Preparatory Guide on Biochemistry, Molecular Biology, Physiology, Microbiology, Immunology, Pharmacology & Drug Discovery

Immunology: Antigen Processing and Presentation MCQ

January 27, 2019
Multiple Choice Question on Antigen Processing and Presentation

1) The cells that display peptides associated with class II MHC molecules to CD4+ Th cells are called antigen presentation cells. Which of the following is not professional antigen presenting cells
a) Dendritic cells
b) Macrophages
c) B cells
d) Fibroblast

2) The professional antigen presenting cells different antigen uptake, constitutive MHC expression, and co-stimulatory activity. Which of the following is true
a) Dendritic cells constitutively express a high level of class II MHC molecules and co-stimulatory activity, they can activate naïve T cells.
b) Macrophage must be activated by phagocytosis of particular antigens before they express class II MHC molecules or co-stimulatory B-47 membrane molecules
c) B cells constitutively express class II MHC molecules but must be activated before they express the co-stimulatory signal
d) All of the Above


3) The antigenic peptide derived by class I are derived from endogenous processing pathway. The researcher performed exposure of different antigens and obtained the following results. Emetine is a protein synthesis inhibitor and Chloroquine inhibits endocytosis pathway.

Exposure Condition
MHC I restricted T-cell activation
Infectious Virus
+
Inactivated Non-infectious virus
-
Infectious virus + Emetine
-
Infectious virus + Cholorquine
+
Which of the following options is the correct answer?

a) MHC class I antigen presentation requires active infectious virus
b) The viral protein synthesis is required for MHC-Class I- peptide presentation
c) The endocytic pathway is not required for MHC-class I restricted activation
d) All of the above

4) The peptides for presentation on MHC-I are generated by protease complex called proteasome.
a) The peptides are targeted for proteolysis with the attachment of ubiquitin
b) Ubiquitin-protein conjugate are recognized and degraded by a complex called proteasome
c) The proteasome-mediated proteolysis is ATP dependent
d) All of the above

5) The antigenic peptide derived by class II is derived from exogenous processing pathway. The researcher performed exposure of different antigens and obtained the following results. Emetine is a protein synthesis inhibitor and Chloroquine inhibits endocytosis pathway.

Exposure Condition 
MHC II restricted T-cell activation
Infectious Virus
+
Inactivated Non-infectious virus
+
Infectious virus + Emetine
+
Infectious virus + Cholorquine
-

Which of the following options is the correct answer?
a) MHC class II presentation does not require active virus
b) The endogenous viral protein synthesis is not required for MHC-II peptide presentation
c) Inhibition of endocytic pathway hinders MHC class II-restricted T cell activation
d) None of the above

6) Transporter associated with antigen processing (TAP) is involved in the transport of the antigenic peptide from cytosol to endoplasmic reticulum. Which of the following the correct answer?
a) TAP 1 & TAP 2 are class of ABC binding cassette proteins required for transport of processed peptide and they are highly polymorphic
b) TAP has the highest affinity for a peptide containing 8-10 amino acids and favors hydrophobic amino acids
c) Define mutation of TAP proteins lead to immunodeficiency and autoimmunity
d) All of the above

7) The chaperone is associated with free class Iα chain facilitate its folding and release after binding to β2 macroglobulin is
a) Calnexin
b) Calreticulin
c) Tapasin
d) Ubiquitin

8) Which of the following chaperones are bound to MHC class Iα chain and β2 microglobulin and facilitate the formation of MHC- class Iα, β2 microglobulin, and antigenic peptide trimers?
a) Calnexin & Calreticulin
b) Calreticulin & Tapasin
c) Calnexin & Tapasin
d) Calnexin & Ubiquitin

9) Which of the following mechanism is involved in the internalization of antigen by B cells?
a) Pinocytosis
b) Phagocytosis
c) Receptor-mediated endocytosis
d) All the above
10) Cholorquine is an inhibitor of the endocytic processing which
a) inhibits peptide uptake into cells
b) allosterically inhibit lysosomal proteases
c) increases the pH of lysosome and inactivation of lysosomal proteases
d) None of the above

11) Before loading of antigenic peptide, MHC molecules exist in
a) monomers of α and β chain
b) dimers with an empty peptide-binding site
c) Trimers with peptide binding site with class II-associated invariant peptide
d) None of the above

