Nokea
Which of the following is NOT a property of CD8+ T cells?
- A. They typically differentiate into cytotoxic T cells (Tc)
- B. They always recognize peptide antigen in association with an MHC molecule
- C. They are important in defense against intracellular pathogens
- D. They are the cell responsible for antibody-dependent cell-mediated cytotoxicity
Correct Answer: D
Rationale: The correct answer is D because CD8+ T cells are not responsible for antibody-dependent cell-mediated cytotoxicity. A is correct as CD8+ T cells differentiate into cytotoxic T cells. B is correct as CD8+ T cells recognize peptide antigens with MHC molecules. C is correct as CD8+ T cells are vital in defense against intracellular pathogens. D is incorrect as CD8+ T cells do not mediate cell cytotoxicity through antibodies.
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A patient with chronic kidney disease has hyperphosphatemia. What is a commonly associated electrolyte imbalance?
- A. Hypokalemia
- B. Hyponatremia
- C. Hypocalcemia
- D. Hypomagnesemia
Correct Answer: C
Rationale: Hyperphosphatemia binds calcium, lowering its availability and causing hypocalcemia in patients with chronic kidney disease.
What is the medical term for an abnormal increase in white blood cells?
- A. Leukocytosis
- B. Thrombocytosis
- C. Anemia
- D. Hemolysis
Correct Answer: A
Rationale: The correct answer is A: Leukocytosis. Leukocytosis refers to an abnormal increase in white blood cells, indicating an immune response. Thrombocytosis (B) is an increase in platelets, not white blood cells. Anemia (C) is a decrease in red blood cells. Hemolysis (D) is the breakdown of red blood cells, not related to an increase in white blood cells. Therefore, A is the correct answer as it specifically relates to an abnormal increase in white blood cells.
Acquired immunity is a result of previous exposure
- A. serious illness
- B. to vaccination
- C. repeated exposure to the same factor
- D. treatment with penicillin
Correct Answer: B
Rationale: The correct answer is B: to vaccination. Acquired immunity is the immune response developed after exposure to a vaccine, which stimulates the immune system to recognize and remember specific pathogens. Vaccination helps the body build immunity without causing serious illness like choice A, without requiring repeated exposure like choice C, and without being related to treatment with penicillin like choice D. Vaccination mimics natural infection, prompting the body to produce memory cells that can respond more effectively when encountering the actual pathogen in the future.
Monoclonal antibodies can be used to:
- A. Block the proliferation of cancer cells
- B. Target cancer cells for destruction
- C. Inhibit inflammatory immune responses
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D because monoclonal antibodies have the ability to block the proliferation of cancer cells by targeting specific antigens on the cancer cells. They can also target cancer cells for destruction through various mechanisms such as antibody-dependent cell-mediated cytotoxicity. Additionally, monoclonal antibodies can inhibit inflammatory immune responses by neutralizing pro-inflammatory mediators or blocking immune cell activation pathways. Therefore, all the options A, B, and C are correct, making D the correct answer.
All of the following are true about antibodies, EXCEPT which one?
- A. They fix complement.
- B. They occur on the surface of B-lymphocyte
- C. They predominate the primary immune response to antigen.
- D. have a single, defined amino acid sequence due to variability.
Correct Answer: D
Rationale: The correct answer is D because antibodies do not have a single, defined amino acid sequence due to variability in their structure. This variability is a result of somatic recombination and hypermutation.
A: Antibodies can fix complement, leading to the destruction of pathogens.
B: Antibodies are produced by B-lymphocytes and can occur on their surface as B-cell receptors.
C: Antibodies predominate the secondary immune response, not the primary response, as memory B-cells are generated during the primary response for a quicker and more robust secondary response.