[Campbell Biology P.1023] Based on the text and your understanding of the immune system, if a... | Practice Question

Based on the text and your understanding of the immune system, if a person had a significant macrophage deficiency, which of the following would be the most likely consequence?

  • A: Increased susceptibility to all types of infections due to impaired phagocytosis and antigen presentation.
  • B: Complete loss of adaptive immunity, but innate immunity would remain fully functional.
  • C: An inability to produce antibodies, but cellular immunity would be unaffected.
  • D: Only affects the digestive tract's innate immunity, as stated in the final question of Concept 43.1.

Explanation

Macrophages are critical phagocytic cells that ingest pathogens innate immunity and also act as antigen-presenting cells APCs that initiate adaptive immune responses. A deficiency would therefore severely impair both innate defenses e.g., direct pathogen engulfment and the initiation of adaptive immunity e.g., T-cell activation leading to antibody production and cellular immunity , leading to increased susceptibility to a broad range of infections.