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Msb 103:Blood And Immune Mechanism Question Paper
Msb 103:Blood And Immune Mechanism
Course:Bachelor Of Medicine And Bachelor Of Surgery
Institution: Moi University question papers
Exam Year:2007
M O I U N I V E R S I T Y
SCHOOL OF MEDICINE
END OF TERM III EXAMINATION (ETE III) 2006/2007
COURSE: MSB 103 : BLOOD & IMMUNE MECHANISM
PROGRAMME: M.B.Ch.B. YEAR OF STUDY: 1(ONE)
DATE: 16TH OCTOBER, 2007 TIME: 9.00 A.M. - 12.00 NOON
GENERAL INSTRUCTIONS:-
(i) Write your University Registration Number on every piece of paper you use.
(ii) Do not write your names on any piece of paper you use.
(iii) This paper consists of four (4) sections, headed: Section A - Human Anatomy, Section B - Medical Biochemistry, Section C - Medical Physiology, Section D - Immunology. All to be answered in a total time of three (3) hours.
iv) Each section constitutes a CAT relating to the discipline named.
v) Answer all the questions in all the four (4) sections.
vi) Questions in each section must be answered in separate answer booklets or answer sheets so that they can be handed in separately at the end of the examination.
(iv) Read carefully the additional instructions preceeding each section.
SECTION A: HUMAN ANATOMY
MULTIPLE CHOICE QUESTIONS
TYPE III (20 minutes)
INSTRUCTIONS:-
(I) THERE IS ONLY ONE WRONG STATEMENT IN EACH QUESTION. FIND IT AND MARK X IN THE SHEET PROVIDED.
MCQ TYPE III
1. Concerning bone marrow:
a) The capillaries of the BM are of continuous type.
b) The stroma of BM consists of reticular cells, reticular and collagenous fibers and fibroblasts.
c) The yellow BM is inactive.
d) In adults, red marrow is found only in the vertebrae, ribs, pelvis and proximal ends of the humerus and femur.
e) The yellow BM can revert to the red BM in response to demands for blood cells.
2. Regarding thymus:
a) A blood-thymus barrier is formed by the basal lamina of reticular cells and endothelial cells of the cortical capillaries.
b) Thymosin stimulates proliferation of the T-lymphocytes.
c) The accidental thymic involution is not reversible.
d) Hassall’s corpuscles are located in the medulla.
e) Epithelial reticular cells are stromal components of the thymus.
3. About spleen:
a) Aged erythrocytes cannot pass through the wall of splenic capillaries and are destroyed.
b) Splenic cords of Billroth are situated between the sinusoids.
c) PALS consists of B-lymphocytes.
d) The central artery of the white pulp is subdivided into the penicillar arterioles.
e) Endothelial cells of the sinusoids are enveloped by the transversely arranged reticular fibers.
4. In relation to the lymph nodes:
a) The inner cortex (paracortex) is composed of T-lymphocytes.
b) The germinal centers of secondary nodules are rich in large lymphocytes.
c) The high endothelial venules of the paracortex have no muscular coat.
d) The medullary cords are made up of small lymphocytes, macrophages and plasma cells.
e) Afferent lymphatics enter the hilus of the node.
5. Concerning MALT:
a) The palatine tonsils are separated from the subjacent structures by the capsule composed of dense connective tissue.
b) Lymphoid nodules (follicles) of the lamina propria of GIT and respiratory passages are uncapsulated aggregates of B- and T-lymphocytes.
c) The crypts of tonsils contain live and dead lymphocytes, bacteria and desquamated epithelial cells.
d) The pharyngeal tonsil is covered by the pseudostratified columnar ciliated epithelium.
e) The stratified squamous non keratinized epithelium, covering the palatine tonsils, is infiltrated by the lymphocytes.
6. Regarding development of erythrocytes:
a) Erythropoietin elaborated in kidneys, stimulates process of differentiation of RBC.
b) The first recognizable cell in erythroid series is basophilic erythroblast.
c) The basophilia of the basophilic erythroblast is due to polyribosomes.
d) The cytoplasm of the polychromatophilic erythroblast contains some amount of hemoglobin.
e) Reticulocyte has a small number of polyribosomes.
