ESTUDYR
NATS 1670 MIDTERM #3 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
1. What is a vaccination (best definition)?
A. Injection of antibiotics to treat an active infection
B. Administration of antigenic material (live-attenuated, inactivated, or subunit) to stimulate
active immunity
C. Giving pre-formed antibodies to a person for immediate protection
D. Increasing exposure to germs to cause disease intentionally
Rationale: Vaccination deliberately exposes the immune system to antigens so the body
develops its own adaptive (active) immune response and memory.
2. Which of the following is a common treatment option for allergies?
A. Antibiotics only
B. Immunotherapy, prescription meds (oral/nasal/eye), and allergen avoidance
C. Antiviral injections
D. Surgical removal of the immune system
Rationale: Allergy management includes avoidance, symptomatic medications (antihistamines,
nasal steroids, eye drops) and allergen-specific immunotherapy for long-term desensitization.
3. What is immunotherapy (in the allergy context)?
A. Surgical removal of mast cells
B. Long-term antibiotic use to suppress allergies
C. Emergency epinephrine only
D. Gradual exposure to increasing amounts of allergen to alter immune response
(desensitization)
Rationale: Allergen immunotherapy (subcutaneous or sublingual/oral) aims to shift immune
responses away from allergic pathways, reducing sensitivity over time.
4. Concerning oral immunotherapy (OIT) for food allergy, the safest practice is:
A. Perform OIT at home with friends
B. Start OIT only by reading online guides
C. Conduct OIT under medical supervision (clinic/hospital) because reactions may require
rapid treatment
D. Never use OIT for any food allergy
,ESTUDYR
Rationale: OIT can trigger allergic reactions, so supervised protocols with emergency care access
are recommended.
5. Which method is commonly used for identifying specific allergies?
A. MRI scan of the nose
B. Blood sugar test
C. Skin prick (scratch) test — applying a drop of allergen to the skin and pricking to look for
localized redness/swelling
D. Urine antigen test
Rationale: Skin prick tests are quick, test multiple allergens at once, and show immediate-type
hypersensitivity via wheal-and-flare reactions.
6. What is an advantage of passive immunization (antibody transfer)?
A. Long-term immunity for decades
B. No risk of serum reactions
C. Immediate protection
D. It induces host immune memory
Rationale: Passive immunization delivers pre-formed antibodies that act instantly, but
protection is temporary since the recipient does not make the antibodies.
7. Which of the following is a disadvantage of passive immunization?
A. It guarantees lifelong protection
B. It never causes immune reactions
C. No long-term protection; risk of serum-borne infection and serum sickness in some cases
D. It always induces strong immune memory
Rationale: Passive antibodies wane over time; historically, animal-derived sera caused serum
sickness and posed infection risks before modern screening.
8. Which immune mechanism is described by neutralization?
A. Antibodies cause cell lysis directly
B. Antibodies bind immune cells and destroy them
C. Antibodies bind toxins or viral attachment molecules, preventing them from interacting
with host cells
D. Antibodies precipitate proteins into crystals
Rationale: Neutralization prevents pathogens/toxins from binding to or entering host cells,
blocking their harmful effects.
, ESTUDYR
9. What is agglutination?
A. Dissolving antigens into single molecules
B. Clumping of particles (cells or beads) when multivalent antibodies bind antigens, used in
blood typing and some serologic tests
C. A form of cell lysis by complement only
D. A reaction invisible to laboratory tests
Rationale: Agglutination is visible clumping occurring when antibodies cross-link particulate
antigens (e.g., RBCs, bacteria).
10. What is precipitation in immunology?
A. Formation of gaseous complexes
B. Formation of insoluble antigen–antibody complexes from soluble antigens (may produce
turbidity/precipitate detectable in assays)
C. Only seen in whole blood typing
D. Synonymous with agglutination for cells
Rationale: Precipitation occurs with soluble antigens and antibodies forming lattices; detection
may require lab methods (gel, tube assays).
11. What does opsonization do?
A. Turn antibodies into toxins
B. Prevent immune cells from finding microbes
C. Coat microbes with antibodies (or complement) to enhance recognition and phagocytosis
by macrophages/neutrophils
D. Directly lyse bacterial membranes
Rationale: Opsonins (antibodies/complement fragments) tag microbes for more efficient
ingestion by phagocytes.
12. The lytic attack (complement) pathway results in:
A. Increased antigen presentation only
B. Blocking of phagocytosis forever
C. Formation of membrane attack complexes that create pores in bacterial cell membranes,
causing lysis
D. Production of antibodies from T cells
Rationale: Complement activation can culminate in membrane attack complexes that disrupt
cell membranes, particularly of some bacteria.