12) Which of the following non-classical MHC molecule is required for the catalysis of exchange of CLIP peptide with antigenic peptide
a) HLA-DI
b) HLA- DM
c) HLA-DQ
d) HLA-DO

13) Which of the following non-classical MHC molecule impede the exchange of CLIP peptide with antigenic peptide
HLA-DI
HLA-DM
HLA-DQ
HLA-DO
14) Which of the following is not the characteristic feature of HLA DM
a) The HLA-DM is widely conserved among mammalian species
b) HLA is not polymorphic
c) HLA DM is present in the endosome
d) HLA is present in the cell surface

15) In B cell, the receptor that mediates the endocytosis of antigen is
a) MHC-II molecule
b) Membrane-bound antibody
c) CD41 antigen
d) CD20 antigen

16) The fate of the B-cell receptor that mediates antigen endocytosis is
a) The antigen is endocytosed and receptor remains at the surface
b) Both antigen and receptor are endocytosed but the receptor is recycled to the cell surface
c) Both antigen and receptor, processed and degraded
d) None of the above

17) Which of the following is true for the antigenic peptide that is presented via MHC class I and MHC class II?
a) They are non-covalently but stably bound to MHC
b) They are covalently bound to the MHC
c) The antigen peptide dissociate from MHC once it reaches the cell surface
d) The antigen can be replaced by other peptides on the cell membrane

18) The properties of CD1, a non-classical pathway for antigen presentation is
a) Similar to MHC class I, CD1 interacts with β2 microglobulin
b) The genes are located in chromosome 1
c) The antigen binding site for CD1 is deeper and voluminous
d) All of the above

19) CD1 is mainly involved in the presentation of …………………….. and activation of T cells
a) Peptides
b) Lipopolysaccharides
c) Both
d) None
20) What is the characteristic feature of TAP deficiency?
a) Increased NK cells
b) Increased CD8+ T cells
c) Increased MHC class I expression cell surface
d) None of the above

Multiple Choice Answers Review 
1-d) Fibroblast
2-b) Macrophage must be activated by phagocytosis of particular antigens before they express class II MHC molecules or co-stimulatory B-47 membrane molecules
3-c) The endocytic pathway is not required for MHC-class I restricted activation
4- d) All of the above
5- d) None of the above
6-d) All of the above
7-a) Calnexin
8-b) Calreticulin & Tapasin
9-c) Receptor-mediated endocytosis
10-c) increases the pH of lysosome and inactivation of lysosomal proteases
11-c) Trimers with peptide binding site with class II-associated invariant peptide
12-b) HLA- DM
13- c) HLA-DQ
14- d) HLA is present in the cell surface
15-b) Membrane-bound antibody
16-b) Both antigen and receptor are endocytosed but the receptor is recycled to the cell surface
17- a) They are non-covalently but stably bound to MHC
18-d) All of the above
19-b) Lipopolysaccharides
20-a) Increased NK cells


Immunology: Antigen Processing and Presentation MCQ Immunology: Antigen Processing and Presentation MCQ Reviewed by Biotechnology on January 27, 2019 Rating: 5

Medical Microbiology: Neisseria gonorrhoeae and Neisseria meningitidis MCQ

January 24, 2019
Multiple Choice Question on Neisseria species

1. All are the cultural characteristics of gram-negative diplococcus Neisseriae spp, EXCEPT
a) Grow in aerobic as well as anaerobic conditions
b) They are oxidase positive
c) Grow on media containing heated blood
d) Growth is improved by incubation in the presence of 20 to 25 % CO2

2. Neisseria gonorrhoeae is one of the most common causes of sexually transmitted diseases. All of the following are the infections caused by N. gonorrhoeae, EXCEPT
a) Genital gonorrhea in women
b) Pelvic inflammatory disease in men
c) Neonatal conjunctivitis
d) Pharyngitis

3) Beta lactamase positive strains of Neisseria gonorrhoeae are highly resistant to tetracycline because
a) Beta lactamase production and high-level resistance to tetracycline are both mediated by genes on plasmids
b) Beta lactamase production and high-level resistance to tetracycline are both mediated by genes on the bacterial chromosome
c) Beta lactamase production is mediated by genes on plasmids and high-level tetracycline is mediated by genes on the bacterial chromosome
d) Beta lactamase production is mediated by genes on the bacterial chromosome and high-level tetracycline is mediated by genes on plasmids

