What is the role of pattern recognition in innate immunity, as proposed by Janeway?

Correct Answer: C

Rationale: Pattern recognition in innate immunity, as proposed by Janeway, involves identifying common pathogen-associated molecular patterns (PAMPs). This is crucial for initiating the immune response against pathogens. PAMPs are specific molecular patterns found on pathogens but not on host cells. By recognizing these patterns, the innate immune system can quickly and effectively identify potential threats and trigger the appropriate immune response. Explanation of why other choices are incorrect: A: Specific recognition of antigens is a function of adaptive immunity, not innate immunity. B: Binding toxins to create immunity is not the primary role of pattern recognition in innate immunity. D: Suppressing lymphocyte activation is not the role of pattern recognition in innate immunity; rather, it is involved in activating immune responses against pathogens.

Correct Answer: C

Rationale: The correct answer is C: 10. Toll-like receptors (TLRs) are a family of proteins involved in the innate immune response. In humans, there are 10 known TLRs that recognize different pathogen-associated molecular patterns. Each TLR is specific to different types of pathogens, allowing for a diverse recognition and response system. Therefore, the correct answer is 10. Choices A, B, and D are incorrect because they do not match the known number of TLRs in humans, which is 10.

Correct Answer: C

Rationale: Answer C is correct because B cell antibody production is part of adaptive immunity, not innate immunity. Innate immunity is the body's first line of defense and includes mechanisms like cytokine secretion, NK cell activity, and phagocytosis by macrophages. B cells are part of the adaptive immune response, producing antibodies specific to pathogens upon exposure. This distinction is crucial in understanding the different roles innate and adaptive immunity play in protecting the body.

Correct Answer: B

Rationale: Perforin released by NK cells forms pores in target cell membranes, allowing for the entry of granzymes which induce target cell death. This process is crucial for the immune response against infected or abnormal cells. Activating B cells (A) is not the role of perforin, as B cells are primarily activated by antigens. Engulfing pathogens (C) is the role of phagocytes like macrophages, not perforin. Inducing inflammation (D) is not directly related to the function of perforin in forming pores in target cell membranes.

Correct Answer: D

Rationale: The correct answer is D: Present at birth. Adaptive immunity is not present at birth; it develops over time in response to exposure to pathogens. A: Adaptive immunity has a slower response compared to innate immunity as it requires activation and proliferation of specific immune cells. B: Adaptive immunity is highly specific in recognizing antigens through antigen receptors on T and B cells. C: Adaptive immunity has memory function, allowing the immune system to "remember" previous encounters with specific pathogens for a faster and stronger response upon re-exposure.