ATI RN
Immune System Questions Questions
Question 1 of 5
Early studies analyzing the antibody protein fragments generated after proteolytic cleavage revealed important information about the overall structure of the antibody molecule. Which cleavage pattern (indicated by the red triangles in Figure Q4.5) yields a fragment that has the same antigen-binding avidity as the intact antibody, but is unable to activate complement after binding to a pathogen?
Correct Answer: B
Rationale: Assuming Q4.5 shows cleavages, Fab retains binding but lacks Fc for complement; exact pattern inferred.
Question 2 of 5
Which of the following helps activate our nonspecific (innate) defense system?
Correct Answer: B
Rationale: Inflammation is a key innate defense mechanism, activating nonspecific responses to injury or infection, unlike active/passive immunity (adaptive) or erythrocyte mobilization.
Question 3 of 5
The complement system can be activated by
Correct Answer: B
Rationale: Antigen-antibody complexes activate the complement system, enhancing pathogen destruction, not mediators, membranes, or T cells alone.
Question 4 of 5
Which complement pathway becomes activated by spontaneous hydrolysis of C3?
Correct Answer: B
Rationale: The alternative pathway is triggered by spontaneous C3 hydrolysis on pathogen surfaces, unlike classical (antibody-driven) or lectin (sugar-binding) pathways.
Question 5 of 5
Which of the following statements correctly describes the exogenous pathway of antigen processing?
Correct Answer: A
Rationale: The exogenous pathway processes extracellular antigens for MHCII, activating CD4+ T cells, not cytosolic (endogenous) or TAP/proteasome-dependent.