Chamberlain University
3 MAXE • 242 SOIB
★ ★
C College of Nursing & Health Professions
J O U R N E Y T O E X T R A O R D I N A R Y CO M PA S S I O N AT E C A R E
EST. 1889
BIOS 242 — Examination 3
I M M U N E SYST E M · I N F E C T I O U S D I S E A S E S · M I C R O B I O LO G Y I N H E A LT H C A R E
INSTITUTION Chamberlain University COURSE CODE BIOS 242
PROGRAM Bachelor of Science in Nursing (BSN) ACADEMIC YEAR
EXAM TITLE Examination 3 — Immune System & Infectious Diseases TOTAL QUESTIONS 25 Questions
COURSE TITLE Fundamentals of Microbiology FORMAT Multiple Choice / True-False — Select the Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers the three lines of immune defense, WBC types and functions, antibody classes, T cell subsets, and specific infectious diseases.
▸ All content reflects BIOS 242 learning objectives for immune system and microbial pathogenesis.
▸ Correct answers and detailed rationales appear below each question for exam preparation purposes.
▸ Pay careful attention to antibody functions, T cell roles, and disease-specific causative agents.
SECTION I — IMMUNE SYSTEM, WBCS, ANTIBODIES & INFECTIOUS DISEASES Questions 1 – 25
1. The body's three lines of defense are organized sequentially. Which statement correctly describes them?
A. First line — physical and chemical barriers; Second line — phagocytosis, inflammation, fever, antimicrobial proteins; Third line — B and T cells (specific immunity)
B. First line — B and T cells; Second line — physical barriers; Third line — inflammation
C. First line — antimicrobial proteins; Second line — fever; Third line — skin
D. All three lines respond simultaneously with no sequential order
CORRECT ANSWER A — First line: physical and chemical barriers; Second line: phagocytosis, inflammation, fever, antimicrobial proteins; Third line: B and T cells (specific
immunity)
RATIONALE The immune system is organized into three sequential lines: (1) First line — surface protection composed of anatomical and physiological barriers (skin, mucous
membranes, lysozyme, sweat, pH, resident microbiota); (2) Second line — cellular and chemical systems (phagocytosis, inflammation, fever, antimicrobial
proteins) that respond immediately if pathogens breach surface defenses; (3) Third line — specific host defenses (B cells producing antibodies, T cells mediating
cellular immunity) uniquely developed for each microbe. Physical barriers: hair follicles, sweat glands, mucous membranes. Chemical barriers: lysozyme, saliva,
skin pH, HCl, bile.
2. B cells and T cells mature in different locations. Which statement is correct?
A. B cells mature in the thymus; T cells mature in red bone marrow
B. B cells develop and mature in red bone marrow; T cells develop in bone marrow and mature in the thymus
C. Both B and T cells mature in the lymph nodes
D. B cells mature in the spleen; T cells mature in the liver
CORRECT ANSWER B — B cells develop and mature in red bone marrow; T cells develop in bone marrow and mature in the thymus
RATIONALE B cells (B lymphocytes) develop and mature in red bone marrow — the "B" stands for bone marrow. T cells (T lymphocytes) develop in bone marrow but migrate to
and mature in the thymus — the "T" stands for thymus. This distinction is fundamental to understanding lymphocyte development. Plasma cells (mature B cells)
release antibodies into tissues and blood that attach to antigens for destruction — they can produce up to 2,000 antibodies per second. An antigen (immunogen) is
any foreign molecule (proteins, polysaccharides from cells and viruses) that triggers a specific immune response.
3. White blood cell percentages and functions differ. Which of the following correctly pairs a WBC with its function?
A. Neutrophils (55–90%) — attack and destroy large eukaryotic pathogens; attracted to parasitic infections
B. Eosinophils (2–4%) — produce histamine and heparin; mediate allergic reactions
C. Basophils (<0.5%) — produce histamine and heparin; mediate allergic reactions; share characteristics with mast cells
D. Lymphocytes (20–35%) — contain digestive enzymes in cytoplasmic granules; become macrophages when leaving circulation
CORRECT ANSWER C — Basophils (<0.5%) — produce histamine and heparin; mediate allergic reactions; share characteristics with mast cells
RATIONALE WBC percentages and functions: Neutrophils (55–90%) — produce toxic chemicals, phagocytosis, react early in inflammatory response; a high neutrophil count is a
common sign of bacterial infection. Eosinophils (2–4%) — attack and destroy large eukaryotic pathogens, attracted to parasitic infections (helminths), elevated in
allergies. Basophils (<0.5%) — produce histamine and heparin, mediate allergic reactions, share characteristics with mast cells. Lymphocytes (20–35%) — B cells
form plasma cells producing antibodies; T cells kill foreign cells. Monocytes (3–7%) — released from bone marrow, become macrophages when leaving circulation.