4) All, except one, are the examples of protein present in the antigenic structure of Neisseria gonorrhoeae that helps the bacteria to invade a host cell
a) Por proteins
b) Rmp proteins
c) Opa proteins
d) IgM protease

5) …....................... is not an antimicrobial drug added in the culture media for the isolation of Neisseria gonorrhoeae
a) Penicillin
b) Vancomycin
c) Amphotericin
d) Colistin

6) Which statement is true about the Nucleic Acid Amplification Tests used for the direct detection of Neisseria gonorrhoeae in genitourinary specimen?
a) This test has low sensitivity and specificity in symptomatic and high prevalence populations
b) This test has equal sensitivity and specificity as Neisseria gonorrhoeae in symptomatic and high prevalence populations
c) This test has high sensitivity and specificity in symptomatic and high prevalence populations
d) This test has high sensitivity and low specificity in symptomatic and high prevalence populations

7) Among the serogroups of Neisseria meningitidis given, which of these are the most important associated with meningococcal infection?
a) A, B, C, Y and W135
b) A, B, C, X, Y and W135
c) A, B, C, X, Y and W125
d) A, B, C, X and W135

8) The meningococcal infections are predominant in which of the following age group?
a) Infants only
b) Children and Young adults
c) Adults only
d) Children and Adults

9) About 10 to 20 percent of young children with the severe meningococcal meningitis develop a syndrome called Waterhouse friderichsen syndrome, which one of these is not the symptomatic characteristic of this syndrome?
a) High fever
b) Hemorrhagic rashes
b) Circulatory collapse
d) Disseminated cerebral coagulation

10) Which of the following antigenic structure is considered the major virulence factor in the pathogenesis of Neisseria meningitidis?
a) Polysaccharide capsule
b) Pili
c) Porin
d) Opa protein

11) What component may not be required for the culture of blood specimens taken from the meningococcal infection patient?
a) Sodium sulfonate
b) Sodium gluconate
c) Sodium polyanethol sulfonate
d) Sodium polyascorbate

12) What is/are the serological tests to measure antibodies to meningococcal polysaccharide?
a) Latex agglutination test
b) Hemagglutination test
c) Latex and hemagglutination tests
d) None of the above

13) What is the drug of choice for the treatment of meningococcal disease?
a) Penicillin
b) Amphotericin
c) Methicillin
d) Penicillin G

14) Which of the following individuals should routinely receive vaccination with the conjugate meningococcal vaccine?
a) A 40-year-old man with diabetes
b) A healthy boy going to kindergarten
c) A healthy 65-year-old man with diabetes
d) A healthy young adolescent entering high school

15) Which one of the following tests can be useful to differentiate between Moraxella catarrhalis and saprophytic Neisseria spp from sputum specimen?
a) Oxidase
b) Butyrate esterase
c) Gram stain
d) Catalase

Multiple Choice Question Answers
1 (d), 2 (b), 3 (a), 4 (d), 5 (a), 6(c), 7 (b), 8 (b), 9 (d), 10 (a), 11 (c), 12 (c), 13 (d), 14 (d), 15 (b)
Medical Microbiology: Neisseria gonorrhoeae and Neisseria meningitidis MCQ Medical Microbiology: Neisseria gonorrhoeae and Neisseria meningitidis MCQ Reviewed by Biotechnology on January 24, 2019 Rating: 5

Medical Microbiology: Vibrios, Campylobacter and Helicobacter MCQ

January 11, 2019
Multiple Choice Question on Vibrios, Campylobacters, Helicobacter

1) A stool specimen from 5 years old child is cultured in selective media having high pH concentration. After the incubation, colonies appear smooth and round and identified as a comma-shaped, gram-negative, motile bacteria. Name the bacteria isolated?
a) Aeromonas spp
b) Pseudomonas aeruginosa
c) Streptococcus pyogens
d) Vibrio cholerae

2) Vibrio cholerae causes Cholera and mostly occurs in developing countries, symptoms include diarrhea and vomiting within 2-3 days after the ingestion of contaminated water or food. Name the type of diarrhea caused by V.cholerae?
a) Acute watery diarrhea with blood
b) Acute watery diarrhea resembling rice water
c) Mild watery diarrhea resembling rice water
d) Acute watery diarrhea with no blood

3)What is the most common food that causes foodborne gastro-enteritis by Vibrio parahaemolyticus?
a) Chicken
b) Fish
c) Oysters
d) Rice