7. About development of granulocytes:
a) Leucopoietins regulate the process of maturation of granulocytes.
b) The first recognizable cell in the myeloid series is the myeloblast.
c) The first specific granules appear in the cytoplasm at the stage of the promyelocyte.
d) The myelocyte has both azurophilic and specific granules within cytoplasm.
e) The neutrophilic metamyelocyte has rod-like nucleus (band-form).
8. In relation to the development of lymphocytes:
a) CFU-L give rise to the lymphoblasts within the bone marrow.
b) Lymphoblasts and prolymphocytes are transported to the thymus.
c) Activated T-lymphocytes release lymphokines.
d) Stimulated B-lymphocytes differentiate into the plasmablasts, transforming into the plasma cells.
e) B-lymphocytes cannot themselves secrete specific antibodies.
9. Concerning development of platelets:
a) CFU-Me undergo endomitosis, to be transformed into the megakaryocytoblast.
b) Trombopoietin increases number of megakaryocytes in the bone marrow.
c) Megakaryocytoblasts have specific granules within their cytoplasm.
d) Promegakaryocytes send pseudopodia through the wall of sinusoids of the bone marrow.
e) Platelets are formed due to fragmentation of pseudopodia of megakaryocytes within the lumen of sinusoids in the bone marrow.
10. Regarding hemopoiesis:
a) Stem cells of the bone marrow give origin to all blood cells.
b) Pluripotential stem cells proliferate and form two cell lineages: lymphoid multipotential cell and myeloid multipotential cell.
c) CFU form blasts cells under influence of hemopoietins.
d) Precursor cells (blasts) are not capable to mitosis.
e) Growth factor stimulates proliferation of progenitor cells.
SECTION B: MEDICAL BIOCHEMISTRY (35minutes)
SUB-SECTION BI: MULTIPLE CHOICE QUESTIONS (MCQs) (15 minutes)
TYPE III
INSTRUCTIONS:-
(I) EACH OF THE QUESTIONS IN THIS SUBSECTION CONSISTS OF A STATEMENT/QUESTION WHOSE MOST APPROPRIATE COMPLETION/ANSWER IS PROVIDED AMONG THE FIVE OPTIONS NUMBERED (a) - (e).
(II) FOR EACH QUESTION SELECT THE MOST APPROPRIATE OPTION AND INDICATE BY PRINTING AN X IN THE APPROPRIATE BOX IN THE ANSWER SHEETS PROVIDED. IF YOU DO NOT KNOW THE ANSWER, PRINT X IN THE BOX IN THE `DK'' COLUMN
(III) A CORRECT RESPONSE EARNS YOU ONE MARK.