, 4. The three main functional types of T cells and their roles are:
A. Helper T cells — activate macrophages and assist B cells; Regulatory T cells — control T cell response and prevent autoimmunity; Cytotoxic T cells — destroy infected
host cells by secreting perforins and granzymes
B. All T cells perform identical functions of antibody production
C. Helper T cells — produce antibodies; Regulatory T cells — phagocytose bacteria; Cytotoxic T cells — produce histamine
D. T cells only function in the innate immune response, not adaptive immunity
CORRECT ANSWER A — Helper T cells (activate macrophages, assist B cells, help activate cytotoxic T cells); Regulatory T cells (control T cell response, control inflammation,
prevent autoimmunity); Cytotoxic T cells (destroy infected host cells by secreting perforins and granzymes)
RATIONALE The three main T cell types: (1) Helper T cells (CD4) — activate macrophages, assist B cell processes, and help activate cytotoxic T cells. Subsets include Th1
(activates cell-mediated immunity), Th2 (activates macrophages to expel helminths), Th17 (promotes inflammation), Tfh (drives B-cell proliferation),
Treg/CD25/CD4 (controls specific immune responses). (2) Regulatory T cells — control the T cell response, control inflammation, prevent autoimmunity. (3)
Cytotoxic T cells (CD8) — destroy infected host cells and other foreign cells by secreting perforins (form pores) and granzymes (induce apoptosis). Gamma delta T
cells react specifically/nonspecifically to lipid antigens.
5. The five antibody classes differ in their antigen binding sites, placental transfer, and biological functions. Which statement is correct?
A. IgG (2 binding sites) — can cross the placenta; provides long-term immunity and memory antibodies
B. IgA (2 binding sites as monomer, 4 as dimer) — can cross the placenta; primary response antibody
C. IgM (10 binding sites as pentamer) — can cross the placenta; receptor on B cells
D. IgE (2 binding sites) — can cross the placenta; secretory antibody on mucous membranes
CORRECT ANSWER A — IgG (2 binding sites) — can cross the placenta; provides long-term immunity and memory antibodies
RATIONALE IgG (monomer, 2 binding sites) — the ONLY antibody that can cross the placenta; provides long-term immunity and memory antibodies. IgA (monomer, 2 sites;
dimer, 4 sites) — secretory antibody on mucous membranes; CANNOT cross placenta. IgM (pentamer, 10 binding sites) — produced first in response to antigen;
serves as B-cell receptor; CANNOT cross placenta. IgD (monomer, 2 binding sites) — receptor on B cells; CANNOT cross placenta. IgE (monomer, 2 binding sites) —
antibody of allergy and worm infections; CANNOT cross placenta. Only IgG crosses the placenta, providing passive natural immunity to the fetus.
6. Natural and artificial immunity can be active or passive. Which of the following correctly pairs the immunity type with an example?
A. Natural active immunity — vaccination
B. Natural passive immunity — breast milk (IgA antibodies transferred from mother to infant)
C. Artificial active immunity — chicken pox infection
D. Artificial passive immunity — production of one's own antibodies after infection
CORRECT ANSWER B — Natural passive immunity — breast milk (IgA antibodies transferred from mother to infant)
RATIONALE Immunity classifications: (1) Natural active immunity — production of one's own antibodies after natural infection (e.g., chicken pox); (2) Natural passive immunity
— antibodies transferred naturally from mother to child (IgG across placenta prenatally; IgA in breast milk postnatally); (3) Artificial active immunity — vaccination
(purposeful induction of antibody production); (4) Artificial passive immunity — immunotherapy (injection of pre-formed antibodies). Natural immunity is
acquired through normal life experiences. Artificial immunity is produced through medical procedures. The CDC tracks infectious diseases in the US.
