Immunology School Listings Home            

   Immunology Schools Feedback Feedback

Immunology Schools Feedback
ImmunologySchool Listings
Immunology Careers
Free Course on Immunology
Immunology Schools Examination
Immunology Schools FAQs
Anatomy Top Schools/School Rankings
Anatomy Top Schools/School Rankings

MICROBIOLOGY 403: FIRST EXAM KEY

Average score: 76%
Maximum score: 98%
Minimum score: 42%

Approximate scale:
98-92 = A
91-81 = B
80-65 = C
64-56 = D
55-42 = F
Curve
Section I. Quantitative relationships

Questions numbered 1 through 25 count 2 points each (50 points).


B 1. (1) The role of lipopolysaccharide (LPS) in activation of the complement cascade via the classical pathway.
(2)The role of lipopolysaccharide (LPS) in activation of the complement cascade via the alternate pathway.
C 2. (1) The association between a Type II hypersensitivity and the disease known as autoimmune hemolytic anemia.
(2)The association between a Type II hypersensitivity and the disease known as pemphigus.
A 3. (1) The similarities between a T-cell receptor molecule and the Fab (antigen binding domain) fragment of IgG.
(2)The similarities between a T-cell receptor molecule and the Fc (receptor binding domain) fragment of IgG.
A 4. (1) The immunogenicity of a typical exotoxin.
(2)The immunogenicity of a typical endotoxin.
B 5. (1) The communicability of a disease to which 60% of the affected population is immune.
(2)The communicability of a disease to which 20% of the affected population is immune.
A 6. (1) The ability of a B-cell to present antigen to a T-cell.
(2)The ability of a B-cell to present antigen to a macrophage.
A 7. (1) The virulence of an organism with an LD50 of 5 x 103.
(2)The virulence of an organism with an LD50 of 5 x 107.
B 8 (1) The propensity for intracellular pathogens to produce acute disease.
(2)The propensity for intracellular pathogens to produce chronic disease.
B 9. (1) The importance of macrophage activation to the elimination of extracellular bacteria.
(2)The importance of macrophage activation to the elimination of intracellular bacteria.
B 10. (1) The probability that an antigen derived from an extracellular bacterium would be presented to a T-cell via the Class I MHC molecule.
(2)The probability that an antigen derived from an extracellular bacterium would be presented to a T-cell via the Class II MHC molecule.
C 11. (1) The number of Complementarity Determining Regions (CDRs) normally found in an immunoglobulin light chain.
(2)The number of Complementarity Determining Regions (CDRs) normally found in an immunoglobulin heavy chain.
B 12. (1) The role of cytotoxic T-cells in the process known as antibody-dependent cell-mediated cytotoxicity.
(2)The role of K-cells in the process known as antibody-dependent cell-mediated cytotoxicity.
A 13. (1) The probability of finding a CD8 molecule on the surface of a cytotoxic T-cell.
(2)The probability of finding a CD8 molecule on the surface of a helper T-cell.
A 14. (1) The ability of IgG antibody to cross the placenta and help to protect a fetus in utero.
(2)The ability of IgM antibody to cross the placenta and help to protect a fetus in utero.
A 15. (1) The importance of opsonizing antibodies in preventing disease caused by an organism such as Streptococcus pneumoniae whose sole virulence mechanism is the production of a capsule.
(2)The importance of antitoxin antibodies in preventing disease caused by an organism such as Streptococcus pneumoniae whose sole virulence mechanism is the production of a capsule.
B 16. (1) The number of polypeptide chains that make up a molecule of IgG.
(2)The number of polypeptide chains that make up a molecule of IgM.
A 17. (1) The amount of precipitate formed when an antigen-antibody ratio is close to 1:1.
(2)The amount of precipitate formed when an antigen-antibody ratio is close to 1:10.
B 18. (1) The ability of Protein H to inhibit the activation of the complement cascade by cleaving cell membrane bound C3b.
(2)The ability of Factor I to inhibit the activation of the complement cascade by cleaving cell membrane bound C3b.
A 19. (1) The number of structural domains in the alpha chain of a Class I MHC molecule.
(2)The number of structural domains in the alpha chain of a Class II MHC molecule.
A 20. (1) The probability that the idiotypic network hypothesis for regulation of the humoral response occurs when antibody levels are relatively high.
(2)The probability that the idiotypic network hypothesis for regulation of the humoral response occurs when antibody levels are relatively low.
C 21. (1) The ability of the complement complex C3bBbC3b to cleave the component C5.
(2)The ability of the complement complex C4b2b3b to cleave the component C5.
A 22. (1) The role of the thymus in the maturation of T-cells.
(2)The role of the thyroid in the maturation of T-cells.
B 23. (1) The role of the Class II MHC molecule in the recognition of antigen.
(2)The role of the Class II MHC molecule in the presentation of antigen.
A 24. (1) The role of the spleen in collecting blood-borne antigens for contact with immune-responsive cells.
(2)The role of the lymph nodes in collecting blood-borne antigens for contact with immune-responsive cells.
B 25. (1) The time required to observe a reaction resulting from a Type I hypersensitivity.
(2)The time required to observe a reaction resulting from a Type IV hypersensitivity.




