ATI RN
microbiology an evolving science test bank Questions
Question 1 of 5
Which of the following bacteria produces a toxin that inhibits protein synthesis?
Correct Answer: A
Rationale: Rationale: Shigella dysenteriae produces Shiga toxin, which inhibits protein synthesis by inactivating the 60S ribosomal subunit. This disrupts the translation process, leading to cell death. Escherichia coli (choice B) does not produce a toxin that inhibits protein synthesis. Clostridium tetani (choice C) produces tetanospasmin, which affects the nervous system. Staphylococcus aureus (choice D) produces toxins that cause food poisoning but do not inhibit protein synthesis.
Question 2 of 5
Patients after transplantation of allogeneic stem cells are monitored periodically for reactivation of
Correct Answer: B
Rationale: The correct answer is B: CMV. Patients after allogeneic stem cell transplantation are monitored for CMV reactivation due to its potential to cause severe complications in immunocompromised individuals. CMV can lead to organ damage and even mortality in these patients. Monitoring for CMV reactivation allows for early detection and prompt intervention. Incorrect Choices: A: HAV - Hepatitis A virus reactivation is not commonly monitored in post-transplant patients. C: Rubella virus - Rubella is not a common concern for reactivation in this patient population. D: Measles virus - Measles reactivation is not typically monitored in these patients.
Question 3 of 5
Natural active immunity occurs during infection or disease. It is active because lymphocytes are activated by antigens or pathogen's surface
Correct Answer: A
Rationale: Rationale: Natural active immunity is indeed active because it involves the activation of lymphocytes by antigens during infection or disease. This process leads to the production of memory cells for long-lasting protection. This distinguishes it from passive immunity, where antibodies are transferred rather than produced by the individual's immune system. Therefore, choice A is correct. Choice B is incorrect because it contradicts the nature of natural active immunity. Choice C is incorrect as the statement is always true for natural active immunity. Choice D is incorrect as there is a correct answer among the given choices.
Question 4 of 5
The relations between the macroorganism and the resident skin microflora are defined as:
Correct Answer: A
Rationale: The correct answer is A: Commensalism. In this relationship, the skin microflora benefits from the host without causing harm or benefitting it. This is evident in the mutualistic interaction where the microflora receive nutrients and a place to live, while the host remains unaffected. Choice B, Infection, is incorrect because it implies harm to the host. Choice C, Parasitism, is also incorrect as it involves one organism benefiting at the expense of the other. Choice D, No correct answer, is not applicable here as Commensalism accurately describes the relationship between the macroorganism and skin microflora.
Question 5 of 5
Which one is an example of an immunomodulator:
Correct Answer: B
Rationale: Step-by-step rationale for why B (Gamma Interferon) is the correct answer: 1. Gamma Interferon is a type of immunomodulator that helps regulate the immune response. 2. It activates macrophages and enhances the immune system's ability to fight infections. 3. Rifampin is an antibiotic, not an immunomodulator. 4. Hexacima and Pentaxim are combination vaccines, not immunomodulators. In summary, Gamma Interferon is the correct answer as it directly influences the immune response, while the other choices are not immunomodulators.