Explore topic-wise MCQs in Microbiology.

This section includes 285 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 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
2.

Which of the following is common in the disease caused by and ?

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
3.

Each of the 3 virulence factors of 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
4.

Both and

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
5.

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
6.

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.
7.

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
8.

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. Inhalation Anthrax requires infection with a large number of spores
Answer» E.
9.

Which of the following statements is not true regarding 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
10.

Type III secretion systems are used to inject "effector" proteins directly into a host cell. 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
11.

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
12.

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
13.

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
14.

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
15.

Alternative name for ' hepatocellular carcinoma' is

A. Hepatocytes
B. Lymphocytes
C. Hepatoma
D. Leukocytes
Answer» D. Leukocytes
16.

Which of the following disease is an infection of the reticuloendothelial system?

A. Cryptococcosis
B. Moniliasis
C. Histoplasmosis
D. Coccidioidomycosis
Answer» D. Coccidioidomycosis
17.

The organism causing whooping cough can grow on ordinary culture media.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
18.

Puerperal fever is a streptococcal infection of the ______________

A. kidney
B. skin
C. uterus
D. heart
Answer» D. heart
19.

'CMV' is abbreviation of

A. Cytomegalovirus
B. Cauliflower virus
C. Cow virus
D. Influenza virus
Answer» B. Cauliflower virus
20.

In children 'astrovirus' causes

A. Skin infection
B. Watery diarrhoea
C. Vomiting
D. Brain inflammation
Answer» C. Vomiting
21.

Fungus diseases that occur on the nails, skin, hair are referred to as systemic mycoses.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
22.

Which serovar of C. botulinum occurs mainly in the sediments of the Great Lakes?

A. A
B. B
C. E
D. F
Answer» D. F
23.

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
24.

Which drug is used for treatment of brucellosis in humans?

A. Erythromycin
B. Tetracycline
C. Carbenicillin
D. Gentamicin
Answer» C. Carbenicillin
25.

What is the incubation period for kala azar disease?

A. 24 h
B. 1 month
C. 2-4 months
D. 7 days
Answer» D. 7 days
26.

Kaposi's sarcoma is an opportunistic infection in 'AIDS' patient and is its causative agent in

A. Human herpesvirus 8
B. Human papilloma virus
C. Cytomegalovirus
D. JC virus
Answer» B. Human papilloma virus
27.

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
28.

Which among the following species causes tuberculosis?

A. Mycobacterium leprae
B. Mycobacterium kansasii
C. Mycobacterium bovis
D. Mycobacterium ulcerans
Answer» D. Mycobacterium ulcerans
29.

Other than warts, some species of papilloma virus, may cause 'carcinoma' of the

A. Lungs
B. Vigina
C. Cervix
D. Urethra
Answer» D. Urethra
30.

Which drug is used for treatment of anthrax?

A. erythromycin
B. penicillin
C. tetracycline
D. ampicillin
Answer» C. tetracycline
31.

Coxsackie virus B3, a subgroup of enteroviruses, commonly causes

A. acute hemorrhagic conjunctivitis
B. muscular dystrophy
C. myocarditis
D. gastroenteritis
Answer» D. gastroenteritis
32.

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
33.

Korean 'hemorrhagic' fever is caused by the

A. Adenovirus
B. Hantavirus
C. Cache valley virus
D. Chikungunya virus
Answer» C. Cache valley virus
34.

Natural host for 'respiratory syncytial' virus is

A. Pigs
B. Human
C. Goats
D. Rats
Answer» C. Goats
35.

Blastomyces brasiliensis causes which of the following disease?

A. North American blastomycosis
B. South American blastomycosis
C. Histoplasmosis
D. Sporotrichosis
Answer» C. Histoplasmosis
36.

Complement- fixation is done for laboratory diagnosis of which of the following disease?

A. Poliomyelitis
B. Mumps
C. Measles
D. FMD
Answer» E.
37.

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
38.

'Astrovirus' is

A. Nonenveloped RNA virus
B. Enveloped RNA virus
C. DNA virus
D. Prion
Answer» B. Enveloped RNA virus
39.

'Varicella-zoster' virus is transmitted by the

A. Mouth
B. Genital organs
C. Respiratory droplets
D. Aerosol
Answer» D. Aerosol
40.

A disease that is characterized by ataxia, tremors and itching in sheep is known as

A. Visna
B. Scrapie
C. Jackob disease
D. Spongiform
Answer» C. Jackob disease
41.

Way of transmission of 'arbovirus' is

A. Cattles
B. Monkeys
C. Arthropods
D. Pigs
Answer» D. Pigs
42.

Size of 'togaviruses' is

A. 80 nm
B. 70 nm
C. 35 nm
D. 20 nm
Answer» C. 35 nm
43.

Which drug is used for treatment of leishmaniasis?

A. chloroquine phosphate
B. metronidazole
C. suramin
D. sodium stibogluconate
Answer» E.
44.

Which of the following is incorrect with respect to Paramyxoviruses?

A. large (125 to 250 nm)
B. core of single-stranded (—) RNA
C. rna is segmented
D. hemagglutinin and neuroaminidase activities occur together
Answer» D. hemagglutinin and neuroaminidase activities occur together
45.

SV 40 causes diseases in which animal?

A. monkeys
B. rabbits
C. humans
D. cattle
Answer» B. rabbits
46.

Croup in young children is caused by

A. Parainfluenza virus
B. Influenza B virus
C. Influenza A virus
D. Herpesvirus
Answer» B. Influenza B virus
47.

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
48.

Host for 'poliomyelitis' is limited to

A. Reptiles
B. Aves
C. Primates
D. Amphibians
Answer» D. Amphibians
49.

Polyene antibiotics act on the plasma membrane of the fungus.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
50.

Which of the following toxins cause damage to the tissue cells by its phospholipase action?

A. alpha toxin
B. delta toxin
C. protein A
D. coagulase
Answer» C. protein A