Nokea
Which of the following is a feature of antigen recognition by B cells?
- A. Their antigen receptors are never secreted
- B. Their antigen receptors recognize a fragment of protein in combination with an MHC molecule
- C. Their receptors each have two identical antigen binding sites
- D. They recognize pattern associated molecular structures (PAMPs) that are unique to a particular pathogen
Correct Answer: C
Rationale: The correct answer is C because B cell receptors, known as antibodies, are Y-shaped proteins with two identical antigen-binding sites. This feature allows B cells to bind to specific antigens with high specificity. Each B cell receptor can bind to a unique antigen, leading to the initiation of an immune response.
Choice A is incorrect because B cell receptors can be secreted as antibodies to target antigens outside the cell.
Choice B is incorrect because B cell receptors recognize antigens directly, not in combination with MHC molecules.
Choice D is incorrect because B cells primarily recognize specific antigens rather than general PAMPs associated with pathogens.
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Which of the following are not typically found within secondary lymphoid tissues?
- A. naïve lymphocytes
- B. Hematopoietic stem cells
- C. Dendritic cells
- D. Antigen
Correct Answer: B
Rationale: Correct Answer: B - Hematopoietic stem cells are not typically found within secondary lymphoid tissues because they are located in the bone marrow where they give rise to various blood cells. In contrast, secondary lymphoid tissues like lymph nodes and spleen primarily consist of mature immune cells and support immune responses. Naïve lymphocytes (A), dendritic cells (C), and antigens (D) are commonly found in secondary lymphoid tissues as they play crucial roles in the immune response.
NAD and FAD are hydrogen carriers, but cytochromes are electron carriers in bacteria. What happens to the protons (Hâº) in electron transport chains?
- A. They go into solution inside the cytoplasm.
- B. They are taken back by NAD and FAD.
- C. They are carried from cytochromes to oxygen to form water.
- D. They go into solution outside the cytoplasmic membrane.
Correct Answer: D
Rationale: The correct answer is D because in the electron transport chain, protons (H⁺) are pumped across the membrane to create a proton gradient. This gradient is utilized by ATP synthase to produce ATP. Therefore, protons go into solution outside the cytoplasmic membrane. Choices A and B are incorrect because protons do not simply stay in the cytoplasm or get taken back by NAD and FAD. Choice C is incorrect as protons do not directly form water when carried by cytochromes.
Which of the following correctly explains an epitope?
- A. Region of antibody that binds with antigen
- B. Region of antigen that elicit secretion of specific antibody
- C. Heavy chain of an antibody
- D. V-region of the light chain of antibody
Correct Answer: B
Rationale: Explanation:
An epitope is a specific region on an antigen that elicits the immune response and triggers the production of a specific antibody. Therefore, choice B is correct as it accurately defines an epitope. Choices A, C, and D are incorrect because they do not accurately describe what an epitope is. Choice A refers to the paratope, the region of the antibody that binds to the epitope. Choice C refers to a component of the antibody structure, and choice D refers to a specific region of the antibody structure.
Which characteristics are seen with acute transplant rejection (select all that apply)?
- A. Treatment is supportive
- B. Only occurs with transplanted kidneys
- C. Organ must be removed when it occurs
- D. The recipient’s T cytotoxic lymphocytes attack the foreign organ
Correct Answer: D
Rationale: Acute transplant rejection involves the recipient's T cytotoxic lymphocytes attacking the transplanted organ, requiring immunosuppressive therapy.
When the patient asks about the late effects of chemotherapy and high-dose radiation, what areas of teaching should the nurse plan to include when describing these effects?
- A. Third space syndrome
- B. Secondary malignancies
- C. Chronic nausea and vomiting
- D. Persistent myelosuppression
Correct Answer: B
Rationale: Late effects of chemotherapy and radiation include secondary malignancies due to long-term cellular damage.