4) Which of the following statements is/are not correct about Aeromonas spp and Plesiomonas spp?
a) Both are oxidase positive
b) They can be found in freshwater and soil
c) They are gram-negative rods
d) Grow well on TCBS (thiosulphate citrate bile salt) media

5) Campylobacter jejuni is one of the most common causes of food poisoning, which also has been associated with post diarrheal syndrome, the syndrome is called..........…......?
a) Toxic shock syndrome
b) Guillain-Barre syndrome
c) Short bowel syndrome
d) Rett syndrome

6) Campylobacter jejuni is a microaerophilic bacteria, which of the following statement is true for the culture of this bacteria?
a) An atmosphere of increased O2 (10%) with added CO2 (5%)
b) An atmosphere of reduced O2 (5%) with added CO2 (10%)
c) An atmosphere of reduced CO2 (5%) with added CO2 (10%)
d) An atmosphere of increased CO2(10%) with added O2 (5%)

7) What is/are not the growth characteristics of Campylobacter spp? Select from all the options given below.
a) Oxidase and catalase positive
b) Produce H2S
c) Ferment carbohydrates
d) Have darting motility

8) Helicobacter pylori is associated with all of the following, EXCEPT?
a) Malt lymphoma
b) Gastric carcinoma
c) Peptic ulcer
d) Burkitt lymphoma

9) Which one of the following virulence factors may be associated with the pathogenesis of infection caused by Helicobacter pylori?
a) Flagella
b) Lipopolysaccharides
c) Exotoxins
d) Endotoxins

10) Which one of these is not the common laboratory tests for the identification of Helicobacter pylori?
a) Biopsy test
b) Urease breath test
c) Stool antigen test
d) Urine test

11) Which of the following biotypes of Vibrio cholerae is prevalent in developing countries?
a) EL Tor
b) Classic
c) Biotype 0139
d) Biotype 139

12) Aeromonas hydrophila mostly causes infections to fish and amphibians and less pathogenic to humans, one of the most common infection in human is gastroenteritis. What is the other common human disease caused by bacteria?
a) Peptic ulcer
b) Cellulitis
c) Asthma
d) Gastritis

13) Helicobacter pylori infection is most prevalent in developing countries, in what age people the chances of infection is the highest?
a) 10 to 30
b) 30 to 50
c) 60 and above
d) Infant

14) Vibrio vulnificus and V. parahaemolyticus both gram-negative, motile bacteria are mostly found in warm coastal areas. What is/are the common source through which these bacteria can be transferred to human and cause infections?
a) Water
b) Oysters
c) Shellfish
d) All of the above

15) …............... is less likely to cause gastroenteritis or diarrheal disease in humans.
a) Vibrio spp
b) Salmonella spp
c) Plesiomonas spp
d) Campylobacter spp

Multiple Choice Answers Review
1-d) Vibrio cholera
2-b) Acute watery diarrhea resembling rice water
3-c) Oysters
4-d) Grow well on TCBS (thiosulphate citrate bile salt) media
5-b) Guillain-Barre syndrome
6-b) An atmosphere of reduced O2 (5%) with added CO2 (10%)
7- c) Ferment carbohydrates
8-d) Burkitt lymphoma
9-d) Endotoxins
10-d) Urine test
11- a) EL Tor
12-b) Cellulitis
13-c) 60 and above
14-d) All of the above
15-c) Plesiomonas spp

Medical Microbiology: Vibrios, Campylobacter and Helicobacter MCQ Medical Microbiology: Vibrios, Campylobacter and Helicobacter MCQ Reviewed by Biotechnology on January 11, 2019 Rating: 5

Immunology: MHC Structure, Gene arrangement & Function: MCQ

January 06, 2019
Multiple Choice Questions MHC Structure, Gene arrangement & Function 

1) Major histocompatibility complex (MHC) gene polymorphism and alleles are associated with increased susceptibility of certain diseases. One of the allele, B47 which is associated with
a) Ankylosis spondylitis
b) Reactive arthritis
c) Reiter’s syndrome
d) All of the above

2) Hereditary hemochromatosis is a disorder characterized by iron overload liver and other tissues. Which of the MHC allele is associated with the highest relative risk for hereditary hemochromatosis?
a) A13/B14 co-incidence
b) B12/A3 co-incidence
c) A3/B14 co-incidence
d) None of the above