1. Loss of methylene carbon from heme yields
(a) Verdohemoglobin
(b) Hemin
(c) Bilirubin
(d) Urobilin
(e) Stercobilin
2. Which of the following sugars is not a principal sugar in plasma glycoproteins?
(a) Fructose
(b) Glucose
(c) Fucose
(d) Galactose
(e) Mannose
3. Which of the following statements is correct about elastin?
(a) It consists of a triple helix randomly coiled structure
(b) It contains one hydroxylysine residue
(c) It contains a carbohydrate unit
(d) It is especially rich in amino acid lysine
(e) It occurs in only one genetic type
4. Which of the following statements about the Bohr effect is incorrect?
(a) Lowers the pH of blood by increasing acidity of Hb
(b) Affinity of Hb for O2 is diminished by high concentration of CO2
(c) High concentration of O2 promotes the release of CO2 and H+
(d) High concentration of H+ and CO2 allows Hb to be oxygenated
(e) Shifts the O2 dissociation curve of Hb to the right
5. Which of the following is a structural feature of myoglobin?
(a) 75% of amino acids are in ? helices
(b) All the prolines are found within ? helices
(c) The exterior of the molecule consists of nonpolar residues
(d) The interior of the molecule is hollow
(e) The heme group is bound on the surface of the protein
6. Which of the following statement about heme is incorrect?
(a) Its structure has four nitrogen atoms
(b) It is made up of four pyrrole rings
(c) It has four oxygen binding sites
(d) It has four methylene bridges
(e) It has two vinyl groups
7. Which of the following statements about mucin glycoproteins is incorrect?
(a) They are found in secretions of GIT and reproductive tract
(b) They exhibit high content of O-linked oligosaccharides
(c) They contain repeating amino acid sequences of serine, threonine and proline
(d) They form a protective barrier on epithelial surface
(e) They are conjugated to N-acetylglucosamine via serine residue
8. Which of the following statements about Hbs and thalassemias is common to both types of molecular abnormalities?
(a) The defect occurs outside the DNA encoding the protein
(b) The defect result in a stop codon that produces a protein
(c) The defect results in substitution of one amino acid for another
(d) The defect occurs within the structural genes
(e) The defect results from deletion of the gene encoding protein
9. Hb differs from Mb in all of the following except that
(a) Hb is multimetic whereas Mb is monomeric
(b) Hb binds CO2 more effectively than does Mb
(c) The binding of O2 by Hb depends on CO2 and BPG while Mb does not
(d) Hb binds O2 more tightly than does Mb
(e) Hb transports more O2 than does Mb
10. Which of the following class of plasma lipoproteins is formed in the intestine?
(a) LDL
(b) VLDL
(c) Chylomicrons
(d) IDL
(e) HDL
11. Reduction of bilirubin by NADPH is the intestine yields
(a) Urobilinogen
(b) Urobilin
(c) Stercobilin
(d) Biliverdin
(e) Verdoglobin
12. Which of the following statements about collagen is incorrect?
(a) It has a triple helix structure
(b) It lacks hydroxylysine residue
(c) It is a complex molecule containing a carbohydrate
(d) It occurs in many different genetic types
(e) It is especially rich in amino acid glycine and proline
13. Which of the following statements is incorrect? Hbs forms fibrous precipitates
(a) Because valine at position 6 forms a sticky patch on the surface
(b) That are reversible upon oxygenation
(c) That distort the shape of red cells
(d) Only in the deoxy form
(e) Only in hemozygotes
14. The structure of deoxyhemoglobin is stabilized by each of the following interaction except for
(a) BPG binding
(b) Salt bridges between acidic and basic side chains
(c) Coordination of the hemes with distal histidine
(d) Hydrophobic interactions
(e) Salt bridges involving N-terminal carbamates
15. Which of the following class of plasma lipoproteins is not involved in the transport of lipid-based energy?
(a) LDL
(b) HDL
(c) IDL
(d) Chylomicrons
(e) VLDL
SUBSECTION B ii – SHORT ANSWER QUESTIONS (SAQs) (10 minutes each)
INSTRUCTIONS
I) THERE ARE TWO (2) QUESTIONS IN THIS SUBSECTION
II) ANSWER BOTH QUESTIONS
III) START EACH QUESTION ON A FRESH PAGE OF THE BOOKLET.
SAQ 1. Describe the chemical composition and the role of each of the classes of plasma lipoproteins.
SAQ 2. Describe a sequence of reactions leading to the synthesis of heme from glycine.
SECTION C: MEDICAL PHYSIOLOGY(50 Minutes)
SUBSECTION C(i) : MULTIPLE CHOICE QUESTIONS (MCQ) (30 minutes)
TYPE 2
INSTRUCTIONS
(i) EACH OF THE QUESTIONS IN THIS SECTION HAS A STEM STATEMENT FOLLOWED BY FIVE COMPLETIONS NUMBERED (a) TO (e). A GIVEN COMPLETION, WHEN ADDED TO THE STEM STATEMENT MAY PRODUCE A COMPLETE STATEMENT THAT IS TRUE (T) OR FALSE (F).
(ii) INDICATE AGAINST THE APPROPRIATE NUMBERS IN THE ANSWER SHEETS PROVIDED WHETHER THE COMPLETE STATEMENTS IS TRUE (T) OR FALSE (F) BY PRINTING AN X IN THE BOX IN THE COLUMN HEADED T FOR TRUE OR F FOR FALSE.
(iii) IF YOU DO NOT KNOW WHETHER THE COMPLETE STATEMENT IS TRUE OR FALSE, PRINT THE X IN THE COLUMN HEADED D (FOR DO NOT KNOW).
