MCQ in Immunology: Answers with Explanation

By Acharya Tankeshwar •  Updated: 06/08/22 •  4 min read

This is the collection of some multiple-choice questions to check your understanding of immunology;  definitions, terms, concepts, etc. At the end of these Immunology MCQs, I have posted the answers also. I expect persons who have good exposure to immunology must give correct answers to at least 14 questions, if you failed to do so, please revise immunology once again.

Image source:
  1. Naturally acquired active immunity would be most likely acquired through which of the following processes?
    a. vaccination
    b. drinking colostrum
    c. natural birth
    d. infection with disease-causing organism followed by recovery
  2. Which of the following conveys the longest-lasting immunity to an infectious agent?
    a. Naturally acquired passive immunity
    b. Artificially acquired passive immunity
    c. Naturally acquired active immunity
    d. All of these
    e. None of these
  3. Which of the following substances will not stimulate an immune response unless they are bound to a larger molecule?
    a. Antigen
    b. Virus
    c. Hapten
    d. Miligen
    e. Antibody
  4. B and T cells are produced by stem cells that are formed in:
    a. Bone marrow
    b. The liver
    c. The circulatory system
    d. The spleen
    e. The lymph nodes
  5. B cells mature in the……….. while T cells mature in the
    a. Thymus/bone marrow and gut-associated lymphoid tissue (GALT)
    b. Spleen/bone marrow and GALT
    c. Bone marrow and GALT/thymus
    d. Liver/kidneys
  6. Which of the following immune cells/molecules are most effective at destroying intracellular pathogens?
    a. T helper cells
    b. B cells
    c. Antibodies
    d. Complement
    e. T cytolytic cells
  7. A living microbe with reduced virulence that is used for vaccination is considered:
    a. A toxoid
    b. Dormant
    c. Virulent
    d. Attenuated
    e. Denatured
  8. B cells that produce and release large amounts of antibodies are called:
    a. Memory cells
    b. Basophils
    c. Plasma cells
    d. Killer cells
    e. Neutrophils
  9. The specificity of an antibody is due to
    a. Its valence
    b. The heavy chains
    c. The Fc portion of the molecule
    d. The variable portion of the heavy and light chain
  10. In agglutination reactions, the antigen is a……… and in precipitation reactions, the antigen is a……………
    a. whole-cell/soluble molecule
    b. Soluble molecule/whole-cell
    c. Bacterium/virus
    d. Protein/carbohydrates
    e. Protein/antibody
  11. B Cells are activated by
    a. Complement
    b. Antibody
    c. Interferon
    d. Memory cells
    e. Antigen
  12. Fusion between a plasma cell and a tumor cell creates a
    a. Myeloma
    b. Natural killer cell
    c. Lymphoblast
    d. Lymphoma
    e. Hybridoma
  13. Monoclonal antibodies recognize a single:
    a. Antigen
    b. Bacterium
    c. Epitope
    d. B cell
    e. Virus
  14. Cell-mediated immunity is carried out by………….. while humoral immunity is mainly carried out by………………..
    a. B cells/T cells
    b. Epitopes/antigens
    c. T cells/B cells
    d. Antibodies/antigens
    e. Antibodies/phagocytes
  15. The ability of the immune system to recognize self-antigens versus nonself antigen is an example of:
    a. Specific immunity
    b. Tolerance
    c. Cell-mediated immunity
    d. Antigenic immunity
    e. Humoral immunity

Answers of MCQ Microbiology: Immunology

  1. It’s the easiest MCQ in microbiology. You have to know only the definition of naturally acquired active immunity. Naturally acquired active immunity is produced when the person is exposed to an infectious agent. So the answer is “d”.
  2. Active immunity can last a lifetime or for a period of weeks, months, or years, depending on how long the antibodies persist. So only one option in the choice contains active immunity as a part of the answer. The answer is “c”
  3. Hapten is a small molecule; it can act as an antigen if it binds to a larger protein molecule. So the answer is “c”
  4. This question asked you which stem cell is the immediate precursor of B Cell and T cell. The early development of stem cells takes place in primitive tissue, a late development in the fetal liver, and final development in the bone marrow. So the answer is “a” i.e. bone marrow.
  5. Do you remember the sentence; T cells are thymus-derived cells? If you can remember, you already solved this question. If not you might remember that “differentiation of B Cell takes place in the bone marrow and functional B cells are found in Gut-associated Lymphoid tissue (GALT)”. Yes the right answer is “c”
  6. T cytolytic cell Tc cells and Natural killer cells kill infected host cells which are harboring the intracellular pathogen. So the answer is option “e”
  7. Attenuated means weakened. While making a live attenuated vaccine the virulence of the microorganism is lost but its antigenic characteristics are retained. The answer is “d”.
  8. In this question, the definition is given and the word is asked. The definition of a plasma cell is “B Cell that is capable of producing a large number of antibodies”. So the answer is “c”

I have only posted the answers to the questions from 9-15, if you have any problem understanding those, leave a comment.  I will post the explanations.

9. The variable portion of heavy and light chain

10. Whole-cell/soluble molecule

11. Antigen

12. Hybridoma

13. Epitope

14. T cells/B cells

15. Tolerance

Test your understanding of Immunology. Try our dedicated MCQ Quiz section for Immunology. 

Acharya Tankeshwar

Hello, thank you for visiting my blog. I am Tankeshwar Acharya. Blogging is my passion. As an asst. professor, I am teaching microbiology and immunology to medical and nursing students at PAHS, Nepal. I have been working as a microbiologist at Patan hospital for more than 10 years.

Keep Reading