BASIC MEDICAL SCIENCES

1) Which of the following are the examples of the human infections caused by Mycoplasma spp? Select from all the options given below
a) Pneumonia
b) Food poisoning
c) Urethritis
d) Skin infections

2) All of the following are the general characteristics of Mycoplasma spp, EXCEPT?
a) It can grow on cell-free media containing lipoprotein and sterol
b) The size of the bacteria can be as small as 150 to 250 nm
c) It can be identified using gram staining technique
d) The bacteria show pleomorphic motility

3) A 14-year-old boy contracts cough and fever at school where one of his friends from the class had the same symptom for a few days. At the hospital, laboratory sputum culture and gram staining method showed negative results and chest radiography results also did not demonstrate the infection area properly, which is the likely pathogen?
a) Mycoplasma hominis
b) Mycoplasma pneumoniae
c) Mycobacterium leprae
d) Ureaplasma urealyticum

4) Which of the following statements is true about Ureaplasma urealyticum?
a) It can be cultivated routine culture medium
b) It is much larger than other Mycoplasma spp and viruses
c) It requires urea for its growth
d) It is susceptible to penicillin and amoxicillin

5) Mycoplasma spp are resistant to Penicillin?
a) True
b) False

6) A blood sample from a 19-year-old sexually active woman with genital infections was taken and cultured for the isolation of the responsible pathogen. Name the least likely pathogen that can be responsible for the infection?
a) Chlamydia trachomatis
b) Mycoplasma pneumoniae
c) Mycoplasma hominis
d) Mycoplasma genitalium

7) Which of the following bacteria appear as “fried egg” types of colonies when cultured on suitable solid media?
a) Mycoplasma pneumoniae
b) Mycoplasma genitalia
c) Mycoplasma hominis
d) Ureaplasma urealyticum

8) The routine laboratory diagnostics method is usually not helpful for the isolation and identification of Mycoplasma pneumoniae. All of the following are the clinical tests for the diagnosis of the infection in humans caused by M.pneumoniae, EXCEPT?
a)ELISA
b) Complement fixation
c) Cold hemagglutinins
d) Electron microscopy

9) Which of the following cause “community-acquired pneumonia”? Select from all the options given below
a)Streptococcus pneumoniae
b)Chlamydia trachomatis
c) Mycoplasma pneumoniae
d) Haemophilus influenzae

10) Which of the following Mollicutes is associated with the infection “salpingitis” and “postpartum fever”?
a) Mycoplasma genitalium
b) Ureaplasma urealyticum
c) Mycoplasma hominis
d) Mycoplasma pneumoniae


11) Which of the following Mycoplasma spp grow rapidly in both broth and agar medium?
a) Ureaplasma urealyticum
b) Mycoplasma genitalium
c) Mycoplasma pneumoniae
d) None of the above

12) Ureaplasma urealyticum is found in sexually active men and women, about what percentage of women have it?
a) 20 to 40%
b) 40 to 80 % >
c) 5 to 20 %
d) 25 to 45%

13) Mycoplasma pneumoniae infections are most prevalent in what age range of people?
a) 15 to 60
b) 5 to 45
c) 5 to 20
d) 10 to 50

14) Which of the following statements is true regarding the pathogenesis of Mycoplasma infections?
a) Enter the host cell by releasing exotoxin
b) Adherence to the host cells is mediated by the bacterial proteins
c) Inhibited by beta-lactam antibiotics
d) All of the above

15) Which of the following is the drug of choice for Ureaplasma urealyticum infections?
a) Penicillin
b) Tetracyclines
c) Cephalosporins
d) Imipenem