3) Narcolepsy is a chronic neurological disorder that affects brain ability to control the sleep-wake cycle. Which of the follow MHC allele is associated with it?
a) DR1
b) DR2
c) DR3
d) DR4

4) Systemic lupus erythematosus is an autoimmune disorder characterized by chronic and systemic inflammation due to loss of immune tolerance against nuclear autoantigen. The MHC allele associated with the susceptibility include
a) DP beta 1
b) DQ beta 1
c) DR beta 1
d) None of the above

5) Major Histocompatibility Complex (MHC-I) molecules are the cell surface proteins activates T cells and mediate effector T-cell function. Which of the following class of MHC molecules activate cytotoxic T cells?
a) MHC class I
b) MHC class II
c) MHC class III
d) All of the above

6) The MHC molecules are encoded by the specific genes. Which of the following is an incorrect statement regarding MHC genes:
a) MHC class I proteins are encoded by B, C & A genes
b) MHC class II proteins are encoded by DP, DQ and DR genes
c) Both MHC class I and MHC class II genes are present in the same region of chromosome
d) MHC class I and MHC class II are encoded by genes located in the different region of chromosomes

7) The MHC proteins are highly polymorphic. The following factors contribute to the polymorphism, EXCEPT
a) MHC proteins are present in haplotypes
b) MHC are co-dominantly expressed
c) MHC genes are highly conserved
d) None of the above

8) Which of the following statement is FALSE regarding MHC proteins
a) MHC class I is a dimer consisting of two chains: one alpha chain (three subunits) and b2 microglobulin chain expressed outside the cell membrane
b) MHC class I is a dimer consisting of two chains: an alpha and a beta-chain each consisting of two subunits expressed outside the cell membrane
c) Both of the above
d) None of the above

9) Beta2 microglobulin is a highly conserved subunit essential for expression of class I on the cell surface. Identify the correct statement regarding Beta2 microglobulin gene
a) It is located on the same chromosome as B, C, A genes
b) It is located in a different chromosomal location than B, C, and A genes
c) It is a part of MHC I gene cluster
d) None of the above

10) The following is the characteristic feature of peptide binding cleft for MHC class I proteins
a) It consists of alpha 1 and alpha 2 subunits
b) The pocket can bind to 8-10 amino acid peptide
c) It is close-ended pocket
d) All of the above

11) The anchor residues are mostly present in the c-terminal end of the peptide and bind to the amino acid residue on the peptide binding cleft. The anchor residues are
a) Acidic amino acid
b) Basic amino acids
c) Hydrophobic amino acids
d) None of Above

12) The CD8 cell surface protein of T cells interact with …………….. of MHC class I molecules.
a) alpha-1 subunit
b) alpha-2 subunit
c) alpha-3 subunit
d) beta2- microglobulin

13) Interferon-gamma is a cytokine that induces the expression of
a) MHC class I
b) MHC class II
c) Both of Above
d) None of Above
14) The MHC expression is decreased by infection of some viruses namely
a) Human Cytomegalovirus
b) Hepatitis Virus
c) Adenovirus 12
d) All of the above
15) Many viruses produce a protein immunoevasin that interfere with antigen presentation by MHC class I molecules. The immunoevasin interfere MHC presentation by
a) Block peptide transport to TAP
b) Inhibiting E3 ubiquitin ligase activity
c) Block tapasin function
d) All of the above

16) The antigen recognition by T cell depends on the presence of specific MHC molecules in the antigen presenting cell which is known as
a) MHC-recognition
b) MHC-restriction
c) MHC-processing
d) MHC-signaling

17) Which of the following gene is not the part of MHC class I gene cluster
a) TAP gene
b) Tapasin gene
c) Proteasome LMP gene
d) TNF gene

18) MHC molecules are necessary for T cell response. Which of the following function is mediated by MHC-T cell interaction?
a) Immune Tolerance
b) Cytotoxicity
c) B-cell activation
d) All of the above

19) The following is the characteristic feature of peptide binding cleft for MHC class II proteins
a) It is formed by alpha1 and beta1 interaction
b) The pocket binds to 13-18 amino acids
c) MHC-II has open-ended peptide binding cleft
d) All of the above

20) The CD4 protein of T helper cells bind and stabilizes the MHC class II/peptide structure. The subunit that interacts with CD4 cell surface protein is
a) alpha1 and beta1 subunit
b) alpha2 and beta2 subunits
c) alpha1 and alpha2 subunits
d) beta1 and beta2 subunits

