Free Immunology MCQs with Answers

• A. Same as epitopes
• B. Carrier required for specific antibody production
• C. High molecular protein
• D. None of the above

Explanation: A hapten is a small, incomplete antigen that can react specifically with antibodies but cannot stimulate antibody production unless…

• A. B lymphocytes
• B. T lymphocytes
• C. Monocytes
• D. Histiocytes

Explanation: The tuberculin reaction is a delayed-type hypersensitivity response mediated mainly by sensitised T lymphocytes, which release cytokines…

• A. Slide flocculation test
• B. Tube flocculation test
• C. Tube agglutination test
• D. Latex agglutination test

Explanation: VDRL detects reagin antibodies by producing visible flocculation on a slide, so it is classified as a slide flocculation test.

• A. T-cells
• B. B-cells
• C. Lymph nodes
• D. Mucosal epithelium

Explanation: The secretory component, also called the secretory piece, is made by mucosal epithelial cells and helps transport IgA across the…

• A. 2 light, 2 heavy chains
• B. 1 heavy, 2 light chains
• C. 1 light, 1 heavy chain
• D. 3 light, 1 heavy chain

Explanation: A basic immunoglobulin molecule contains two identical heavy chains and two identical light chains, linked by disulphide bonds.

• A. Clone
• B. Epitope
• C. Idiotope
• D. Paratope

Explanation: An epitope is the specific part of an antigen recognised by an antibody or immune-cell receptor.

• A. Opsonisation
• B. Chemotaxis
• C. De coding
• D. CFT

Explanation: Opsonisation coats a microbe or antigen with molecules such as IgG or C3b, making it easier for phagocytes to recognise and ingest.

• A. IgG
• B. IgA
• C. IgM
• D. IgD

Explanation: IgM is the first immunoglobulin produced by the fetus and is the earliest antibody made during a primary immune response.

• A. B-Lymphocytes
• B. T-lymphocytes
• C. Monocytes
• D. Leukocytes

Explanation: Graft-versus-host disease occurs when immunocompetent donor T lymphocytes attack the recipient's tissues after transplantation.

• A. IgD
• B. IgE
• C. IgG
• D. IgM

Explanation: IgM is the first antibody produced during a primary immune response because naïve B cells initially secrete it before class switching to…

• A. live vaccine
• B. T.B vaccine
• C. Orally administered
• D. All of the above

Explanation: BCG is a live attenuated vaccine against tuberculosis, but it is administered mainly intradermally rather than orally.

• A. VL domian
• B. CL domian
• C. CH1 domian
• D. CH2 domian

Explanation: Complement binds to the Fc portion of IgG, particularly the CH2 region of its heavy chain.

• A. IgA
• B. IgE
• C. IgM
• D. IgD

Explanation: Secretory immunoglobulin is mainly IgA, which is transported across mucosal epithelium with a secretory component and protects surfaces…

• A. Anaphylactic
• B. Angioneurotic edema
• C. Cell-mediated immunity
• D. Systemic arthus reaction

Explanation: Serum sickness results from circulating antigen-antibody complexes depositing in tissues, making it a systemic type III hypersensitivity…

• A. Macrophages
• B. Plasma cells
• C. T-cells
• D. Neutrophils

Explanation: Plasma cells are terminally differentiated B lymphocytes specialised for secreting large amounts of immunoglobulin.

• A. Hepatitis vaccination
• B. Gamma globulin injection
• C. Immune blood transfusion
• D. Placental transfer of antibodies

Explanation: Placental transfer of maternal IgG gives the fetus temporary protection without the fetus producing the antibodies itself, making it…

• A. Golgi body
• B. Endoplasmic reticulum
• C. Nucleus
• D. Mitochondria

Explanation: Plasma cells synthesize antibody proteins on abundant rough endoplasmic reticulum, while the Golgi apparatus mainly modifies and packages…

• A. IgE
• B. IgM
• C. IgG
• D. IgA

Explanation: IgE binds mast cells and basophils and triggers histamine release during immediate hypersensitivity, including atopy and anaphylaxis.

• A. Heart and the liver
• B. Brain and the meninges
• C. Thymus and the appendix
• D. Spleen and the lymph nodes

Explanation: Antibody-producing B cells and plasma cells are concentrated in secondary lymphoid organs, especially the spleen and lymph nodes.

• A. Lysozyme
• B. Secretozyme
• C. Albumin
• D. Isozyme

Explanation: Lysozyme is an antibacterial enzyme found in egg white and saliva that cleaves peptidoglycan in bacterial cell walls.