(iv) A CORRECT RESPONSE EARNS YOU PLUS ONE MARK. AN INCORRECT RESPONSE EARNS MINUS ONE - HALF OF A MARK. AN X IN THE D COLUMN EARNS YOU ZERO MARK. ANY UNANSWERED OPTION COUNTS AS INCORRECT.
1. The largest span for active narrow is found in
(a) Ribs
(b) Vertebra
(c) Pelvis
(d) Cranium – mandible
(e) Sternum
2. The largest leucocyte is the
(a) Lymphocyte
(b) Eosinophil
(c) Neutrophil
(d) Monocyte
(e) Basophil
3. Protection against infection in loose connective tissue is offered by
(a) Osteoclasts
(b) Monocytes in the blood
(c) Langerhans’ cells
(d) Histocytes
(e) Microglial cells
4. The following organ has the highest number of macrophages
(a) Kidney
(b) Liver
(c) Lymph node
(d) Brain
(e) Skin
5. Innanimate immunity is offered by
(a) Monocytes
(b) Neutrophils
(c) B-lymphocytes
(d) T-lymphocytes
(e) Natural killer cells
6. Routine neutrophil phagocytosis occurs in
(a) Circulatory system
(b) Respiratory system
(c) Urinary system
(d) Nervous system
(e) None of the above
7. The main function of the Natural Killer Cells is
(a) Release cytokines and growth factors that regulate other immune cells
(b) Immuno-regulation and cytotoxicity
(c) Lysis of virally infected cell and tumor cells
(d) Secretion of antibodies
(e) Activate B-lymphocytes to produce antibodies
8. Contents of Basophilic granules play a role in
(a) Smooth muscle spasms
(b) Myeloperoxidase reactions involving production of hydrogen peroxide
(c) Vaso-dilation of the blood vessels
(d) Enhancement of migration of lymphocyte to the inflamed sites
(e) All of the above
9. Leucoytes that can be found in high numbers in intestinal mucosa, pulmonary mucosa and the skin are
(a) Macrophages
(b) Eosinophils
(c) Neutrophils
(d) Lymphocytes
(e) Basophils
10. Offsprings of a couple where the man is homozygons Rh+ and the woman heterozygous Rh- will be
(a) All will be heterozygous Rh+
(b) 50% will be heterozygous Rh+ and 50% homozygous Rh+
(c) 75% will be homozygous Rh+ and 25% heterozygous Rh+
(d) Homozygous Rh+
(e) All of the above
11. The RBCs of a donor have agglutinagen A and that of the recipient has no agglutinogens. If a transfusion was to be carried out
(a) The donor RBCs will be agglutinated
(b) The recipients RBCs will acquire agglutinogen A from the donor
(c) Both donor’s and recipients RBCs will be agglutinated by agglutinins in their blood
(d) The donor’s RBCs will agglutinate
(e) There will be reaction
12. A Rhesus negative woman married to a Rhesus positive man can be sensitized to produce agglutinins D
(a) By exposure to first child’s blood
(b) If there is damage at the maternal foetal function
(c) If transfused with agglutinin D
(d) By transfusion of blood with agglutinogen D
(e) None of the above
13. Erythroblastosis fetalis may result
(a) Due to compatibility of mother’s and father’s blood
(b) Due to incompatibility of Rh- mother and the Rh+ child
(c) In second pregnancy of Rh- mother married to Rh+ father
(d) Not in compatibility of Rh- and Rh+ child
(e) All of the above
14. Blood treated with an agent to prevent clotting and left to stand in a rack will separate out as follows
(a) Erythrocyte; buff coat; serum
(b) Plasma; buff coat; erythrocyte
(c) Serum, erythrocytes buff coat
(d) Plasma; buff coat; erythrocytes; serum
(e) Platelets; leucocytes; plasma; erythrocytes
15. In erythropoiesis
(a) Erythrogenin is not required
(b) Erythropoetinogen and erythrogenin are required
(c) High levels of steroid hormones are required
(d) High levels of steroid hormones may inhibit the production of red blood cells
(e) None of the above
16. When blood cells are worn out, part of their components are recycled while other are disposed
(a) The greenish pigment, biliverdin, is recycled to the bone marrow
(b) Iton is carried to the bone marrow by a protein called transferring
(c) Biliverdin and bilirubin impart colour bile
(d) Macrophages in the liver and spleen destroy worn out red blood cells
(e) The polypeptide portion of Hb is recycled for production of Hb chains
17. A person with eosinophilia or greater than normal eosinophil, is mostly like not suffering from
(a) Allergies
(b) Parasitic infection
(c) Anaemia