21) Bare lymphocytes are the genetic disorder caused by a lack of class II molecules on the cell surface. This is associated with
a) Mutation of the gene encoding MHC class II proteins
b) The mutation that leads to MHC folding
c) Mutation of transcription factor protein (CIITA) required for expression of MHC class II proteins
d) None of the above
Multiple Choice Answers Review
1-d) All of the above
2-c) A3/B14 co-incidence
3-c) DR3
4-c) DR beta 1
5-a) MHC class I
6-c) Both MHC class I and MHC class II genes are present in the same region of chromosome 7-c) MHC genes are highly conserved
8-d) None of the above
9-b) It is located in the different chromosomal location than B, C, and A genes
10-d) All of the above
11-c) Hydrophobic amino acids
12-c) alpha-3 subunit
13-c) Both of Above
14-d) All of the above
15-d) All of the above
16-b) MHC-restriction
17- d) TNF gene
18-d) All of the above
19-d) All of the above
20- d) beta1 and beta2 subunits
21-c) Mutation of transcription factor protein (CIITA) required for expression of MHC class II proteins
Immunology: MHC Structure, Gene arrangement & Function: MCQ Immunology: MHC Structure, Gene arrangement & Function: MCQ Reviewed by Biotechnology on January 06, 2019 Rating: 5

Immunology: Antibody Gene Structure and Diversity MCQ

January 06, 2019
Antibody Diversity: Multiple Choice Questions

1) Antibodies are produced by plasma cells differentiated from plasma cells and committed towards specific antibodies. Which of the following statement is TRUE regarding the genes for these antibodies?
a) The specificity of the antibodies is predetermined by the set of genes before exposure to antigen.
b) The diversity is governed by the set of separate genes i.e. each gene encodes for its specific antibodies.
c) The antibody is encoded by the multi-gene family for the heavy and light chain and its rearrangement confers the diversity.
d) None of the above

2) The light chains are encoded by either kappa or lambda genes. These genes consist of different segments that encode for the variable and constant domain. They are:
a) C-J-V
b) V-J-C
c) J-V-C
d) None of the above

3) The heavy chains are encoded by the genes consisting of different DNA segments that encode for the variable, and the constant region. They are:
a) C-J-D-V
b) C-D-J-V
c) V-J-D-C
d) V-D-J-C

4) The rearrangement of antibody genes is the orderly process. During the gene expression, which of the following segment undergo first gene arrangement?
a) The heavy chain constant region that determines the isotype
b) Heavy chain variable region that determines antibody specificity
c) The light chain constant region that provides the backbone
d) Light chain variable region that determines antibody specificity

5) Which of the following is the sequential process of gene arrangement of kappa light chain of antibody?
a) VJ joining --> Transcription --> Alternative RNA splicing --> VJC joining --> Translation
b) Transcription --> VJ joining --> Alternative RNA splicing --> VJC joining --> Translation
c) Transcription --> Alternative RNA splicing --> VJ joining --> VJC joining --> Translation
d) None of the above


6) Which of the following is the sequential process of gene arrangement of the heavy chain of antibody?
a) Transcription --> DJ- joining --> VDJ joining -->Alternative RNA splicing --> Translation
b) VJ- joining --> VDJ joining -->Transcription --> Alternative RNA splicing --> Translation
c) DJ- joining --> VDJ joining -->Transcription --> Alternative RNA splicing --> Translation
d) None of the above

7) In human, the gene that encodes for heavy chain is present in chromosome:
a) 2
b) 14
c) 22
d) None of the above

8) In humans, the genes that encode for kappa light chain is present in chromosome:
a) 2
b) 14
c) 22
d) None of the above

9) In humans, the genes that encode for lambda light chain is present in chromosome:
a) 2
b) 14
c) 22
d) None of the above

10) In mice, the genes that encode for the heavy chain is present in chromosome:
a) 6
b) 12
c) 16
d) None of the above

11) The recombination and gene arrangement occurs at the site which consists of unique conserved sequence known as a recombination signal sequence. It consists of
a) GC rich nucleotide sequence
b) AT rich nucleotide sequence
c) AG rich nucleotide sequence
d) Poly A nucleotide sequence

12) The recombination and gene arrangement requires two proteins known as RAG-1 and RAG-2. What is the function of RAG-1 &RAG-2 protein?
a) They catalyze the cleavage of one strand of the DNA
b) They catalyze the cleavage of both strand of the DNA
c) They catalyze the addition of 15 nucleotides in the junction
d) None of the above

