Nokea
Mutations in which of the following genes are considered a risk factor for Crohn's disease?
- A. TLR-4
- B. NOD2
- C. NADPH oxidase
- D. IL-2
Correct Answer: B
Rationale: The correct answer is B: NOD2. Mutations in the NOD2 gene have been strongly associated with an increased risk of Crohn's disease. NOD2 is involved in the immune response to bacteria in the gut, and mutations in this gene can lead to dysregulation of the immune system, contributing to the development of Crohn's disease.
A: TLR-4 is involved in the recognition of bacterial components but mutations in this gene are not strongly linked to Crohn's disease.
C: NADPH oxidase is important for the production of reactive oxygen species in immune cells but mutations in this gene are not known to be a risk factor for Crohn's disease.
D: IL-2 is a cytokine involved in immune regulation but mutations in this gene are not associated with an increased risk of Crohn's disease.
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The patient is admitted from home with a stage II pressure ulcer. This wound is classified as a yellow wound using the red-yellow-black concept of wound care. What is the nurse likely to observe when she does her wound assessment?
- A. Serosanguineous drainage
- B. Adherent gray necrotic tissue
- C. Clean, moist granulating tissue
- D. Creamy ivory to yellow-green exudate
Correct Answer: B
Rationale: Yellow wounds typically exhibit adherent gray necrotic tissue, indicating partial-thickness tissue loss without slough or eschar.
Which of the following best describes the relationship between innate and adaptive immunity?
- A. Innate immunity suppresses adaptive immunity
- B. Adaptive immunity enhances innate immune functions
- C. Innate immunity activates and stimulates adaptive immunity
- D. They function entirely independently of each other
Correct Answer: C
Rationale: The correct answer is C because innate immunity plays a crucial role in initiating and influencing adaptive immunity. Innate immunity activates and stimulates adaptive immune responses by recognizing pathogens and initiating the adaptive immune system to produce specific responses. This relationship is essential for the body's overall immune defense.
Choice A is incorrect because innate immunity does not suppress adaptive immunity; instead, they work together synergistically. Choice B is incorrect because adaptive immunity does not enhance innate immune functions, but rather complements them. Choice D is incorrect because innate and adaptive immunity are interconnected and work together to provide comprehensive immune protection.
What are the two phases of Type I hypersensitivity?
- A. Early phase and latent phase
- B. Immediate phase and late phase
- C. Acute phase and chronic phase
- D. Primary phase and secondary phase
Correct Answer: B
Rationale: The correct answer is B: Immediate phase and late phase. In Type I hypersensitivity, the immediate phase occurs rapidly after exposure to an allergen, leading to the release of mediators like histamine. The late phase occurs several hours later, involving sustained inflammatory response.
A: Early phase and latent phase - Incorrect because the terms do not accurately describe the phases of Type I hypersensitivity.
C: Acute phase and chronic phase - Incorrect because Type I hypersensitivity does not typically progress to a chronic phase.
D: Primary phase and secondary phase - Incorrect as these terms are not commonly used to describe the phases of Type I hypersensitivity.
The immunoglobulin Joining chain (J-chain) is
- A. only produced by T-Cells
- B. only produced by neutrophils
- C. associated with only multimeric forms of IgM and IgA
- D. associated with IgE for histamine release
Correct Answer: C
Rationale: Step-by-step rationale:
1. The J-chain is a polypeptide involved in the formation of polymeric IgM and IgA.
2. Polymeric forms of IgM and IgA contain the J-chain, aiding in their multimeric structure.
3. The J-chain is not exclusive to T-cells or neutrophils, making choices A and B incorrect.
4. IgE is associated with FcεRI receptors for histamine release, so choice D is incorrect.
Summary:
The correct answer is C because the J-chain is specifically associated with the multimeric forms of IgM and IgA, helping to form their structure. Choices A, B, and D are incorrect as the J-chain is not solely produced by T-cells, neutrophils, or associated with IgE for histamine release.
Which factor is primarily responsible for the division of bacterial populations into specific zones within sediments?
- A. predation by protozoans
- B. free oxygen availability
- C. competition for suitable electron acceptors
- D. cometabolism of organic compounds
Correct Answer: B
Rationale: The correct answer is B: free oxygen availability. In sediment environments, free oxygen availability plays a crucial role in determining bacterial population distribution due to oxygen gradients. Bacteria that require oxygen will be found in aerobic zones where oxygen is present, while anaerobic bacteria will thrive in zones with limited or no oxygen. This division is primarily responsible for the spatial organization of bacterial populations within sediments.
Choice A: Predation by protozoans is not primarily responsible for division of bacterial populations within sediments as it focuses on interactions between different organisms rather than the environmental factor of oxygen availability.
Choice C: While competition for suitable electron acceptors is important for microbial communities, it is not the primary factor responsible for the division of bacterial populations within sediments.
Choice D: Cometabolism of organic compounds refers to the metabolism of compounds alongside the primary substrate, and it is not directly related to the spatial distribution of bacterial populations within sediments based on oxygen availability.