(d) An autoimmune disease
(e) Diabetes
18. The correct order for steps in haemostasis
(a) Blood coagulation, plate plug formation, blood vessels spasms
(b) Platelet plug formation, blood coagulation, blood vessels spasms
(c) Blood vessels spasms, platelet plug formation, blood coagulation
(d) Blood vessel spasms, blood coagulation, platelet plug formation
(e) All of the above
19. Specific ABO blood types
(a) Are known to be linked with increased or decreased susceptibility to particular diseases
(b) Antibodies to alien antigens in the ABO group may be present in one’s body prior to the first contact with blood of a different ABO type
(c) When our blood comes in contact with blood of a different type, our bodies can develop long term immunity to alien blood type
(d) All of the above are correct
(e) All of the bove are not correct
20. The most least likely to be accepted as legal proof of parternity
(a) ABO blood type evidence
(b) HLA type evidence
(c) DNA sequence evidence
(d) All are equally likely to be accepted
(e) Rhesus type evidence
SUBSECTION B(ii): MATCHING QUESTIONS (20 minutes)
TYPE 4
INSTRUCTIONS:
I. THERE IS ONE (1) QUESTION IN THIS SECTION
II. MATCH THE ITEMS IN LIST A WITH THE ITEMS IN LIST B. THE NUMBER OF ITEMS IN LIST B THAT MATCH WITH EACH ITEM IN LIST A INDICATED IN BRACKETS “( )” AFTER EACH LIST A ITEM.
1. LIST I
A. Vasculogenesis (1)
B. Kernictrus (2)
C. 2, 3 – DPF
D. pH
E. Adrogens (1)
F. Oestrogens (1)
LIST II
1. Stimulates erythropoietic response
2. Occurs in newborn with severe jaundice
3. Lowers the pH in the erythrocyte
4. Depress erythropoietic response
5. Causes right shift of oxygen dissociation curve
6. Blood islands and blood vessels
7. Decreases or increases the affinity for oxygen
8. Rare brain damage in new born caused by high levels of bilirubin in the
blood
2. LIST I
A. Polycythaemia (4)
B. Thalassaemia (2)
C. Elliplocytosis (1)
D. Stomato-ovalocytosis (1)
E. Haemoglobinopathies (1)
LIST II
1. Erythrocyte membrane defects that is accompanied by haemolysis of the
RBCs
2. Results in the increased number of circulating erythrocytes
3. Membrane defects of the erythrocytes that are not accompanied by
haemolysis of the erythrocytes
4. Erythrocytes
5. Reduced haemoglobin chains synthesis
6. Abnormal haemoglobin chain synthesis
7. Alpha and beta chains synthesis defects
8. May increase blood volume and reduce rate of venous return
9. Can increase the production of erythropoietin
3. LIST I
A. Megakaryocyte (4)
B. Macrophages (2)
C. Lymphocytes (2)
D. Myoglobin (2)
E. Haemoblobin (1)
LIST II
1. These cells are pre-programmed to respond to specific antigens
2. Serves as a tissue reserve for oxygen
3. The cytoplasm fragments at the edge of the cell to produce cell fragments
4. These cells are most numerous in filter organs
5. The cells are capable of dividing and differentiating into a variety of cell that
protect the body
6. Matures in about 10 days from the blast cells
7. The pre-cursors of this cell store, release iron from lysed erythrocytes
8. Produces the smallest formed elements in the blood
9. Gives the muscles the red colour
10. Defects in the myloid cell may lead to bleeding disorder
11. Transport 90% of O2 to the tissue
4. LIST I
A. T-helper cells (2)
B. CD8+ cells (2)
C. T-lymphocytes
D. CD4+ lymphocytes (2)
E. B-lymphocytes (2)
LIST II
1. Are responsible for cell mediated response
2. Are responsible for humoral response
3. HIV has an affinity for these cells
4. Release cytokines that assist B cells produce antibodies
5. They give rise to cells that produce antibodies
6. In HIV the ratio of these cells decreases
7. Antigenic stimulation cause these cells to proliferate into memory cells
8. Mediate distruction of cell infected with pathogens and are also responsible
for rejection in organ transplant
SECTION D: IMMUNOLOGY
(60 Minutes)
INSTRUCTIONS:-
(i) THIS PAPER IS MADE UP OF TWO (2) SUBSECTIONS: I AND II. SUBSECTION I CONSISTS OF THIRTY (30) MULTIPLE CHOICE QUESTIONS (MCQs) TO BE ANSWERED IN FORTY (40) MINUTES. SUBSECTION II CONSISTS OF TWO (2) SHORT ANSWER QUESTION (SAQs) TO BE ANSWERED IN THIRTY (30) MINUTES.