13) In membrane-bound IgM molecules, the transmembrane and cytoplasmic segments are encoded by which of the following exons
a) CH3 & CH4 exons
b) M1 and M2 exons
c) M1 and C1 exons
d) None of the above

14) Which of the following antibodies may be co-expressed by the B-cells?
a) IgM and IgA
b) IgM and IgD
c) IgG and IgD
d) IgG and IgE

15) The assembly of light and heavy chain into disulfide and glycosylated immunoglobulin occurs in the rough endoplasmic reticulum. What is the order of assembly for IgM?
a) Assembly of two heavy chains (HH) followed by light chain (LL) and H2L2
b) Assembly of one heavy chain and light (HL) followed by H2L2
c) Assembly of two heavy chains (HH) followed by light chain H2L and H2L2
d) All of the above

16) The assembly of light and heavy chain into disulfide and glycosylated immunoglobulin occurs in the rough endoplasmic reticulum. What is the order of assembly for IgG?
a) Assembly of two heavy chains (HH) followed by light chain (LL) and H2L2
b) Assembly of one heavy chain and light (HL) followed by H2L2
c) Assembly of two heavy chains (HH) followed by light chain H2L and H2L2
d) All of the above

17) Which of the following transcription factor binds to the immunoglobulin promoter
a) E2B
b) Myc
c) Rb2
d) Oct1

18) Chimeric humanized monoclonal antibodies are generated using
a) Hybridoma technology
b) Recombinant DNA technology
c) Southern blot
d) Hyperimmunization

19) Which of the following results in the diversity of the antibodies?
a) Somatic hypermutation
d) Association of light and heavy chain
c) V-D-J joining
d) All of the above

20) Which of the following is true regarding the expression of immunoglobin?
a) The genes from both parents are expressed in a cell
b) The genes from one parent are expressed in a cell
c) The H and L genes are randomly derived from either parent
d) None of the above
Multiple Choice Questions Answers
1)-c, 2)-b, 3)-d, 4)- b, 5)-a, 6)-c, 7)-b, 8)-a, 9)-c, 10-b,

11)-b, 12)-a, 13)-b, 14)-b, 15)- a, 16)-c, 17)-d, 18)-b, 19)-d, 20)-b


Immunology: Antibody Gene Structure and Diversity MCQ Immunology: Antibody Gene Structure and Diversity MCQ Reviewed by Biotechnology on January 06, 2019 Rating: 5

Medical Microbiology: Pseudomonas & Acinetobacter and Other Uncommon Gram Negatives MCQ

January 06, 2019
Multiple Choice Question on Pseudomonas & Acinetobacter
1) Which one of the given statements is not true about Pseudomonads?
a) Rod-shaped, often curved
b) Motile
c) Found in soil and water and plants
d) All species cause diseases in humans only

2) Pseudomonas aeruginosa produces a water-soluble blue color pigment called pyocyanin and …............ color pigment pyoverdin.
a) Green
b) Blue-green
c) Red
d) Pink-red

3) Patients with cystic fibrosis infection suffer from a chronic lung infection caused by Pseudomonas aeruginosa. The bacterial growth results in …........formation and clogs the lung airways.
a) Pigment
b) Biofilm
c) White blood cells
d) Endotoxin

4) Isolation of Pseudomonas aeruginosa from a mucoid sputum specimen obtained from a patient with cystic fibrosis is usually done by standard culture method. After the incubation, mucoid bacterial colonies can be seen on the agar media which have a grape-like odor, what are the best growth temperature and incubation period for the given bacteria?
a) 42 degree Celsius for 48 hours
b) 37 degree Celsius for 48 hours
c) 42 degree Celsius for 24 hours
d) 37 degree Celsius for 42 hours

5) All of the following statements for Pseudomonas aeruginosa are true, except;
a) It is oxidase positive
b) It does not grow well at 42c
c) It is an opportunistic pathogen
d) It contains fimbriae

7) Pseudomonas aeruginosa is frequently associated with the hospital-acquired bacterial infection, mostly affecting immunocompromised patients. Which of the following is/are example/examples of the various means by which bacteria can transfer and cause infection to the susceptible patient?
a) Healthcare workers
b) Contaminated equipment
c) Air droplets
d) All of the above

