Nokea
What is the central component of the complement system?
- A. C1
- B. C2
- C. C3
- D. C5
Correct Answer: C
Rationale: The correct answer is C: C3. C3 is the central component of the complement system as it plays a crucial role in both the classical and alternative pathways by forming the C3 convertase enzyme. This enzyme initiates the cascade of reactions leading to opsonization, chemotaxis, and cell lysis. Choices A, B, and D are incorrect as C1 is the initiator of the classical pathway, C2 is involved in the formation of the C3 convertase, and C5 is necessary for the formation of the membrane attack complex.
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A pregnant client requires immediate but temporary protection from chickenpox. Which type of immunization would be required?
- A. Naturally acquired active immunization
- B. Artificially acquired active immunization
- C. Passive immunization
- D. Artificially acquired passive immunization
Correct Answer: D
Rationale: Passive immunization provides immediate but temporary protection by introducing pre-formed antibodies which is crucial for a pregnant client who cannot wait for an active immune response.
Which of the following statements about M cells is incorrect?
- A. M cells are found in Peyer's patches in the small intestine
- B. M cells are specialized epithelial cells
- C. M' stands for microfold as these cells show small folds on their luminal side rather than microvilli
- D. They specialize in the transport by transcytosis of IgA from the lamina propria (the tissue immediately below the gut lining) into the intestinal lumen
Correct Answer: D
Rationale: The correct answer is D because M cells do not transport IgA from the lamina propria into the intestinal lumen. Instead, they transport antigens and pathogens from the gut lumen to underlying immune cells. Choice A is correct as M cells are found in Peyer's patches. Choice B is correct as M cells are specialized epithelial cells. Choice C is incorrect as M cells have microfolds on their luminal side, not microvilli.
What chemicals are responsible for the flavor and holes in Swiss cheese?
- A. lactate, oxygen
- B. propionic acid, carbon dioxide
- C. acetic acid, carbon dioxide
- D. ethanol, hydrogen
Correct Answer: B
Rationale: The correct answer is B: propionic acid, carbon dioxide. Propionic acid is produced by bacteria in Swiss cheese, contributing to its nutty flavor. The bacteria also produce carbon dioxide, which forms the characteristic holes. Lactate (A) is a byproduct of bacteria in cheese but not responsible for the flavor or holes. Acetic acid (C) is not commonly found in Swiss cheese. Ethanol (D) and hydrogen are not involved in the flavor or hole formation.
Identify the fluid that is least possible to transmit AIDS.
- A. Blood
- B. Breast milk
- C. Semen
- D. Saliva
Correct Answer: D
Rationale: The correct answer is D: Saliva. Saliva has very low levels of HIV, making it least likely to transmit AIDS. HIV transmission requires direct contact with infected bodily fluids containing high viral loads, such as blood, breast milk, and semen. Saliva does not typically contain enough HIV to transmit the virus, as it has enzymes that can inhibit HIV. Therefore, the risk of HIV transmission through saliva is extremely low compared to the other fluids listed.
A monoclonal antibody called '3F8' was developed to treat neuroblastoma and was subsequently improved by:
- A. Making it more specific for neuroblastoma antigens
- B. Engineering a form that has human rather than mouse variable region protein sequences
- C. Engineering a form that has human rather than mouse constant region protein sequences
- D. Two of these responses are correct
Correct Answer: D
Rationale: The correct answer is D. By engineering a form of the antibody with human variable region protein sequences (choice B), it reduces the risk of immune response in patients. Similarly, by engineering a form with human constant region protein sequences (choice C), it further reduces immunogenicity. Therefore, both B and C contribute to making the antibody more suitable for human use, enhancing its efficacy and safety in treating neuroblastoma. Choices A and D are incorrect as they do not address the crucial aspect of reducing immunogenicity through humanization of the antibody.