(ii) FOR THE MCQs, EACH QUESTION CONSISTS OF A STATEMENT/STEM WHOSE MOST CORRECT RESPONSE IS PROVIDED AMONG THE FIVE OPTIONS NUMBERED A TO E.
(iii) FOR EACH MCQ, SELECT ONLY ONE APPROPRIATE OPTION AND INDICATE BY CIRCLING IT.
EXAMPLE:
Major features of innate immunity include
(a) recognition
(b) specificity
(c) memory
d first line of defense
(e) adaptability
The most appropriate response is d
(iv) ATTEMPT ALL QUESTIONS IN THE TWO SUBSECTIONS.
SUBSECTION DI: MULTIPLE CHOICE QUESTIONS (MCQs) (30 minutes)
1. Fc receptors are present on the following cells EXCEPT
(a) Macrophages
(b) Mature dendritic cells
(c) Granulocytes
(d) Immature dendritic cells
(e) Mast cells
2. The basic structure of an antibody consists of
(a) 2H and 2L chains
(b) 1H and 3L chains
(c) 4H and 4L chains
(d) 2H and 1L chains
(e) 3H and 1L chains
3. The effector functions of antibody is determined by
(a) Hypervariable region
(b) Constant region
(c) Variable region
(d) Complementarity-determining region
(e) Hinge region
4. Different isotypes of antibody specificity are determined by
(a) Amino acid sequence within C-region
(b) Amino acid sequence within V-region
(c) Amino acid sequence within hypervariable region
(d) Amino acid sequence within hinge region
(e) Amino acid sequence within variable L-domain
5. IgM and IgG are able to exist as stable multimeric molecular aggregates due to
(a) V-chain
(b) J-chain
(c) I-chain
(d) C-chain
(e) Hypervariable chain
6. All antibody isotypes can be secreted EXCEPT
(a) IgD
(b) IgM
(c) IgA
(d) IgG
(e) IgE
7. The main uses of antibodies in the laboratories are the following EXCEPT
(a) Detection of antigens
(b) Quantitative of antigens
(c) Purification of antigens from complex mixtures
(d) Visualization of antigens in tissues, cells and subcellular compartments
(e) Detection of functional cellular immune responses
8. Immunoglobulin heavy chain genes are located on
(a) Chromosome 6
(b) Chromosome 2
(c) Chromosome 22
(d) Chromosome 14
(e) Chromosome 12
9. B cells produce the following immunoglobulin initially but switch to other isotypes later in the immune response
(a) IgM
(b) IgD
(c) IgG
(d) IgE
(e) IgA
10. Humoral components include the following EXCEPT
(a) T cell and cytokines
(b) Antibodies
(c) Complement system proteins
(d) Memory B cells
(e) IgM, IgG and IgE
11. The following statements are true of complement proteins EXCEPT
(a) C2 and C4 synthesized by macrophages
(b) Are glycoproteins of plasma and cell membranes
(c) Function in conjunction with antibodies
(d) Confer body defence
(e) Do not regulate the immune system
12. In the activation of complement system
(a) C5a, C3a and C2b are not chemotactic factors
(b) C3b and C4b bind into cell surfaces
(c) C4a and C1q diffuse into fluid phase
(d) C3 convertase cleaves C3 in absence of Mg++
(e) C5b C3b, 7 and 8 polymerize to generate membrane attack complex
13. Activators of alternative pathway proteins EXCLUDE
(a) Gram negative bacteria
(b) Heterologous red cells
(c) IgA aggregates
(d) IgG aggregates
(e) Cobra venom factor
14. In mannan binding lectin (MBL) pathway of complement activation the following is NOT the
