Immunology & Serology (Questions) with complete solutions

*From the following, identify a specific component of the adaptive immune system that is formed in response to antigenic stimulation: A. Lysozyme B. Complement C. Commensal organisms D. Immunoglobulin correct answer: *D. Immunoglobulin is a specific part of the adaptive immune system and is formed only in response to a specific antigenic stimulation. Complement, lysozyme, and commensal organisms all act nonspecifically as a part of the adaptive immune system. These three components do not require any type of specific antigenic stimulation. *Which two organs are considered the primary lymphoid organs in which immunocompetent cells originate and mature? A. Thyroid and Peyer's patches B. Thymus and bone marrow C. Spleen and mucosal-associated lymphoid tissue (MALT) D. Lymph nodes and thoracic duct correct answer: *B. The bone marrow and thymus are considered primary lymphoid organs because immunocompetent cells either originate or mature in them. Some immunocompetent cells mature or reside in the bone marrow (the source of all hematopoietic cells) until transported to the thymus, spleen, or Peyer's patches, where they process antigen or manufacture antibody. T lymphocytes, after originating in the bone marrow, travel to the thymus to mature and differentiate.