IMMUNOLOGY AND SEROLOGY LESSON 1 LEC

B

Which scientist observed that milkmaids exposed to cowpox had immunity against smallpox, leading to the development of vaccination?

A. Louis Pasteur

B. Edward Anthony Jenner

C. Elie Metchnikoff

D. Emil von Behring

E. Almroth Wright

D

The term "vaccination" originates from the Latin word "vacca", which translates to:

A. Virus

B. Immunity

C. Smallpox

D. Cow

E. Serum

c

Who is recognized as the "Father of Immunology" for developing live, attenuated vaccines against chicken cholera, anthrax, and rabies?

A. Edward Anthony Jenner

B. Elie Metchnikoff

C. Louis Pasteur

D. Emil von Behring

E. Almroth Wright

c

The process of weakening a microorganism through heating, freezing, chemical treatment, or aging so that it induces immunity without causing disease is known as:

A. Opsonization

B. Diapedesis

C. Attenuation

D. Cross-reactivity

E. Phagocytosis

b

Elie Metchnikoff discovered phagocytosis ("cells that eat cells") by observing motile cells surrounding foreign objects in:

A. Human serum

B. Transparent starfish larvae

C. Cowpox lesions

D. Attenuated chickens

E. Rabbit spinal cords

a

Who demonstrated the birth of humoral immunity by neutralizing diphtheria and tetanus toxins using serum?

A. Emil von Behring

B. Almroth Wright

C. Louis Pasteur

D. Edward Anthony Jenner

E. Elie Metchnikoff

c

Almroth Wright linked cellular and humoral immunity by describing proteins that coat bacteria to make them susceptible to phagocytosis. These proteins are called:

A. Cytokines

B. Epitopes

C. Opsonins

D. Chemokines

E. Granules

d

Which of the following is considered an undesirable consequence of the immune system's function?

A. Natural resistance

B. Recovery from disease

C. Acquired resistance to infections

D. Autoimmune disorder

E. Pathogen eradication

d

Which feature is characteristic of the innate immune system?

A. Requires prior exposure to function

B. Possesses immunologic memory

C. Highly specific for individual antigens

D. Immediate response upon antigen contact

E. Response increases with repeated exposures

c

Which characteristic belongs exclusively to the adaptive immune system?

A. Lacks memory

B. Present normally at birth

C. Memory and high specificity

D. Influenced directly by daily stress and age

E. Does not change with subsequent exposures

d

What percentage of total peripheral blood leukocytes do neutrophils typically represent?

A. 1% – 4%

B. 0% – 1%

C. 20% – 40%

D. 50% – 70%

E. 80% – 90%

b

Primary (azurophilic) granules of neutrophils contain which of the following antimicrobial enzymes?

A. Lactoferrin

B. Myeloperoxidase

C. Collagenase

D. Gelatinase

E. Histamine

e

Secondary (specific) granules of neutrophils contain which chemical or enzyme involved in the oxidative burst pathway?

A. Elastase

B. Cathepsin G

C. Proteinase-3

D. Defensins

E. Lactoferrin

c

The process by which leukocytes squeeze through the endothelial cell walls of capillaries into surrounding tissues is termed:

A. Chemotaxis

B. Opsonization

C. Diapedesis

D. Attenuation

E. Phagocytosis

b

Eosinophils contain eosinophil-specific granules equipped with which major constituent responsible for parasitic destruction?

A. Heparin

B. Major basic protein

C. Histamine

D. Myeloperoxidase

E. Acid phosphatase

c

Which blood leukocyte is normally the least numerous in circulation?

A. Neutrophil

B. Eosinophil

C. Basophil

D. Monocyte

E. Lymphocyte

d

Monocytes are the largest circulating leukocytes; upon migrating into body tissues, they differentiate into:

A. Plasma cells

B. Mast cells

C. Natural killer cells

D. Macrophages

E. Cytotoxic T cells

c

Which tissue cell is considered the most effective antigen-presenting cell (APC) for initiating primary acquired immune responses?

A. Macrophage

B. Mast cell

C. Dendritic cell

D. Plasma cell

E. Neutrophi

b

Specialized dendritic cells found in the skin and mucous membranes are called:

A. Interstitial dendritic cells

B. Langerhans cells

C. Follicular dendritic cells

D. Microglial cells

E. Kupffer cells

e

Which cell surface marker serves as a receptor for complement component C3d on B cells?