(a) Mannan-binding lectin binds to microbial mannose groups
(b) Globular head containing carbohydrate recognition domain is equivalent to CIq
(c) Sugars on microorganisms include mannose, L-frucotose and acetylglucosamine
(d) Cleavage of C4, C2 and C3 occurs when CRD binds MBL
(e) MBL associated serine Proteases (MSPs) do not cleave C4, C2 and C3
15. Major biological effects of activated complement system do NOT include
(a) Opsonization and phagocytosis
(b) Vascular permeability
(c) Virus neutralization
(d) Reduce immune recognition
(e) Chemotaxis and inflammation
16. Components of alternative complement pathway include
(a) C1, C4 and C2
(b) Factor D, B and properdin
(c) C3, C4, and C5
(d) C1q, C3b, C4b
(e) Properdin, C1q and factor B (Bf)
17. Major biological function of complement system associated with adaptive immunity is
(a) Neutralization of microbes
(b) MAC mediated lysis of gram-negative bacteria
(c) Increased B cell primary and memory
(d) Immune adherence and phagocytosis of pathogens
(e) Reduced T cell primary and memory
18. Regulators of complement system are as follows EXCEPT
(a) Properdin stabilizes C3b BbP
(b) C1-esterase inhibitor (CIINA) dissociates active C1r and C1s active enzyme sites
(c) Factor 1 dissociates alternative C3 convertase
(d) Decay accelerating factor (DAF) dissociates C3 and C5 convertase
(e) S-protein inhibits C5, 6, 7 and 8 polymerization with C9 (C5b-9)
19. Major opsonins derived from complement proteins include
(a) C5b-9 (MAC)
(b) C5a, C3 and C4b
(c) C1q, C3b and C4b
(d) C3 convertase and C3bBbP
(e) i C3b, C6 and C5b
20. Terminal sequence complement proteins are
(a) C1, inhibitor, Factor H and S-protein
(b) Factor, B, D and properdin
(c) C6, 7, 8 and 9
(d) C1q, Cir and CIs
(e) C2, C3 and C4
21. Immature double negative thymocytes express the following cell markers
(a) TCR, CD3+ and CD4+
(b) CD2, CD7+ and CD3+
(c) TCR, CD3+ and CD8+
(d) CD4+ CD8- and CD3+
(e) CD4- CD8+ and CD3+
22. Intrathymic death of thymocytes in thymus is mediated through
(a) Positive T cell selection
(b) T cell cytotoxicity
(c) Apoptosis
(d) Programmed cell survival
(e) Necrosis
23. The following is true of mature T lymphocytes
(a) Majority express ?? TCR
(b) Are not educated to distinguish self and non self
(c) Seed into primary lymphoid organs
(d) Majority express ?? TCR
(e) Do not acquire TCR
24. TCR is normally co-expressed with the following molecules
(a) CD3
(b) CD4
(c) CD8
(d) DC2
(e) CD7
25. T cell interaction with antigen presenting cells (APC) involve the following adhesion molecules EXCEPT
(a) CD2…………………LFA – 3
(b) LFA-1 ………………1 CAM-1
(c) CD1…………………1CAM-1
(d) CD45R………………CD22
(e) CD28………………..CD80/86
26. Cytotoxicity mechanisms are mediated by the following cells EXCEPT
(a) Cytotoxic T lymphocytes (CTL)
(b) Macrophages
(c) Mast cells
(d) NK cells
(e) Human intestinal intraepithelial lymphocytes (IEL)
27. The following are NOT true of cytotoxic T cells (CTL)
(a) Do not trigger granzymes to destroy viruses
(b) Mediated class I MHC restricted killing of intracellular pathogens
(c) Regulate immune response by producing IFN-?
(d) Co-operate with CD+ T cells through production of IL-2 and IFN-?
