Nokea
What is the diversity of pattern recognition receptors (PRRs) like?
- A. Highly diverse due to somatic recombination
- B. Limited because they are germline-encoded
- C. Constantly changing in response to infections
- D. Specific to individual antigens
Correct Answer: B
Rationale: The correct answer is B because pattern recognition receptors (PRRs) are encoded in the germline, meaning they are genetically determined and do not change during an individual's lifetime. This ensures consistency in detecting various pathogens across different individuals. Choices A, C, and D are incorrect because PRR diversity is not influenced by somatic recombination, does not change constantly in response to infections, and is not specific to individual antigens.
You may also like to solve these questions
You are evaluating an HIV-positive patient who is receiving IV pentamidine (Pentam) as a treatment for Pneumocystis carinii pneumonia. Which information is most important to communicate to the physician?
- A. The blood pressure decreased to 104/76 during administration.
- B. The patient is complaining of pain at the site of the infusion.
- C. The patient is not taking in an adequate amount of oral fluids.
- D. Blood glucose is 55 mg/dL after the medication administration.
Correct Answer: D
Rationale: Pentamidine can cause hypoglycemia which is a serious and potentially life-threatening side effect. A blood glucose level of 55 mg/dL is critically low and requires immediate intervention. The other findings while important are less urgent and can be managed with standard nursing interventions.
The major role of the complement system is to work in conjunction with
- A. antibodies to lyse cells via the C8 and C9 components
- B. the major histocompatibility complex for cell recognition
- C. antibodies to opsonize cells
- D. the T-cell receptor for production of lymphokines
Correct Answer: A
Rationale: Rationale: The complement system is a group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens. Choice A is correct because the C8 and C9 components of the complement system form the membrane attack complex which lyses cells. Choices B, C, and D are incorrect because the complement system primarily functions independently of the major histocompatibility complex, antibodies for opsonization, and T-cell receptor for lymphokine production.
Polyclonal antibodies made in response to a given antigen will be:
- A. Derived from multiple B cell clones
- B. A mixture of different affinities
- C. A mixture of different antibody classes
- D. All options are correct
Correct Answer: D
Rationale: Step-by-step rationale for why Answer D is correct:
1. Polyclonal antibodies are produced by multiple B cell clones in response to an antigen (Choice A).
2. These antibodies have varying affinities due to the diversity of B cell clones involved (Choice B).
3. Different antibody classes, such as IgM, IgG, IgA, etc., are produced by different B cells (Choice C).
4. Therefore, all options are correct as polyclonal antibodies exhibit these characteristics.
Many immune cells listed below are found in the absence of infection in the lamina propria of the gut with the exception of:
- A. Neutrophils
- B. Macrophages
- C. Plasma cells
- D. T cells
Correct Answer: A
Rationale: Neutrophils are typically not found in the lamina propria of the gut in the absence of infection because they are primarily involved in the acute inflammatory response to infections. Macrophages, plasma cells, and T cells are commonly present in the gut lamina propria to maintain immune homeostasis and respond to antigens. Neutrophils are more abundant in tissues during active infection due to their role in phagocytosis and inflammation. Therefore, the correct answer is A: Neutrophils.
What are the important functions of cell-mediated immunity (select all that apply)?
- A. Fungal infections
- B. Transfusion reactions
- C. Rejection of transplanted tissues
- D. Immunity against pathogens that survive outside cells
Correct Answer: A
Rationale: Cell-mediated immunity targets intracellular pathogens, such as viruses and fungi, and is critical in transplant rejection and certain hypersensitivity reactions.