NATS 1670 MIDTERM #3 UPDATED EXAM WITH MOST TESTED
QUESTIONS AND ANSWERS | GRADED A+ | ASSURED SUCCESS
WITH DETAILED RATIONALES
1. What is a vaccination (best definition)?
A. Injection of antibiotics to treat an active infection
B. Administration of antigenic material (live-attenuated, inactivated, or subunit) to stimulate
active immunity
C. Giving pre-formed antibodies to a person for immediate protection
D. Increasing exposure to germs to cause disease intentionally
Rationale: Vaccination deliberately exposes the immune system to antigens so the body
develops its own adaptive (active) immune response and memory.
2. Which of the following is a common treatment option for allergies?
A. Antibiotics only
B. Immunotherapy, prescription meds (oral/nasal/eye), and allergen avoidance
C. Antiviral injections
D. Surgical removal of the immune system
Rationale: Allergy management includes avoidance, symptomatic medications (antihistamines,
nasal steroids, eye drops) and allergen-specific immunotherapy for long-term desensitization.
3. What is immunotherapy (in the allergy context)?
A. Surgical removal of mast cells
B. Long-term antibiotic use to suppress allergies
C. Emergency epinephrine only
D. Gradual exposure to increasing amounts of allergen to alter immune response
(desensitization)
Rationale: Allergen immunotherapy (subcutaneous or sublingual/oral) aims to shift immune
responses away from allergic pathways, reducing sensitivity over time.
4. Concerning oral immunotherapy (OIT) for food allergy, the safest practice is:
A. Perform OIT at home with friends
B. Start OIT only by reading online guides
C. Conduct OIT under medical supervision (clinic/hospital) because reactions may require
rapid treatment
D. Never use OIT for any food allergy
,ESTUDYR
Rationale: OIT can trigger allergic reactions, so supervised protocols with emergency care access
are recommended.
5. Which method is commonly used for identifying specific allergies?
A. MRI scan of the nose
B. Blood sugar test
C. Skin prick (scratch) test — applying a drop of allergen to the skin and pricking to look for
localized redness/swelling
D. Urine antigen test
Rationale: Skin prick tests are quick, test multiple allergens at once, and show immediate-type
hypersensitivity via wheal-and-flare reactions.
6. What is an advantage of passive immunization (antibody transfer)?
A. Long-term immunity for decades
B. No risk of serum reactions
C. Immediate protection
D. It induces host immune memory
Rationale: Passive immunization delivers pre-formed antibodies that act instantly, but
protection is temporary since the recipient does not make the antibodies.
7. Which of the following is a disadvantage of passive immunization?
A. It guarantees lifelong protection
B. It never causes immune reactions
C. No long-term protection; risk of serum-borne infection and serum sickness in some cases
D. It always induces strong immune memory
Rationale: Passive antibodies wane over time; historically, animal-derived sera caused serum
sickness and posed infection risks before modern screening.
8. Which immune mechanism is described by neutralization?
A. Antibodies cause cell lysis directly
B. Antibodies bind immune cells and destroy them
C. Antibodies bind toxins or viral attachment molecules, preventing them from interacting
with host cells
D. Antibodies precipitate proteins into crystals
Rationale: Neutralization prevents pathogens/toxins from binding to or entering host cells,
blocking their harmful effects.
, ESTUDYR
9. What is agglutination?
A. Dissolving antigens into single molecules
B. Clumping of particles (cells or beads) when multivalent antibodies bind antigens, used in
blood typing and some serologic tests
C. A form of cell lysis by complement only
D. A reaction invisible to laboratory tests
Rationale: Agglutination is visible clumping occurring when antibodies cross-link particulate
antigens (e.g., RBCs, bacteria).
10. What is precipitation in immunology?
A. Formation of gaseous complexes
B. Formation of insoluble antigen–antibody complexes from soluble antigens (may produce
turbidity/precipitate detectable in assays)
C. Only seen in whole blood typing
D. Synonymous with agglutination for cells
Rationale: Precipitation occurs with soluble antigens and antibodies forming lattices; detection
may require lab methods (gel, tube assays).
11. What does opsonization do?
A. Turn antibodies into toxins
B. Prevent immune cells from finding microbes
C. Coat microbes with antibodies (or complement) to enhance recognition and phagocytosis
by macrophages/neutrophils
D. Directly lyse bacterial membranes
Rationale: Opsonins (antibodies/complement fragments) tag microbes for more efficient
ingestion by phagocytes.
12. The lytic attack (complement) pathway results in:
A. Increased antigen presentation only
B. Blocking of phagocytosis forever
C. Formation of membrane attack complexes that create pores in bacterial cell membranes,
causing lysis
D. Production of antibodies from T cells
Rationale: Complement activation can culminate in membrane attack complexes that disrupt
cell membranes, particularly of some bacteria.