(e) Mediate protection against tumours
28. Major macrophage associated functions do NOT include
(a) Antigen processing and presentation
(b) Phagocytosis
(c) Ig secretion
(d) Oxidative respiratory burst
(e) Microbicidal activity
29. Macrophages are activated by CTL through production of
(a) Cytolysins
(b) Lyphotoxins
(c) Gamma-interferon (?-IFN)
(d) Reactive oxygen intermediates
(e) Lysozymes
30. Microbicidal and tumoricidal activity of macrophages is mediated by the following factors EXCEPT
(a) Hydrogen peroxide
(b) Superoxide
(c) Hypochlorous acid
(d) Free chlorine
(e) Lysozymes
31. The following are true of NK cells EXCEPT
(a) Are large granular lymphocyes
(b) Are activated by IL-10
(c) Kill target virus and tumour cells without MHC restriction
(d) K subpopulation mediates ADCC
(e) Distinguish target virus – infected cells from normal ones
32. Cellular immune responses
(a) Mediated by T lymphocytes, macrophage, cytokines and NK cells
(b) Confer protection to extracellular pathogens
(c) Are ineffective against intracellular pathogens
(d) Detected with serological test
(e) Do not mediate graft regulations
33. T cell markers are NOT associated with
(a) ?? TCR (95%) and ?? TCR (5%)
(b) CD1 and CD2
(c) CD45R
(d) CD4 and CD8
(e) CD19 and CD20
34. T cell education and selection process does NOT involve
(a) Negative selection through apoptosis of T cell clones with high affinith for self MHC antigens
(b) Positive selection of T cell clones which recognize foreign antigen with self MHC antigens
(c) Intrathymic death of about 98% by programmed cell death
(d) Education of thymocytes to distinguish between self and non-self components
(e) Antigen stimulation of thymocytes
35. In endogenous antigen processing and presentation
(a) Peptides are generated that associate with class I MHC molecules
(b) Peptides generated associate with class II MHC molecules
(c) Intracellular antigen degradation not mediated by proteosomes
(d) Peptides do not bind MHC class I antigens
(e) Cytotoxic T cells are not activated
36. Mechanisms in T cell activation does NOT involve
(a) MHC – TCR/CD3 – peptides – CD4/CD8 antigen specific signal
(b) Only MHC – TCR/-peptide antigen specific signal
(c) CD40-CD40L coactivation signal
(d) CD80/CD28 costimulatory signal
(e) Interleukin – 1 (IL-1)
37. CD 4 T cells are activated when APCs
(a) Express both class I and II MHC antigens with peptides
(b) Express class II MHC antigens with peptides
(c) Express class I MHC antigen with peptides
(d) Interact with CD8 T cells
(e) Express ICAM with IFA – 1 molecule
38. Regulatory T cells do NOT
(a) Consist of Th1 and Th2 type cells
(b) Control cell mediated responses and inflammation
(c) Express CD80/CD86 cell markers
(d) Provide help to B cells
(e) Inhibit excess antibody production
39. Helper/inducer T cells
(a) Mediate class I MHC restricted killing of targets expressing foreign
antigen
(b) Kill target expressing antigens in association with class II molecules
(c) Do not trigger apoptosis in targets involving granzymes
(d) Are not associated with CD8 T cells
(e) Are associated with CD4 T cells
40. Th1 cytokines consist of
(a) ?-IFN, IL-8, IL-12 and IL-17
(b) IL-4, IL-5, IL-10 and IL-13
(c) IL-1, IL-3, IL-4 and IL-5
(d) IL-5, IL-6, IL-7 and IL-9
(e) ?-IFN, IL-4, IL-6 and IL-17
SUB-SECTION DII - SHORT ANSWER QUESTIONS (SAQs) (20 minutes)
INSTRUCTIONS:
I) THERE ARE TWO (2) QUESTIONS IN THIS SECTION
II) ANSWER THE TWO (2) QUESTIONS
III) START EACH QUESTION ON A FRESH PAGE OF THE BOOKLET OR PAPER.
SAQ 1. (a) Outline the main differences between primary and secondary
immune responses.
(5 minutes)
(b) Briefly describe five (5) functions of sIgA.
(5 minutes)
SAQ 2. (a) Describe the mechanism of complement activation through
alternative pathway.
(5 minutes)
(b) Outline five (5) functions of complement system.
(5 minutes)
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