A. CD19

B. CD20

C. CD3

D. CD4

E. CD21

a

What surface marker is universally expressed on all mature T lymphocytes as part of their receptor complex?

A. CD3

B. CD19

C. CD20

D. CD56

E. CD16

b

T helper cells are primarily characterized by the cell surface marker:

A. CD8

B. CD4

C. CD19

D. CD21

E. CD56

c

Which T cell subset is primarily responsible for direct killing of virus-infected and tumor cells?

A. T helper cells

B. T regulatory cells

C. T cytotoxic cells (CD8)

D. Plasma cells

E. Follicular T cells

e

Which lymphocyte population possesses the principal cell surface markers CD16 and CD56?

A. B cells

B. T helper cells

C. T cytotoxic cells

D. Plasma cells

E. Natural Killer (NK) cells

b

Natural Killer cells release cytotoxic granules containing serine proteases called:

A. Defensins

B. Granzymes

C. Lysozymes

D. Myeloperoxidases

E. Opsonins

b

Which of the following is classified as a primary lymphatic organ?

A. Spleen

B. Red Bone Marrow

C. Lymph Nodes

D. Tonsils

E. Peyer's patches

a

Approximately what percentage of immature T cells arriving in the thymus successfully graduate to become mature T cells?

A. 2%

B. 10%

C. 25%

D. 50%

E. 98%

c

Immature T lymphocytes differentiate and undergo maturation in which primary lymphoid organ?

A. Red bone marrow

B. Spleen

C. Thymus

D. Lymph node

E. Appendix

c

What is the largest single mass of lymphatic tissue in the human body?

A. Thymus

B. Liver

C. Spleen

D. Appendix

E. Bone marrow

b

In the spleen, blood carries lymphocytes and macrophages that execute immune functions primarily within the:

A. Red pulp

B. White pulp

C. Venous sinuses

D. Splenic cords

E. Subcapsular sinus

b

Unfiltered lymph enters a lymph node through the:

A. Efferent lymphatic vessels

B. Afferent lymphatic vessels

C. Splenic artery

D. High endothelial venules

E. Thoracic duct

c

Within lymph nodes, foreign substances filtered from lymph are trapped by a network of:

A. Elastic fibers

B. Collagen bundles

C. Reticular fibers

D. Fibrin threads

E. Keratin filaments

b

How many palatine tonsils are present in the tonsillar ring of the human pharynx?

A. Single (1)

B. Two (2)

C. Three (3)

D. Four (4)

E. Five (5)

c

Peyer's patches are specialized mucosal-associated lymphoid tissues located within the submucosal layer of the:

A. Stomach

B. Esophagus

C. Intestinal lining (Ileum)

D. Respiratory tract

E. Urinary bladder

c

Within Peyer's patches, specialized epithelial cells that take up small particles, viruses, and bacteria from the lumen are called:

A. Langerhans cells

B. Keratinocytes

C. M cells

D. Plasma cells

E. Interstitial cells

a

Follicles in Peyer's patches are extremely rich in B cells that differentiate into plasma cells producing predominantly which immunoglobulin class?

A. IgA

B. IgD

C. IgE

D. IgG

E. IgM

b

In Cutaneous-Associated Lymphoid Tissue (CALT), outer epidermal cells that express class II MHC molecules and secrete cytokines to induce local inflammation are:

A. Melanocytes

B. Keratinocytes

C. Mast cells

D. Fibroblasts

E. Endothelial cells

d

The phenomenon where exposure to one antigen provides cross-protection against a related pathogen (e.g., cowpox inducing immunity against smallpox) is known as:

A. Attenuation

B. Opsonization

C. Chemotaxis

D. Cross-reactivity

E. Phagocytosi

b

Fully differentiated B lymphocytes dedicated to producing large amounts of antibodies are called:

A. Thymocytes

B. Plasma cells

C. Dendritic cells

D. Natural killer cells

E. Macrophages

a

Which cell marker regulates B-cell development and activation as part of the B-cell coreceptor alongside CD21?

A. CD19

B. CD3

C. CD4

D. CD8

E. CD56

e

Which of the following is NOT a leukocyte from the common myeloid lineage?

