

MCQOPTIONS
This section includes 30 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.
1. |
Which of the following is true regarding anthrax? |
A. | Anthrax is caused by a virus |
B. | Anthrax is highly contagious |
C. | Inhalation anthrax and cutaneous anthrax are caused by separate strains of |
D. | <i>Bacillus anthracis</i> |
E. | Inhalation Anthrax requires infection with a large number of spores |
Answer» E. Inhalation Anthrax requires infection with a large number of spores | |
2. |
Which of the following characteristic of the Rotavirus was important for the construction of the Rotashield vaccine? |
A. | The possession of a segmented RNA genome |
B. | A limited number of capsule types |
C. | The ability of monkey Rotavirus strains to cause serious illness (diarrhea) in human beings |
D. | The ability of the Rotavirus to be transmitted faster |
Answer» B. A limited number of capsule types | |
3. |
Plastic implants can pose a serious nosocomial infection problem because |
A. | phagocytes have trouble moving on the plastic surface |
B. | phagocytes have trouble engulfing bacteria embedded in a biofilm |
C. | infected implants usually have to be surgically removed |
D. | all of the above |
Answer» E. | |
4. |
The nature of the poliovirus gives for oral vaccination (satin vaccine) as part of the eradication programme is |
A. | heat killed virus |
B. | live attenuated strains of all three immunological types |
C. | small dosage of wild-type live viruses |
D. | formalin-inactivated viruses |
Answer» C. small dosage of wild-type live viruses | |
5. |
Which of the following is common in the disease caused by Coryne-bacterium diphtheriae and Bacillus anthracis? |
A. | Both organisms are gram-positive spore formers |
B. | Diphtheria toxin and edema toxin are ADP ribosylating toxins |
C. | The most serious disease symptoms are the direct result of toxin action |
D. | Both organisms cause skin and respiratory tract infections |
Answer» D. Both organisms cause skin and respiratory tract infections | |
6. |
Fatalities following influenza infection are usually due to the |
A. | dehydration |
B. | bacterial superinfection |
C. | damage to the heart muscle |
D. | formation of granulomas in the lung |
Answer» C. damage to the heart muscle | |
7. |
In the human disease cholera, what is it that actually ends up killing the victim? |
A. | Faulty carrier proteins |
B. | Dehydration and loss of nutrients |
C. | Too little water in the food stream |
D. | the toxin produced by the bacterium |
Answer» C. Too little water in the food stream | |
8. |
Both Mycobacterium tuberculosis and Streptococcus pneumoniae |
A. | are acquired by inhalation |
B. | have cell walls that contain a high content of mycolic acids |
C. | have polysaccharide capsules |
D. | stay in the lung and rarely, if ever, enter the bloodstream |
Answer» B. have cell walls that contain a high content of mycolic acids | |
9. |
Cholera toxin is an A-B type toxin in which the B portions bind to a receptor on a host cell and the A portion enters the cell to cause |
A. | ADP ribosylation of adenylate cyclase that stops production of cAMP |
B. | ADP ribosylation of a G protein that locks it into an active form that stimulates adenylate cyclase to make cAMP |
C. | cleavage of rRNA that results in disruption of ribosome function |
D. | ADP ribosylation of guanylate cyclase that stimulates production of cGMP |
Answer» C. cleavage of rRNA that results in disruption of ribosome function | |
10. |
Mucus helps in protecting against pathogens by |
A. | lowering the pH |
B. | facilitating the growth of normal flora |
C. | blocking access and attachment of pathogens to mucosal surfaces |
D. | sequestering Iron |
Answer» D. sequestering Iron | |
11. |
The toxins produced by bacteria |
A. | kill viruses |
B. | encourage bacterial reproduction |
C. | interfere with physiological processes in the body |
D. | all of the above |
Answer» D. all of the above | |
12. |
Pseudomembraneous colitis is |
A. | precipitated by the use of certain antibiotics |
B. | caused by a gram-positive bacterium |
C. | caused by a spore-forming bacterium |
D. | all of the above |
Answer» E. | |
13. |
Type III secretion systems are used to inject "effector" proteins directly into a host cell. Salmonella uses a type III secretion system to help the pathogen to |
A. | survive the acid pH of the stomach |
B. | secrete LT (heat labile toxin) and ST (heat stable toxin) into the lumen of the intestine |
C. | survive within macrophages |
D. | activate T cells to proliferate and secrete cytokines |