7. The four classic signs of inflammation are rubor, calor, tumor, and dolor. Which correctly defines them?
A. Rubor — swelling; Calor — redness; Tumor — pain; Dolor — warmth
B. Rubor — redness (vasodilation); Calor — warmth (increased blood flow); Tumor — swelling (fluid escape); Dolor — pain (nerve stimulation)
C. Rubor — pain; Calor — swelling; Tumor — redness; Dolor — warmth
D. All four terms are synonymous for swelling
CORRECT ANSWER B — Rubor (redness from increased circulation/vasodilation); Calor (warmth from increased blood flow); Tumor (swelling from fluid escaping tissues);
Dolor (pain from stimulation of nerve endings)
RATIONALE The four classic signs of inflammation: Rubor — redness caused by increased circulation and vasodilation in the affected area. Calor — warmth from the increased
flow of blood. Tumor — swelling from increased fluid (exudate) escaping from tissues into the interstitial space. Dolor — pain caused by stimulation of nerve
endings by chemical mediators and pressure. Histamine (a vasoactive mediator produced by mast cells and basophils) causes vasodilation, increased vascular
permeability, and mucus production — its main function is mediating inflammation and allergies. Prostaglandins (produced by most body cells) cause
dilation/constriction of blood vessels and are powerful stimulants of inflammation and pain.
8. The humoral response and cell-mediated immunity target different types of antigens. Which statement correctly distinguishes them?
A. Humoral response — cytotoxic T cells directed at endogenous antigens found within body cells
B. Cell-mediated immunity — B cells producing antibodies against exogenous antigens found outside the body
C. Humoral response — B cells producing antibodies against exogenous antigens; B cells reside in lymph nodes where lymphatic fluid drains
D. Both responses are identical and involve only helper T cells
CORRECT ANSWER C — Humoral response — B cells producing antibodies against exogenous antigens; B cells reside in lymph nodes where lymphatic fluid drains
RATIONALE The humoral response involves B cells producing antibodies in response to exogenous antigens (antigens found outside the body). B cells reside in tissues like
lymph nodes where lymphatic fluid drains, exposing them to pathogens. Cell-mediated immunity involves cytotoxic T cells directed at endogenous antigens
(found within body cells, e.g., viral proteins, cancer cells). Helper T cells participate in BOTH humoral and cell-mediated immunity — their role is to enhance the
response of B cells and cytotoxic T cells to antigens. Most B cells require stimulation from T cells. HIV infects helper T cells (CD4), destroying them and
compromising both responses.
3 MAXE • 242 SOIB
★ ★
C College of Nursing & Health Professions
J O U R N E Y T O E X T R A O R D I N A R Y CO M PA S S I O N AT E C A R E
EST. 1889
BIOS 242 — Examination 3
I M M U N E SYST E M · I N F E C T I O U S D I S E A S E S · M I C R O B I O LO G Y I N H E A LT H C A R E
INSTITUTION Chamberlain University COURSE CODE BIOS 242
PROGRAM Bachelor of Science in Nursing (BSN) ACADEMIC YEAR
EXAM TITLE Examination 3 — Immune System & Infectious Diseases TOTAL QUESTIONS 25 Questions
COURSE TITLE Fundamentals of Microbiology FORMAT Multiple Choice / True-False — Select the Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question unless otherwise instructed.
▸ This examination covers the three lines of immune defense, WBC types and functions, antibody classes, T cell subsets, and specific infectious diseases.
▸ All content reflects BIOS 242 learning objectives for immune system and microbial pathogenesis.
▸ Correct answers and detailed rationales appear below each question for exam preparation purposes.
▸ Pay careful attention to antibody functions, T cell roles, and disease-specific causative agents.
SECTION I — IMMUNE SYSTEM, WBCS, ANTIBODIES & INFECTIOUS DISEASES Questions 1 – 25
1. The body's three lines of defense are organized sequentially. Which statement correctly describes them?
A. First line — physical and chemical barriers; Second line — phagocytosis, inflammation, fever, antimicrobial proteins; Third line — B and T cells (specific immunity)
B. First line — B and T cells; Second line — physical barriers; Third line — inflammation
C. First line — antimicrobial proteins; Second line — fever; Third line — skin
D. All three lines respond simultaneously with no sequential order
CORRECT ANSWER A — First line: physical and chemical barriers; Second line: phagocytosis, inflammation, fever, antimicrobial proteins; Third line: B and T cells (specific
immunity)
RATIONALE The immune system is organized into three sequential lines: (1) First line — surface protection composed of anatomical and physiological barriers (skin, mucous
membranes, lysozyme, sweat, pH, resident microbiota); (2) Second line — cellular and chemical systems (phagocytosis, inflammation, fever, antimicrobial
proteins) that respond immediately if pathogens breach surface defenses; (3) Third line — specific host defenses (B cells producing antibodies, T cells mediating
cellular immunity) uniquely developed for each microbe. Physical barriers: hair follicles, sweat glands, mucous membranes. Chemical barriers: lysozyme, saliva,
skin pH, HCl, bile.