A. Neutrophil

B. Eosinophil

C. Basophil

D. Monocyte

E. B lymphocyte

b

Tissue mast cells contain granules packed with heparin, histamine, and protease enzymes. Their lifespan compared to basophils is:

A. Shorter

B. Longer

C. Equal

D. Variable day-to-day

E. Transient

b

Which organ provides hematopoiesis (production of blood cells) during fetal life, stores platelets, and removes old RBCs in adults?

A. Thymus

B. Spleen

C. Lymph node

D. Tonsils

E. Appendix

d

Which non-specific plasma proteins rapidly increase in concentration during acute infection and inflammation?

A. Antibodies

B. Immunoglobulins

C. Opsonins

D. Acute phase reactants

E. Cytokines

c

The single tonsil located in the posterior wall of the nasopharynx is the:

A. Palatine tonsil

B. Lingual tonsil

C. Pharyngeal tonsil

D. Submandibular tonsil

E. Tubal tonsil

c

Mature naive B cells express which two immunoglobulins on their cell membranes?

A. IgG and IgE

B. IgA and IgM

C. IgM and IgD

D. IgG and IgA

E. IgE and IgD

d

Which organ structure is rich in infection-fighting lymphoid cells and helps control bacteria attempting to enter the large intestine?

A. Thymus

B. Spleen

C. Thyroid

D. Appendix

E. Bone marrow

b

Resting/interstitial dendritic cells populating major internal organs such as the heart, liver, lungs, and kidneys are known as:

A. Langerhans cells

B. Interstitial dendritic cells

C. Follicular dendritic cells

D. Kupffer cells

E. Microglia

d

Chemical signals or messengers that attract phagocytes toward the site of infection or tissue damage are involved in:

A. Opsonization

B. Diapedesis

C. Attenuation

D. Chemotaxis

E. Phagocytosis

e

Which surface marker is expressed specifically during B-cell activation and proliferation?

A. CD3

B. CD4

C. CD8

D. CD16

E. CD20

a

Which cell type functions as the principal primary phagocytic responder that arrives first at sites of acute bacterial infection and tissue inflammation?

A. Neutrophil

B. Eosinophil

C. Monocyte

D. Plasma cell

E. Basophil

a

Which circulating granulocyte plays a dominant role in defending the host against multicellular helminthic parasites and participates in allergic inflammatory responses?

A. Eosinophil

B. Macrophage

C. Cytotoxic T cell

D. Natural killer cell

E. B cell

b

Which circulating granulocyte possesses high-affinity IgE receptors and releases histamine during immediate hypersensitivity reactions?

A. Neutrophil

B. Basophil

C. Monocyte

D. Dendritic cell

E. Lymphocyte

b

Circulating monocytes migrate into body tissues where they mature and differentiate into long-lived phagocytic cells termed:

A. Plasma cells

B. Macrophages

C. Natural killer cells

D. Eosinophils

E. Mast cells

c

Which specialized antigen-presenting cells are primarily responsible for capturing, processing, and presenting antigens on MHC molecules to naive T cells to initiate primary adaptive immune responses?

A. Neutrophils

B. Basophils

C. Dendritic cells

D. Erythrocytes

E. Thrombocytes

c

Which innate lymphocyte subset can target and destroy virus-infected cells and tumor cells lacking self-MHC Class I expression without prior sensitization?

A. B lymphocytes

B. T helper lymphocytes

C. Natural Killer (NK) cells

D. Plasma cells

E. Monocytes

d

Which fully differentiated lymphocyte function is dedicated exclusively to the high-rate secretion of soluble immunoglobulin antibodies?

A. Memory cell

B. Dendritic cell

C. Cytotoxic T cell

D. Plasma cell

E. Monocyte

d

Which T cell population interacts specifically with foreign peptide antigens presented on MHC Class II molecules via its CD4 co-receptor?

A. Cytotoxic T cell

B. Natural Killer T cell

C. Gamma-delta T cell

D. Helper T cell

E. Plasma cell

e

Which tissue-bound granulocytic cell resides near epithelial mucosal surfaces and blood vessels, playing a prominent role in IgE-mediated allergic reactions?

A. Neutrophil

B. Eosinophil

C. Monocyte

D. Dendritic cell

E. Mast cell

e

Which cell type recognizes foreign peptides bound to MHC Class I molecules and utilizes perforin and granzymes to induce apoptosis in target cells?

A. B lymphocyte

B. T helper cell

C. Basophil

D. Macrophage

E. Cytotoxic T cell