Multiple Choice Answers Review
1)- a) Pneumonia, c) Urethritis
2)- c) It can be identified using gram staining technique
3)- b) Mycoplasma pneumoniae
4)- c) It requires urea for its growth
5)- a) True
6)- b) Mycoplasma pneumoniae
7)- c) Mycoplasma hominis
8)- d) Electron microscopy
9)- a) Streptococcus pneumoniae, c) Mycoplasma pneumoniae, d) Haemophilus influenzae
10)- c) Mycoplasma hominis
11)- a) Ureaplasma urealyticum
12)- b) 40 to 80 %
13)- c) 5 to 20
14)- b) Adherence to the host cells is mediated by the bacterial proteins
15)- b) Tetracyclines

Multiple Choice Question on Cytokines, Interferon & Interleukins

4) Tumor necrosis factor (TNF) is an endogenous pyrogen that induces fever. Which of the following statement is true regarding TNF except:
a) TNF induces IL-1 production for induction of fever
b) TNF induces the synthesis of prostaglandins
c) TNF induces production acute phase proteins
d) TNF level is lower in septic shock

5) Interleukin-1 is an inflammatory cytokine that has the following function except:
a) Inflammation
b) Leukocyte adhesion
c) Production of acute phase reactant protein
d) All of the above

6) Chemokines are the structurally homologous cytokines family that regulate lymphocyte migration. Which of the following is an incorrect statement regarding the cytokines?
a) Chemokines consist of characteristic N-terminal cysteine residues
b) Chemokines are produced by endothelial cells, epithelial cells, and fibroblasts
c) Chemokines are suppressed by microbes, TNF and IL-1
d) Chemokines bind to the heparan sulfate on the endothelial tissue that enables recruitment and trapping of cells into infection sites

7) Interleukin 12 is a key inducer of the cell-mediated immunity in response to infection by intracellular pathogens. Interleukin activate cell-mediated immune response by increasing synthesis of the following cytokines
a) TNF
b) Interferon beta
c) Interferon-gamma
d) Interleukin 1

8) Interferon type I mediate the early innate immune response to viral. Which of the following viral antigens activates production of Type I interferon?
a) Capsid protein
b) Double-stranded RNA
c) Double-stranded DNA
d) None of the above


9) Which of the following cytokine antagonizes the function of IL-12 and absence of specific cytokine in mice develop inflammatory bowel disease?
a) IL-1
b) IL-2
c) IL-10
d) IFN-gamma

10) Which of the following cytokine is used for the treatment of chronic granulomatous disease?
a) INF-alpha
b) INF-beta
c) INF-gamma
d) TNF

11) Which of the following cytokine is used for the treatment of viral hepatitis and multiple sclerosis?
a) INF-alpha
b) INF-beta
c) INF-gamma
d) TNF

12) Which of the following interleukin is responsible for T cell expansion after antigen recognition?
a) IL-1
b) IL-2
c) IL-4
d) IL-5

13) Which of the following interleukin stimulate differentiation of Th2 subset and production of IgE?
a) IL-1
b) IL-2
c) IL-4
d) IL-5

14) Which of the following interleukin activates eosinophil that consists of FcR for IgE?
a) a) IL-1
b) IL-2
c) IL-4
d) IL-5

15) Which of the following cytokines stimulate the production of IgA that is required for mucosal immunity?
a) Interferon-gamma
b) Tumor Necrosis Factor
c) Transforming growth factor-beta
d) All of the above

16) Cytokines recognize and engage with their receptors for biological action. Which of the following is the correct sequence of high-affinity to low-affinity interactions?
a) Antibody> MHC > Cytokine
b) MHC> Antibody > Cytokine
c) Cytokine > Antibody > MHC
d) None of the above

Multiple Choice Question Answers
1)- d) Cell-autonomous
2)- d) All of the above
3)- a) Chemokines receptor
4)- d) TNF level is lower in septic shock
5)- d) All of the above
6)- c) Chemokines are suppressed by microbes, TNF and IL-1
7)- c) Interferon-gamma
8)- b) Double-stranded RNA
9)- c) IL-10
10)- c) INF-gamma
11)- b) INF- beta
12)- b) IL-2
13)- c) IL-4
14)- d) IL-5
15)- c) Transforming growth factor-beta
16)- c) Cytokine > Antibody > MHC