2. B cells and T cells mature in different locations. Which statement is correct?
A. B cells mature in the thymus; T cells mature in red bone marrow
B. B cells develop and mature in red bone marrow; T cells develop in bone marrow and mature in the thymus
C. Both B and T cells mature in the lymph nodes
D. B cells mature in the spleen; T cells mature in the liver
CORRECT ANSWER B — B cells develop and mature in red bone marrow; T cells develop in bone marrow and mature in the thymus
RATIONALE B cells (B lymphocytes) develop and mature in red bone marrow — the "B" stands for bone marrow. T cells (T lymphocytes) develop in bone marrow but migrate to
and mature in the thymus — the "T" stands for thymus. This distinction is fundamental to understanding lymphocyte development. Plasma cells (mature B cells)
release antibodies into tissues and blood that attach to antigens for destruction — they can produce up to 2,000 antibodies per second. An antigen (immunogen) is
any foreign molecule (proteins, polysaccharides from cells and viruses) that triggers a specific immune response.
3. White blood cell percentages and functions differ. Which of the following correctly pairs a WBC with its function?
A. Neutrophils (55–90%) — attack and destroy large eukaryotic pathogens; attracted to parasitic infections
B. Eosinophils (2–4%) — produce histamine and heparin; mediate allergic reactions
C. Basophils (<0.5%) — produce histamine and heparin; mediate allergic reactions; share characteristics with mast cells
D. Lymphocytes (20–35%) — contain digestive enzymes in cytoplasmic granules; become macrophages when leaving circulation
CORRECT ANSWER C — Basophils (<0.5%) — produce histamine and heparin; mediate allergic reactions; share characteristics with mast cells
RATIONALE WBC percentages and functions: Neutrophils (55–90%) — produce toxic chemicals, phagocytosis, react early in inflammatory response; a high neutrophil count is a
common sign of bacterial infection. Eosinophils (2–4%) — attack and destroy large eukaryotic pathogens, attracted to parasitic infections (helminths), elevated in
allergies. Basophils (<0.5%) — produce histamine and heparin, mediate allergic reactions, share characteristics with mast cells. Lymphocytes (20–35%) — B cells
form plasma cells producing antibodies; T cells kill foreign cells. Monocytes (3–7%) — released from bone marrow, become macrophages when leaving circulation.
, 4. The three main functional types of T cells and their roles are:
A. Helper T cells — activate macrophages and assist B cells; Regulatory T cells — control T cell response and prevent autoimmunity; Cytotoxic T cells — destroy infected
host cells by secreting perforins and granzymes
B. All T cells perform identical functions of antibody production
C. Helper T cells — produce antibodies; Regulatory T cells — phagocytose bacteria; Cytotoxic T cells — produce histamine
D. T cells only function in the innate immune response, not adaptive immunity
CORRECT ANSWER A — Helper T cells (activate macrophages, assist B cells, help activate cytotoxic T cells); Regulatory T cells (control T cell response, control inflammation,
prevent autoimmunity); Cytotoxic T cells (destroy infected host cells by secreting perforins and granzymes)
RATIONALE The three main T cell types: (1) Helper T cells (CD4) — activate macrophages, assist B cell processes, and help activate cytotoxic T cells. Subsets include Th1
(activates cell-mediated immunity), Th2 (activates macrophages to expel helminths), Th17 (promotes inflammation), Tfh (drives B-cell proliferation),
Treg/CD25/CD4 (controls specific immune responses). (2) Regulatory T cells — control the T cell response, control inflammation, prevent autoimmunity. (3)
Cytotoxic T cells (CD8) — destroy infected host cells and other foreign cells by secreting perforins (form pores) and granzymes (induce apoptosis). Gamma delta T
cells react specifically/nonspecifically to lipid antigens.
5. The five antibody classes differ in their antigen binding sites, placental transfer, and biological functions. Which statement is correct?
