Which of the following is NOT true? The meeting of naïve T cells and dendritic cells:
- A. Is facilitated by the presence of naïve B cells
- B. Occurs in the paracortex of lymph nodes
- C. Is facilitated by movement of the T cell along connective tissue networks
- D. May supply the T cell with activation Signal 1
Correct Answer: A
Rationale: The correct answer is A because the meeting of naïve T cells and dendritic cells is not facilitated by the presence of naïve B cells. Naïve T cells interact with dendritic cells in the paracortex of lymph nodes, not with naïve B cells. The movement of T cells along connective tissue networks aids in their interaction with dendritic cells, and this interaction may supply the T cell with activation Signal 1, which is essential for T cell activation. Overall, the incorrect choices (B, C, and D) are actually true statements regarding the meeting of naïve T cells and dendritic cells, making them incorrect options.
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Which of the following concerned with Leishmania is NOT true
- A. Meditated by IgE
- B. Is a unicellular parasite
- C. Activation of macrophages is essential for killing the parasite
- D. Escapes host immune attack by hiding inside neutrophils
Correct Answer: a
Rationale: The correct answer is A: Mediated by IgE. Leishmania infection is not primarily mediated by IgE antibodies. The immune response against Leishmania involves T cells, macrophages, and cytokines. IgE is not a major player in the defense against Leishmania. Choices B, C, and D are incorrect because Leishmania is indeed a unicellular parasite, activation of macrophages is essential for killing the parasite, and Leishmania can hide inside neutrophils to escape the host immune attack.
Which is not a PAMP?
- A. Viral dsRNA
- B. Peptidoglycan
- C. ROS
- D. Flagellin
Correct Answer: C
Rationale: The correct answer is C: ROS (Reactive Oxygen Species) is not a PAMP (Pathogen-Associated Molecular Pattern) because it is not a specific molecular pattern derived from pathogens. PAMPs are recognized by the innate immune system to trigger an immune response. Viral dsRNA, peptidoglycan, and flagellin are all examples of PAMPs as they are specific molecules commonly found in pathogens that can be recognized by pattern recognition receptors (PRRs) on immune cells, leading to activation of the immune response.ROS, on the other hand, are reactive molecules produced by host cells in response to pathogens but are not specific molecular patterns derived from pathogens. Therefore, ROS is not considered a PAMP.
Which of the following cytokines is NOT included in the interleukin family?
- A. IL-1
- B. IL-22
- C. IFN-alpha
- D. IL-10
Correct Answer: C
Rationale: The correct answer is C: IFN-alpha. This is because IFN-alpha belongs to the interferon family, not the interleukin family. Interleukins are a subset of cytokines that are primarily involved in regulating immune responses, while interferons have antiviral properties. IL-1, IL-22, and IL-10 are all interleukins and are part of the interleukin family. Therefore, IFN-alpha is the only cytokine listed that is not included in the interleukin family.
Which antibody dominates the primary immune response?
- A. IgG
- B. IgA
- C. IgM
- D. IgE
Correct Answer: C
Rationale: The correct answer is C: IgM. During the primary immune response, IgM is the first antibody produced by the immune system in response to an antigen. IgM is efficient in agglutination and complement fixation, aiding in the elimination of pathogens. IgG is more prominent in the secondary immune response. IgA is mainly found in mucosal areas. IgE is associated with allergic reactions and parasitic infections, not the primary immune response. So, IgM dominates the primary immune response by being the initial antibody produced to combat antigens.
What statement accurately describes gene therapy?
- A. May activate a mutated gene that is functioning improperly.
- B. Is a risky technique under study for genetic diseases with no cure.
- C. Is frequently done by replacing a healthy gene with a mutated gene.
- D. Introduces a new gene into reproductive cells to help fight a genetic disease.
Correct Answer: B
Rationale: Gene therapy remains experimental and involves risks, aiming to treat genetic diseases by altering or replacing defective genes.