibody concentration in serum after a secondary immune response is typically much higher than that of a primary response.
Correct Answer: C — Higher
Q. What laboratory technique is commonly used to identify bacterial species based on their cell wall characteristics?
A.PCR
B.Gram staining
C.ELISA
D.Western blotting
Solution
Gram staining is a differential staining technique that classifies bacteria into Gram-positive and Gram-negative based on their cell wall structure.
Correct Answer: B — Gram staining
Q. What laboratory test is commonly used to diagnose streptococcal pharyngitis?
A.Blood culture
B.Rapid antigen test
C.PCR test
D.Urinalysis
Solution
A rapid antigen test is commonly used to quickly diagnose streptococcal pharyngitis by detecting Group A Streptococcus.
Correct Answer: B — Rapid antigen test
Q. What role do T helper cells play in the immune response?
A.Directly kill infected cells
B.Help activate B cells and cytotoxic T cells
C.Produce antibodies
D.Engulf and digest pathogens
Solution
T helper cells assist in activating B cells and cytotoxic T cells, playing a central role in coordinating the immune response.
Correct Answer: B — Help activate B cells and cytotoxic T cells
Q. What type of cells are primarily involved in the cell-mediated immune response?
A.B cells
B.Cytotoxic T cells
C.Antigen-presenting cells
D.Plasma cells
Solution
Cytotoxic T cells are the main effector cells in the cell-mediated immune response, responsible for killing infected cells.
Correct Answer: B — Cytotoxic T cells
Q. What type of immune response is primarily involved in fighting viral infections?
A.Humoral response
B.Cell-mediated response
C.Innate response
D.Inflammatory response
Solution
The cell-mediated immune response, particularly involving cytotoxic T cells, is primarily responsible for combating viral infections.
Correct Answer: B — Cell-mediated response
Q. What type of immunity is conferred by maternal antibodies transferred to a newborn?
A.Active immunity
B.Passive immunity
C.Innate immunity
D.Cell-mediated immunity
Solution
Passive immunity is conferred by the transfer of maternal antibodies to the newborn, providing temporary protection against infections.
Correct Answer: B — Passive immunity
Q. What type of immunity is provided by vaccination?
A.Innate immunity
B.Passive immunity
C.Active immunity
D.Cell-mediated immunity
Solution
Vaccination stimulates the immune system to produce an immune response, leading to active immunity against specific pathogens.
Correct Answer: C — Active immunity
Q. What type of pathogen is Candida albicans?
A.Bacterium
B.Virus
C.Fungus
D.Protozoan
Solution
Candida albicans is a fungus that can cause opportunistic infections, particularly in immunocompromised individuals.
Correct Answer: C — Fungus
Q. What type of vaccine is the MMR vaccine?
A.Inactivated
B.Live attenuated
C.Subunit
D.Toxoid
Solution
The MMR vaccine is a live attenuated vaccine that protects against measles, mumps, and rubella.