A. IgG (2 binding sites) — can cross the placenta; provides long-term immunity and memory antibodies
B. IgA (2 binding sites as monomer, 4 as dimer) — can cross the placenta; primary response antibody
C. IgM (10 binding sites as pentamer) — can cross the placenta; receptor on B cells
D. IgE (2 binding sites) — can cross the placenta; secretory antibody on mucous membranes
CORRECT ANSWER A — IgG (2 binding sites) — can cross the placenta; provides long-term immunity and memory antibodies
RATIONALE IgG (monomer, 2 binding sites) — the ONLY antibody that can cross the placenta; provides long-term immunity and memory antibodies. IgA (monomer, 2 sites;
dimer, 4 sites) — secretory antibody on mucous membranes; CANNOT cross placenta. IgM (pentamer, 10 binding sites) — produced first in response to antigen;
serves as B-cell receptor; CANNOT cross placenta. IgD (monomer, 2 binding sites) — receptor on B cells; CANNOT cross placenta. IgE (monomer, 2 binding sites) —
antibody of allergy and worm infections; CANNOT cross placenta. Only IgG crosses the placenta, providing passive natural immunity to the fetus.
6. Natural and artificial immunity can be active or passive. Which of the following correctly pairs the immunity type with an example?
A. Natural active immunity — vaccination
B. Natural passive immunity — breast milk (IgA antibodies transferred from mother to infant)
C. Artificial active immunity — chicken pox infection
D. Artificial passive immunity — production of one's own antibodies after infection
CORRECT ANSWER B — Natural passive immunity — breast milk (IgA antibodies transferred from mother to infant)
RATIONALE Immunity classifications: (1) Natural active immunity — production of one's own antibodies after natural infection (e.g., chicken pox); (2) Natural passive immunity
— antibodies transferred naturally from mother to child (IgG across placenta prenatally; IgA in breast milk postnatally); (3) Artificial active immunity — vaccination
(purposeful induction of antibody production); (4) Artificial passive immunity — immunotherapy (injection of pre-formed antibodies). Natural immunity is
acquired through normal life experiences. Artificial immunity is produced through medical procedures. The CDC tracks infectious diseases in the US.
7. The four classic signs of inflammation are rubor, calor, tumor, and dolor. Which correctly defines them?
A. Rubor — swelling; Calor — redness; Tumor — pain; Dolor — warmth
B. Rubor — redness (vasodilation); Calor — warmth (increased blood flow); Tumor — swelling (fluid escape); Dolor — pain (nerve stimulation)
C. Rubor — pain; Calor — swelling; Tumor — redness; Dolor — warmth
D. All four terms are synonymous for swelling
CORRECT ANSWER B — Rubor (redness from increased circulation/vasodilation); Calor (warmth from increased blood flow); Tumor (swelling from fluid escaping tissues);
Dolor (pain from stimulation of nerve endings)
RATIONALE The four classic signs of inflammation: Rubor — redness caused by increased circulation and vasodilation in the affected area. Calor — warmth from the increased
flow of blood. Tumor — swelling from increased fluid (exudate) escaping from tissues into the interstitial space. Dolor — pain caused by stimulation of nerve
endings by chemical mediators and pressure. Histamine (a vasoactive mediator produced by mast cells and basophils) causes vasodilation, increased vascular
permeability, and mucus production — its main function is mediating inflammation and allergies. Prostaglandins (produced by most body cells) cause
dilation/constriction of blood vessels and are powerful stimulants of inflammation and pain.
8. The humoral response and cell-mediated immunity target different types of antigens. Which statement correctly distinguishes them?
A. Humoral response — cytotoxic T cells directed at endogenous antigens found within body cells
B. Cell-mediated immunity — B cells producing antibodies against exogenous antigens found outside the body
C. Humoral response — B cells producing antibodies against exogenous antigens; B cells reside in lymph nodes where lymphatic fluid drains
D. Both responses are identical and involve only helper T cells
CORRECT ANSWER C — Humoral response — B cells producing antibodies against exogenous antigens; B cells reside in lymph nodes where lymphatic fluid drains
RATIONALE The humoral response involves B cells producing antibodies in response to exogenous antigens (antigens found outside the body). B cells reside in tissues like
lymph nodes where lymphatic fluid drains, exposing them to pathogens. Cell-mediated immunity involves cytotoxic T cells directed at endogenous antigens
(found within body cells, e.g., viral proteins, cancer cells). Helper T cells participate in BOTH humoral and cell-mediated immunity — their role is to enhance the
response of B cells and cytotoxic T cells to antigens. Most B cells require stimulation from T cells. HIV infects helper T cells (CD4), destroying them and
compromising both responses.