1) What are the different types of Rickettsial infections? Select all the correct answers from all the options given below
a) Epidemic typhus
b) Scrub typhus group
c) Yellow fever
d) Rocky mountain spotted fever

2) All the statements given below are correct about epidemic typhus, Except?
a) It is transmitted by louse to humans
b) People above 40 years of age are most affected
c) Fever lasts for about two weeks
d) It is caused by the pathogen Rickettsia typhi

3) Which of the following Rickettsia spp causes Rickettsialpox in humans transferred from the bites of mites developing a mild fever and rashes resembling caused by varicella?
a) Rickettsia rickettsi
b) Rickettsia akari
c) Rickettsia prowazekii
d) Rickettsia australis

4) Which of the following statements is NOT correct about the characteristics of Rocky Mountain spotted fever?
a) It is caused by Rickettsia rickettsii
b) It is mostly found in the eastern and southeastern region of United States
c) Fever and Skin rashes develop within 6 hours of the ticks' bite
d) Ticks are the primary vectors

5) All of the statements given below are correct about the Ehrlichiosis infections in human, EXCEPT?
a) Ehrlichia chaffeensis is the causative organism
b) Ticks are the vectors that transmit Ehrlichiosis infection
c) The infection represents an Intracellular inclusion called morulae
d) The drug of choice is penicillin

6) Which of the following bacterial zoonotic diseases resembling the symptoms of influenza and pneumonia is transferred to humans through goats, sheep, and other cattle?
a) Rocky mountain fever
b) Q fever
c) Dengue fever
d) Yellow fever

7) ….................... causes endemic typhus or murine typhus which is transmitted to humans primarily through rats and cats' fleas.
a) Rickettsia prowazekii
b) Rickettsia rickettsiae
c) Coxiella burnetii
d) Rickettsia typhi

8) What is the most widely used serological test for the diagnosis of the Rickettsia rickettsiae from skin biopsy?
a) Complement fixation test
b) Immunofluorescence technique
c) Schick skin test
d) Agglutination test

9) What is the drug regimen used in the treatment of chronic Q fever?
a) Combination therapy with doxycycline and hydroxychloroquine for up to 18 months
b) Doxycycline for 18 months
c) Combination therapy with penicillin and fluoroquinolones for 12 months
d) Antibiotics do not work in this phase of illness

10) Which of the following statements is mostly correct about the antigenic forms of Coxiella burnetii?
a) The antigens exist in two phases 1 and 2 of which phase one is a virulent form
b) The antigens are less pathogenic when grown in laboratory animals
c) Both a and b
d) None of the above


11) Which of the following diseases is NOT a tick-borne disease?
a) Epidemic typhus
b) Rocky mounted spotted fever
c) Tularemia
d) Ehrlichiosis

12) All of the following are the general features, signs, and symptoms of the Scrub typhus disease caused by Rickettsia spp, EXCEPT?
a) An Eschar ulcer appears at the site of the mite bite
b) Respiratory infections are frequent
c) Lymphadenopathy is common
d) The causative agent is Rickettsia australis

13) .......................also called recrudescent typhus, it is a late relapse of epidemic typhus showing reoccurrence of symptoms similar to the previous infection and can be transmitted from one individual to others.
a) Rickettsialpox
b) Scrub typhus
c) Brill-Zinsser disease
d) Murine typhus

14) Which of the following are the reservoirs of the flea causing endemic typhus?
a) Rats
b) Dogs
c) Ticks
d) Mites

15) Which of the following is NOT the proper preventive method to control rickettsial infections?
a) Use of insecticides to control vectors and reservoirs
b) Elimination of rats and mites
c) Proper hygiene and cleanliness to eliminate lice and fleas
d) Use of sulfonamides for the treatment of epidemic and endemic typhus infections