8) Multiple virulence factors play an important role in the mechanism of pathogenesis by Pseudomonas aeruginosa, one of the main virulent structural components is pili, which helps the bacteria to adhere to the cell surfaces. Which one is not the virulence factor Pseudomonas aeruginosa?
a) Hemolysins
b) Pigments
c) Phospholipase B
d) Extracellular protease

9) Apart from Pseudomonas aeruginosa, which one of the following gram-negative bacteria can be frequently associated with nosocomial infections?
a) Staphylococcus aureus
b) Candida albicans
c) Eikenella corrodens
d) Acinetobacter baumannii

10) Which one of the following is not the general characteristic of the HACEK ( Haemophilus, Aggregatibacter, Cardiobacterium, Eikinella, Kingella) organisms?
a) Normal flora of the oral cavity
b) Require CO2 for growth
c) Grow well on MacConkey agar
d) Causative agents of infectious endocarditis

11) Burkholderia pseudomallei is aerobic, gram-negative, motile, aerobic, saprophytic bacteria. It grows at 42-degree celsius in standard agar media forming mucoid colonies, cream to orange in color.
a) Pseudomonas aeruginosa
b) Burkholderia mallie
c) Acinetobacter baumannii
d) Burkholderia pseudomallei

12) Which are the most common bacteria found in a specimen taken from burned patients?
a) Streptococcus epidermis
b) Pseudomonas aeruginosa
c) Acinetobacter baumannii
d) Moraxella catarahalis

13) Acinetobacter baumannii is one of the most ............ gram-negative rod-shaped bacteria.
a) Multidrug resistant
b) Fastidious
c) Active
d) Infectious

14) Which of the following is a small, capnophilic, gram-negative, oxidase positive bacillus is frequently found in human bite infections.
a) Eikenella corrodens
b) Moraxella spp
c) Proteus vulgaris
d) Burkholderia mallie

15) Capnophiles are microorganisms that can grow in high concentrations of..............
a) Oxygen
b) Sugar
c) Carbon dioxide
d) pH

16) The isolation of this gram-negative bacteria associated with cystic fibrosis can be done by culturing the specimen in selective media containing colistin. A sputum sample is taken and cultured, colonies appear only after 72 hours of the incubation period, these bacteria are oxidase positive and further identification is done by using molecular methods, which bacteria is this?
a) Enterobacter aerogenes
b) Burkholderia cepacia
c) Pseudomonas aeruginosa
d) Acinetobacter johnsonii

17) …............is the part of the normal flora and is one of the most common causes of acute septic arthritis seen in children.
a) Moraxella catarrhalis
b) Staphylococcus saprophyticus
c) Cardiobacterium hominis
d) Kingella kingae

18) Which of the following gram-negative bacteria is a plant pathogen?
a) Pseudomonas syringae
b) Burkholderia glanders
c) Chryseobacterium spp
d) Capnocytophaga spp

19) Name the bacteria used as bioremediation agents which have the ability to degrade organic solvents such as toluene.
a) Pseudomonas syringae
b) Acinetobacter baumannii
c) Pseudomonas alcaligens
d) Pseudomonas putida

20) Pseudomonas aeruginosa is resistant to most of the antibiotics and this is mainly due to chromosomally encoded antibiotic resistance genes and the............ of the bacterial cellular envelopes.
a) Low susceptibility
b) High permeability
c) Low permeability
d) High susceptibility

Multiple Choice Answer Review
1-d) All species cause diseases in humans only
2-a) Green
3-b) Biofilm
4-a) 42 degree Celsius for 48 hours
5-d) All of the above
7-d)All of the above
8)- c) Phospholipase B
9-d) Acinetobacter baumannii
10-d) Causative agents of infectious endocarditis
11- d) Burkholderia pseudomallei
12-b) Pseudomonas aeruginosa
13-a) Multidrug resistant
14-a) Eikenella corrodens
15-c) Carbon dioxide
16-b) Burkholderia cepacia
17-d) Kingella kingae
18-a) Pseudomonas syringae
19-d) Pseudomonas putida
20-c) Low permeability





Medical Microbiology: Pseudomonas & Acinetobacter and Other Uncommon Gram Negatives MCQ Medical Microbiology: Pseudomonas & Acinetobacter  and Other Uncommon Gram Negatives MCQ Reviewed by Biotechnology on January 06, 2019 Rating: 5
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