Innate and Adaptive Immunity: Phagocytosis, PRRs, PAMPs, TLR Signaling, NK Cell Cytotoxicity, Thymocyte Development, TCR Gene Rearrangement, Positive and Negative Selection, cTECs, mTECs, AIRE, Central Tolerance, Clonal Deletion, Clonal Anergy, Clonal Edi

Innate and Adaptive Immunity: Phagocytosis, PRRs, PAMPs, TLR Signaling, NK Cell Cytotoxicity, Thymocyte Development, TCR Gene Rearrangement, Positive and Negative Selection, cTECs, mTECs, AIRE, Central Tolerance, Clonal Deletion, Clonal Anergy, Clonal Editing, αβ and γδ Lineage Commitment, Memory T and B Cells, Somatic Hypermutation, Class Switch Recombination, Germinal Center Dynamics, Affinity Maturation, Plasma Cells, BCR Clustering, Lipid Rafts, T-cell Activation, Costimulation, 2-Signal Hypothesis, Immunological Synapse, Cytokine Signaling, TH1/TH2 Polarization, Cross-Presentation, and Adjuvant-Enhanced Vaccine Responses Exam Questions Verified and Provided with Complete A+ Graded Rationales Latest Updated 2026 1. Which of the following is NOT entirely a response of the innate immune system? A. Phagocytosis by macrophages B. Protection from infection by the skin C. Low pH in the stomach D. Antibody mediated complement activation E. Microbial cell lysis by defensin Answer: D Section: Introduction Difficulty: 2 Hint: What makes antibodies? 2. Which of these characteristics are adaptive? A. Response takes several days to develop B. Responds more quickly upon secondary exposure to pathogens C. Pathogen receptors are extremely varied D. Recognize broad classes of pathogens E. A, B, and C Answer: E Section: Introduction Difficulty: 1 Hint: Review Table 5-1. 3. Which of these characteristics are innate? A. Found in all multicellular plants and animals B. Receptors are encoded in the germline C. Recognize broad classes of pathogens D. Responds more quickly upon secondary exposure to pathogens E. A, B, and C Answer: E Section: Introduction Difficulty: 1 Hint: Review Table 5-1. 4. A mixture of S. aureus and the enteric bacteria E. coli was placed onto the skin of the fingertips of a volunteer. The volunteer immediately touched one of their inoculated fingertips to nutrient agar plate #1 and then waited 30 minutes and touched a different inoculated finger to nutrient agar plate #2. After incubating the plates overnight, what pattern of growth would you expect to see on the plates? A. Both E. coli and S. aureus grew on both plates. B. Plate #1 grew both, while plate #2 grew only S. aureus. C. Plate #1 grew both, while plate #2 grew only E. coli. D. Plate #1 grew only S. aureus, while plate #2 grew both. E. Plate #1 grew only E. coli, while plate #2 grew both. Answer: B Section: Anatomical Barriers to Infection Difficulty: 3 Hint: The skin contains psoriasin, an antibacterial protein. 5. Where would you be LEAST likely to find significant levels of defensins? A. The lung B. The intestine C. The liver D. The skin E. The bladder Answer: C Section: Anatomical Barriers to Infection Difficulty: 2 Hint: Defensins are found in locations where pathogens first contact the host. 6. Which of the following is the CORRECT relationship? _______________ on _____________ recognize _________________ on ____________________. A. PRRs; macrophages; PAMPs; pathogens B. PRRs; pathogens; PAMPs; macrophages C. PAMPs; macrophages; PRRs; pathogens D. PAMPs; neutrophils; PRR; pathogens E. PRRs; macrophages; PAMPs; neutrophils Answer: A Section: Phagocytosis Difficulty: 2 Hint: PRRs are found on antigen-presenting cells. 7. Why are many opsonins multimeric? A. Because they are all derived from the same proto-opsonin B. Because they bind repeating structures on pathogen surfaces C. So that they can be regulated allosterically D. Because they have to crosslink receptors on phagocytes in order for phagocytosis to occur E. Because one subunit binds pathogen and the other has enzymatic activity Answer: B Section: Phagocytosis Difficulty: 2 Hint: M