Multiple Choice Answers Review
1-a) Epidemic typhus & b) Scrub typhus group
2-d) It is caused by the pathogen Rickettsia typhi
3- b) Rickettsia akari
4-c) Fever and Skin rashes develop within 6 hours of the ticks' bite 

5-d) The drug of choice is penicillin
6-b) Q fever
7-d) Rickettsia typhi
8-b) Immunofluorescence technique
9-a) Combination therapy with doxycycline and hydroxychloroquine for up to 18 months
10-b) The antigens are less pathogenic when grown in laboratory animals
11-b) Rocky mounted
12-d) The causative agent is Rickettsia australis
13-c) Brill-Zinsser disease
14-a) Rats
15-d) Use of sulfonamides for the treatment of epidemic and endemic typhus infections

9) Which of the following is the drug of choice for infections caused by Pasteurella multocida?
a) Ampicillin
b) Tetracyclines
c) Penicillin G
d) Doxycycline

10) Which of the following is NOT the possible pathogen isolated from infections of the human genital tract and of newborns?
a) Treponema pallidum
b) Toxoplasma gondii
c) Pasteurella bettyae
d) Campylobacter jejuni

11) The asymptomatic individuals in exposure to untreated people with pneumonic plague and laboratory personnel working with handling the specimens should be given the antibiotic prophylaxis for a given period of time, what is the drug usually used for the prophylaxis?
a) Rifampin
b) Penicillin
c) Erythromycin
d) Doxycycline

12) All of the following are the possible laboratory methods used for the diagnosis of Bubonic plague, EXCEPT
a) Blood culture on MacConkey agar
b) Stool culture on Chocolate agar
c) Aspirates culture in brain heart infusion broth taken from swollen lymph nodes
d) Wayson stain method for the identification of the suspected bacteria

13) All of the statements given below are correct about the diagnosis of Yersinia pseudotuberculosis related infection in humans, EXCEPT
a) Appendicitis-like symptoms may be observed
b) Presented as mesenteric lymphadenitis
c) Tuberculosis like symptoms may be seen in laboratory animals after bacterial inoculation
d) Genetic features are similar to Yersinia enterolitica

14) Which of the following species of Pasteurella is present as normal flora of respiratory tract and guts of mice and rats?
a) Pasteurella pneumotropica
b) Pasteurella bettyae
c) Pasteurella multocida
d) Pasteurella anatis

15) In addition to membrane lipopolysaccharide endotoxins, Yersinia pestis possesses other virulent plasmids. They include
a) pPCP1 that encodes for a plasminogen-activating protease
b) pFra/pMT that encodes for a capsular protein that has antiphagocytic activity
c) pFra/pMT that encodes for phospholipase D crucial for survival in flea gut
d) All of the above
Multiple Choice Answers

1-d) Leishmania tropica
2-b) Bubonic plague
3-c) The colonies appear as lactose positive on MacConkey agar
4-All of the above a, b,c, d
5-c) The most common serotypes causing human gastroenteritis is O:1
6-c) Doxycycline with aminoglycoside
7-b) Celfsulodin-irgasan-novobiocin agar
8-b) Pasteurella multocida
9-d) Doxycycline
10-d) Campylobacter jejuni
11-d) Doxycycline
12-b) Stool culture on Chocolate agar
13-d) Genetic features are similar to Yersinia enterolitica
14-a) Pasteurella pneumotropica
15-d) All of the above

3) During the B cell maturation, which of the following stage expresses surrogate light chain complexed with the heavy chain?
a) Pro-B cell
b) Pre-B cell
c) Immature B cell
d) Mature B cell

4) Which of the following cell surface marker is not expressed through the B cell maturation from Pro B cell to Mature B cell?
a) CD19
b) Igα/Igβ
c) CD24
d) IgD/IgM

