BIOS 242 Exam 3 Study Guide:
Immune Defenses Overview
EXAM QUESTIONS AND
VERIFIED CORRECT
ANSWERS LATEST2026-2027
B cells - CORRECT ANSWER-Produce antibodies after activation by helper T cells.
T cells - CORRECT ANSWER-Target infected/cancerous cells. CD4+ (helper), CD8+ (cytotoxic).
Memory cells - CORRECT ANSWER-Enable rapid, stronger responses on future exposure.
Neutrophils - CORRECT ANSWER-Most abundant; first responders; phagocytic; elevated in
bacterial infections.
Eosinophils - CORRECT ANSWER-Combat parasitic worms; involved in allergic responses.
Basophils - CORRECT ANSWER-Circulating cells; release histamine in allergic reactions.
Mast cells - CORRECT ANSWER-Similar to basophils but found in tissues.
, Monocytes - CORRECT ANSWER-Differentiate into macrophages and dendritic cells; potent
phagocytes.
Lymphocytes - CORRECT ANSWER-B cells (humoral immunity), T cells (cell-mediated immunity),
NK cells.
Chemotaxis - CORRECT ANSWER-Movement toward chemical signals from microbes/injured
tissue.
Recognition & Adherence - CORRECT ANSWER-PRRs on phagocytes bind PAMPs (e.g., LPS,
peptidoglycan).
Engulfment - CORRECT ANSWER-Pseudopods surround microbe, forming a phagosome.
Phagosome Formation - CORRECT ANSWER-Internal vesicle that isolates microbe.
Phagolysosome Formation - CORRECT ANSWER-Fusion with lysosome.
Destruction - CORRECT ANSWER-Lysosomal enzymes + ROS (reactive oxygen species) destroy
pathogen.
Exocytosis - CORRECT ANSWER-Residual body released, antigens presented to T cells (MHC II).
Mycobacterium tuberculosis - CORRECT ANSWER-Inhibits phagolysosome fusion.
Capsulated bacteria - CORRECT ANSWER-Resist engulfment.
Immune Defenses Overview
EXAM QUESTIONS AND
VERIFIED CORRECT
ANSWERS LATEST2026-2027
B cells - CORRECT ANSWER-Produce antibodies after activation by helper T cells.
T cells - CORRECT ANSWER-Target infected/cancerous cells. CD4+ (helper), CD8+ (cytotoxic).
Memory cells - CORRECT ANSWER-Enable rapid, stronger responses on future exposure.
Neutrophils - CORRECT ANSWER-Most abundant; first responders; phagocytic; elevated in
bacterial infections.
Eosinophils - CORRECT ANSWER-Combat parasitic worms; involved in allergic responses.
Basophils - CORRECT ANSWER-Circulating cells; release histamine in allergic reactions.
Mast cells - CORRECT ANSWER-Similar to basophils but found in tissues.
, Monocytes - CORRECT ANSWER-Differentiate into macrophages and dendritic cells; potent
phagocytes.
Lymphocytes - CORRECT ANSWER-B cells (humoral immunity), T cells (cell-mediated immunity),
NK cells.
Chemotaxis - CORRECT ANSWER-Movement toward chemical signals from microbes/injured
tissue.
Recognition & Adherence - CORRECT ANSWER-PRRs on phagocytes bind PAMPs (e.g., LPS,
peptidoglycan).
Engulfment - CORRECT ANSWER-Pseudopods surround microbe, forming a phagosome.
Phagosome Formation - CORRECT ANSWER-Internal vesicle that isolates microbe.
Phagolysosome Formation - CORRECT ANSWER-Fusion with lysosome.
Destruction - CORRECT ANSWER-Lysosomal enzymes + ROS (reactive oxygen species) destroy
pathogen.
Exocytosis - CORRECT ANSWER-Residual body released, antigens presented to T cells (MHC II).
Mycobacterium tuberculosis - CORRECT ANSWER-Inhibits phagolysosome fusion.
Capsulated bacteria - CORRECT ANSWER-Resist engulfment.
