Question 1
Antibiotic treatment is very effective in clearing Bordetella pertussis and the disease caused by it.
A. True
B. False
View Answer
Answer: Option B
Explanation:
The above statement is false. Antibiotic treatment is very effective in clearing Bordetella pertussis but has little consequences on the disease, mostly because the disease can only be diagnosed when the bacteria has already released the toxins that are responsible for local and systemic damages.
Question 2
Dengue virus belongs to which of the following category?
A. Lentivirus
B. Coronavirus
C. Filovirus
D. Flavivirus
View Answer
Answer: Option D
Explanation:
Dengue virus belongs to the flavivirus category. Dengue is caused by DENV. DENV consists of four serotypes (DEN1-4), which vary from one another at the amino acid level by 25-40 %. Dengue virus does not belong tothe lentivirus, coronavirus, or filovirus category.
Question 3
In chemically detoxified vaccines the structural epitopes of the pathogen should be destroyed.
A. True
B. False
View Answer
Answer: Option B
Explanation:
The above statement is false. In chemically detoxified vaccines the structural epitopes of the pathogen should not be destroyed. It is necessary to identify conditions which on the one hand fully inactivate and/or microorganisms which would otherwise be dangerous, and on the other hand, do not destroy the structural epitopes relevant for inducing protective immunity.
Question 4
Infection of HIV-1 is initiated by the binding of gp120 to CD4 and a co-receptor on host cells, triggering large scale conformational changes in gp41 that eventually lead to membrane fusion.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. Infection of HIV-1 is initiated by the binding of gp120 to CD4 and a co-receptor on host cells, triggering large scale conformational changes in gp41 that eventually lead to membrane fusion. Therefore, the gp120 protein is of immense importance to HIV-1.
Question 5
Influenza is a DNA virus that causes respiratory tract infections in mammals and some bird species.
A. True
B. False
View Answer
Answer: Option B
Explanation:
The above statement is false. Influenza is an RNA virus that causes respiratory tract infections in mammals and some bird species. It is an enveloped virus containing two coat proteins: hemagglutinin (HA), which is responsible for host cell receptor binding and membrane fusion, and neuraminidase (NA), which cleaves sialic acid residues to release newly budding viral particles from the host cell.
Question 6
Most viral vaccines are thought to work by which of the following technique?
A. Inducing the production of antigens
B. Inducing the production of cell wall
C. Inducing the production of cytosolic proteins
D. Inducing the production of antibodies
View Answer
Answer: Option D
Explanation:
Most viral vaccines are thought to work by inducing the production of antibodies, that block infection or reduce viral load, thereby providing host protection or blunting infection such that cellular immunity can be effective. Inducing the production of antigens, inducing the production of a cell wall, and inducing the production of cytosolic proteins are not the techniques by which most of the viral vaccines work.
Question 7
Protein-based subunit vaccines initiate T cell-dependent activation of B cells.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. Protein-based subunit vaccines initiate T cell-dependent activation of B cells, a process characterized by a more robust immune response, affinity maturation, and immunological memory. On the contrary, polysaccharide vaccines are unable to recruit the assistance of T helper cells and thus rely on T cell-dependent activation alone.
Question 8
The chemical reaction in chemical detoxification should be reversible.
A. True
B. False
View Answer
Answer: Option B
Explanation:
The above statement is false. The chemical reaction in chemical detoxification should be irreversible. If the chemical reaction is reversible the toxicity may be restored by the long-term storage. Moreover, the production process requires handling large quantities of very dangerous materials.
Question 9
The chemically detoxified vaccines are very efficacious and inexpensive.
A. False
B. True
View Answer
Answer: Option B
Explanation:
The above statement is true. The chemically detoxified vaccines are very efficacious and inexpensive. Widely used vaccines based on chemical detoxification are diphtheria, tetanus, whole-cell pertussis, polio, influenza, and many others.
Question 10
The first recombinant vaccine produced targeted the surface antigen of which of the following virus?
A. DENV1
B. Ebola virus
C. Hepatitis A virus
D. Hepatitis B virus
View Answer
Answer: Option D
Explanation:
Recombinant vaccines, as their name suggests, are protein-based vaccines (PBV) that are produced using recombinant DNA technology. The first recombinant PBV was produced in yeast in 1986 and targeted the surface antigen of the hepatitis B virus.
Question 11
Which of the following is not the way in which antibodies participate in host defense?
A. Opsonization
B. Enhance uptake by phagocytic cells
C. Activation of complement proteins
D. Directly destroy the antigen
View Answer
Answer: Option D
Explanation:
Antibodies can participate in host antigen defense in several ways, including opsonization, the coating of viruses to enhance uptake by phagocytic cells, or activation of complement proteins that can directly destroy the pathogens or enhance phagocytic uptake. Whereas, antibodies do not directly destroy the antigen it binds.
Question 12
Which of the following is the only way to control pertussis?
A. Antibiotic treatment
B. Heavy medications
C. Accurate diagnosis
D. Vaccination
View Answer
Answer: Option B
Explanation:
Vaccination is the only way to control pertussis. However, despite its efficacy, the inactivated, whole-cell vaccine is not widely used mostly because of the side effects associated with it. Whereas antibiotic treatment, heavy medications, and accurate diagnosis cannot control pertussis.
Question 13
Which of the following is the pathogen of Pertussis?
A. Staphylococcus aureus
B. Salmonella typhi
C. Clostridium botulinum
D. Bordetella pertussis
View Answer
Answer: Option D
Explanation:
Bordetella pertussis is the pathogen of Pertussis. It is a gram-negative bacterium that adheres to the cilia of the upper respiratory tract of humans and induces local systemic damages by releasing several toxic substances, including pertussis toxin. Staphylococcus aureus, Salmonella typhi, or Clostridium botulinum are not pathogens of pertussis.
Question 14
Which of the following toxin does not have ADP-ribosylation activity?
A. Pertussis toxin
B. E. coli heat-labile toxin
C. Cholera toxin
D. Botulinum toxin A
View Answer
Answer: Option D
Explanation:
Botulinum toxin A does not have ADP-ribosylation activity. Pertussis toxin, Cholera toxin, and E. coli heat-labile toxins have ADP-ribosylation activity. In the ADP-ribosylation reaction, the toxins bind NAD and transfer the ADP-ribose moiety to the major target protein.