Answer» D. activate T cells to proliferate and secrete cytokines | |
14. |
Which of these cytokines is also known under the name cachectin? |
A. | Interferon gamma |
B. | Interleukin 2 |
C. | Tumor necrosis factor (TNF) |
D. | None of the above |
Answer» D. None of the above | |
15. |
The "A" subunit of diphtheria toxin |
A. | binds host cell receptors found on heart cells |
B. | cause ADP ribosylation of a factor involved in protein synthesis |
C. | forms cAMP that leads to fluid accumulation |
D. | lysis macrophages with the release of cytokines |
Answer» C. forms cAMP that leads to fluid accumulation | |
16. |
What is common in catheters and ventilators? |
A. | They bypass important defenses of the body |
B. | Bacteria responsible for associated infections are usually susceptible to antibiotics |
C. | They predispose patients to viral rather than bacterial infections |
D. | They are used primarily in neonatal intensive care units |
Answer» B. Bacteria responsible for associated infections are usually susceptible to antibiotics | |
17. |
An important host defense of human beings is a dense resident microbiota associated with |
A. | lungs |
B. | bladder |
C. | uterus |
D. | vagina |
Answer» E. | |
18. |
The influenza vaccine is administered each year because |
A. | mutations in the viral hemagglutinin may allow the virus to evade the immune response elicited by previous vaccines |
B. | it is a polysaccharide vaccine that does not confer long-term protection |
C. | the vaccine is sufficiently toxic to make it necessary to administer only a small amount at any one time |
D. | none of the above |
Answer» B. it is a polysaccharide vaccine that does not confer long-term protection | |
19. |
Which of the following disease is caused by DNA viruses? |
A. | Poliomyelitis |
B. | Yellow fever |
C. | Measles |
D. | Small pox |
Answer» E. | |
20. |
Prontosil is |
A. | an effective antibacterial when used in animals |
B. | an effective antibacterial when used in in-vitro cultures |
C. | an effective antibacterial both in animals as well as in in-vitro cultures |
D. | not used as an antibacterial agent |
Answer» D. not used as an antibacterial agent | |
21. |
All infections do not cause fever and all fevers are not due to infections which of the following is an example of non-infections cause of fever? |
A. | Typhoid |
B. | Chicken pox |
C. | Rheumatic disease |
D. | Malaria |
Answer» D. Malaria | |
22. |
Each of the 3 virulence factors of Bacillus anthracis i.e. the capsule, edema toxin and lethal toxin can affect the activity of |
A. | B cells |
B. | macrophages |
C. | ciliated epithelial cells |
D. | M cells |
Answer» C. ciliated epithelial cells | |
23. |
Immunization with which of the following toxoid induces high titer serum antibody, but does not protect from the corresponding disease? |
A. | Tetanus |
B. | Botulism |
C. | Diphtheria |
D. | Shigellosis |
Answer» C. Diphtheria | |
24. |
Which of the following statements is not true regarding Mycobacterium tuberculosis and/or the disease it causes? |
A. | The pathogen contains mycolic acid in its cell wall |
B. | The pathogen can live inside macrophages |
C. | Antibodies to the pathogen are protective |
D. | None of these |
Answer» D. None of these | |
25. |
Coxsackie virus B3, a subgroup of enteroviruses, commonly causes |
A. | acute hemorrhagic conjunctivitis |
B. | muscular dystrophy |
C. | myocarditis |
D. | gastroenteritis |
Answer» D. gastroenteritis | |
26. |
Lactoferrin helps to protect against pathogens by |
A. | sequestering Iron |
B. | blocking sebum production |
C. | lowering the pH |
D. | facilitating the growth of normal flora |
Answer» B. blocking sebum production | |
27. |
Which of the following disease is not caused by microbial protein toxin? |
A. | Botulism |
B. | Diphtheria |
C. | Shigella dysentery |
D. | Tuberculosis |
Answer» E. | |
28. |
The agent responsible for causing mad cow disease is thought to be a |
A. | fungus |
B. | protozoan |
C. | prion |
D. | virus |
Answer» D. virus | |
29. |
A major difference between EHEC and EPEC is |
A. | EHEC secretes a Shiga-like toxin and EPEC does not |
B. | EHEC possesses a type III secretion system and EPEC does not |
C. | EPEC rearranges host cell actin and EHEC does not |
D. | EPEC passes through the placenta to infect the fetus and EHEC does not |
Answer» B. EHEC possesses a type III secretion system and EPEC does not | |
30. |
Which is not a major defense mechanism in the stomach? |
A. | Proteolytic enzymes |
B. | Low pH |
C. | Dense normal flora |
D. | All of these |
Answer» D. All of these | |