5) During the pre-B cell stage of the maturation process, the µ heavy chain rearrangement is followed by the light chain. Which of the following statements are correct EXCEPT
a) Once the heavy chain is synthesized surrogate light chain forms complex
b) The surrogate light chain/heavy chain complex formation signals are required for light chain rearrangement
c) The surrogate light chain/heavy chain complex signals prevent rearrangement of other heavy chains and enable allelic exclusion
d) The surrogate light chain remains in complex with a heavy chain until B cell maturation

6) B1 B cells are self-renewing B cell subset. Which of the following is true regarding B1 B cells?
a) B1 B cells compose of 95% of the total B cell population
b) B1 B cells express numerous IgD molecules in their cell surface
c) CD5 is an indispensable component of the B1 lineage
d) B1 population responds poorly to carbohydrate antigens

7) Thymus-independent antigens activate B cells without the help of T-helper cells. These molecules include
a) Lipids
b) Lipopolysaccharides
c) Polysaccharides
d) Proteins

8) Which of the following is correct regarding the activation of B cells by thymus-independent antigens (TI)?
a) Exposure of TI antigen leads to a weaker response than thymus-dependent (TD) antigens.
b) The activation of B cell results in secretion of IgMs
c) TI antigens may serve as mitogens for B cell proliferation
d) All of the above

9) Which of the following is not true regarding thymus-dependent (TD) antigens?
a) Induce isotype switching
b) Induce affinity maturation
c) Possess immunological memory
d) Always induce polyclonal activation of B cells

10) In addition to the primary signal generated for antigen binding to B cell receptor, the thymus-dependent B cell activation requires a secondary signal. The second signal is provided by
a) Igα/Igβ
b) B cell CD40 interaction with T cell CD40L
c) CD 8 interaction with MHC molecule
d) None of the above

11) The B cell receptors interact with the B cell co-receptors for effective signaling. What is the component of the B cell coreceptor complex?
a) CD19, CD 21 (CR 2) & CD81
b) CD19, CD45 & CTLA-4
c) CD10, CD22 & CD81
d) None of the above

12) Which of the following cell surface marker constitutively expressed on B cells that deliver a negative signal for B cell activations?
a) CD22
b) CD40
c) Igα
d) Igβ

13) A patient presented with a history of recurrent respiratory tract infection, and exhibited reduced concentration of all classed of immunoglobulins. The genetic testing shows a mutation of RAG1 & RAG2 genes. What are the function of RAG1 and RAG2 proteins?
a) Signal B cell activation
b) Rearrange heavy chains of immunoglobulins
c) Inducing Affinity maturation
d) Induce Isotype switching

14) Omenn syndrome is characterized by the presence of pruritic skin, fever, lymphadenopathy, anemia, and eosinophilia. Which of the following condition may present as Omenn syndrome?
a) RAG gene deficiency
b) X-linked CD40 ligand deficiency
c) CD40 deficiency
d) None of the above

15) A patient visited a hospital with a recurrent sinopulmonary infection. The laboratory evaluation showed a marked deficiency of circulating B lymphocytes, decreased immunoglobulin level. The genetic testing showed the mutation of brk gene. What is the function of brk gene?
a) Brk is involved in isotype class switching
b) Brk is tyrosine kinase that functions BCR signaling pathway
c) Brk is involved in affinity maturation
d) All of the above

Multiple Choice Question Answers
1)- d) CD45R
2)- c) Both of the above
3)- b) Pre-B cell
4)- d) IgD/IgM
5)- d) The surrogate light chain remains in complex with a heavy chain until B cell maturation
6)- c) CD5 is an indispensable component of the B1 lineage
7)- d) Proteins
8)- d) All of the above
9)- d) Always induce polyclonal activation of B cells
10)- b) B cell CD40 interaction with T cell CD40L
11)- a) CD19, CD 21 (CR 2) & CD81
12)- a) CD22
13)- b) Rearrange heavy chains of immunoglobulins
14)- a) RAG gene deficiency
15)- b) Brk is tyrosine kinase that functions BCR signaling pathway