Section II. Multiple Choice (2 points each, 26 points total).

Questions 26-29: Correctly match the IMMUNOGLOBULIN on the left with its appropriate CHARACTERISTIC(S) listed on the right.
C26.IgMA.Responsible for allergies
D27.IgGB.Found in secretions
A28.IgEC.Has 10 antigen binding sites
B29.IgAD.Placental transfer
E.Both A and C
F.Both B and D
G.None of the above

Questions 30-34: Correctly match the MOLECULE on the left with its appropriate CELL TYPE(S) listed on the right.
B30.Surface ImmunoglobulinA.T-cells
A31.T-cell ReceptorB.B-cells
G32.Class I MHCC.Macrophages
E33.Class II MHCD.T-cells AND B-cells
E34.Immunoglobulin Fc ReceptorE.B-cells AND Macrophages
F.T-cells AND Macrophages
G.B-cells AND T-cells AND Macrophages
H.None of the above

Questions 35-38: Correctly match the COMPLEMENT COMPONENT listed on the left with its appropriate FUNCTION(S) listed on the right.
C35.C1qA.Polymerizes to form MAC
A36.C9B.Chemotactic factor
B37.C5aC.Antibody recognition protein
D38.Factor BD.Combines with C3b
E.Both A and B
F.Both C and D
G.None of the above




Section III. Short answer (24 points total).

39. (2 points) Give the equation that describes the affinity constant for an antibody-antigen interaction.

[Ab-Ag complex]
Ka = ------------------------
[Ab] x [Ag]




40. (2 points) Draw the “Triangle of Relationships” that I described in class.

     MICROBES
Triangle of relationships Arrow   Arrow
  HUMANS Arrow DRUGS

41. (4 points) Draw the general structure of an IgG immunoglobulin showing i) the Fc region, ii) the antigen binding region, iii) the constant regions and iv) the variable regions.










42. (4 points) Describe the concept of antigen cross-reactivity. Use a picture to illustrate the concept.

Antigen cross-reactivity results when an antibody (Ab1) that is formed in response to a specific antigen (Ag1) is able to bind to a different antigen (Ag2) because of close structural similarities between the two antigens. Ag2 will probably not be bound as tightly as Ag1 (i.e. the Ka for Ag2 is less than the Ka for Ag1). Antigen cross-reactivity forms the basis for several diagnostic tests.






43. (6 points) A researcher studying several new bacterial exotoxins performed the following experiment. A number of mice were divided into 2 groups. The first set of mice were given six different doses of Toxin A and the second group of mice were given six different doses of Toxin B. After 24 hours, the percentage of dead mice was determined and the results are shown in the table.

Dose of Toxin (arbitrary units)
012345
Toxin A0 %3 %10 %50 %90 %100 %
Toxin B0 %30 %75 %95 %100 %100 %

Use these data to 1) draw a graph, 2) determine the LD50 for the two treatments and 3) indicate which of the two treatments had the greatest virulence.

TreatmentLD50
Toxin A3 units
Toxin B1.5 units
Greatest virulenceToxin B

44. (6 points) In the following experiment, three groups of guinea pigs (GP) were employed. On day 1, group 1 guinea pigs received an intravenous injection of bovine serum albumin (BSA) designed to induce IgE. Also on day 1, group 2 guinea pigs received a non-lethal dose of Mycobacterium tuberculosis. Group 3 guinea pigs were given a cookie. After two weeks (day 14), the animals were tested for their responsiveness to BSA and a lethal dose of M. tuberculosis. Complete the following table by indicating whether the guinea pigs in each test group lived (+) or died (-).

Secondary response to:
Primary SensitizationBSAM. tuberculosis
Group 1 GP:BSA--
Group 2 GP:M. tuberculosis++
Group 3 GP:cookie+-

Our Network Of Sites:
Apply 4 Admissions.com               | A2ZColleges.com  | OpenLearningWorld.com  | Totaram.com
Anatomy Colleges.com                 | Anesthesiology Schools.com  | Architecture Colleges.com | Audiology Schools.com
Cardiology Colleges.com            | Computer Science Colleges.com | Computer Science Schools.com | Dermatology Schools.com
Epidemiology Schools.com          | Gastroenterology Schools.com  | Hematology Schools.com     | Immunology Schools.com
IT Colleges.com                | Kinesiology Schools.com  | Language Colleges.com  | Music Colleges.com
Nephrology Schools.com             | Neurology Schools.com  | Neurosurgery Schools.com | Obstetrics Schools.com
Oncology Schools.com    | Ophthalmology Schools.com | Orthopedics Schools.com       | Osteopathy Schools.com
Otolaryngology Schools.com | Pathology Schools.com  | Pediatrics Schools.com   | Physical Therapy Colleges.com
Plastic Surgery Schools.com | Podiatry Schools.com   | Psychiatry Schools.com   | Pulmonary Schools.com 
Radiology Schools.com | Sports Medicine Schools.com | Surgery Schools.com  | Toxicology Schools.com
US Law Colleges.com | US Med Schools.com | US Dental Schools.com

Copyright 2000-2011 Immunology Schools, All Right Reserved. | Site Map | Privacy Policy | Disclaimer