ATI RN
microbiology chapter 13 test bank Questions
Question 1 of 5
Rotaviruses:
Correct Answer: A
Rationale: The correct answer is A because the NSP4 nonstructural protein of rotaviruses indeed acts in a toxic-like manner by disrupting calcium homeostasis, leading to diarrhea. Choice B is incorrect as rotaviruses can cause significant disease in infants, but not typically in adults. Choice C is incorrect as rotaviruses are resistant to stomach acid. Choice D is incorrect as rotaviruses cause a net secretion of water and loss of ions, contributing to diarrhea.
Question 2 of 5
Laboratory diagnosis of rabies includes all of these except:
Correct Answer: C
Rationale: The correct answer is C: Looking for Ernst-Babes granules. Laboratory diagnosis of rabies typically involves looking for Negri bodies in the brain tissue, intracerebrally infecting mice for virus isolation, and using immunofluorescence method to detect viral antigens. Ernst-Babes granules are not associated with rabies virus and are not used in the diagnosis of rabies. Therefore, choice C is incorrect.
Question 3 of 5
A patient presented with gas gangrene. Gram-positive rods producing spores and gas were isolated from a wound sample. Identify the microorganism.
Correct Answer: A
Rationale: The correct answer is A: Clostridium perfringens. Clostridium perfringens is known to cause gas gangrene and is a Gram-positive rod that produces spores and gas in tissue infections. Clostridium tetani causes tetanus, not gas gangrene. Bacillus anthracis causes anthrax, not gas gangrene. Staphylococcus aureus is a Gram-positive cocci and does not produce spores or gas in the context of gas gangrene. Therefore, based on the characteristics of the microorganism isolated from the wound sample, Clostridium perfringens is the most likely causative agent.
Question 4 of 5
The spores of bacteria can be stained by:
Correct Answer: C
Rationale: The correct answer is C: Method of Moller. This method uses malachite green to stain bacterial spores due to their resistance to decolorization. The other choices, A, B, and D, are incorrect because Romanovski-Gymsa is used for staining blood smears, Ziehl-Nielsen is used for acid-fast bacteria, and Neisser is used for staining Neisseria species, not bacterial spores.
Question 5 of 5
Fungi are free-living _________ organisms:
Correct Answer: C
Rationale: The correct answer is C: heterotrophic. Fungi are heterotrophic organisms that obtain nutrients by absorbing organic compounds from their environment. They do not produce their own food through photosynthesis (option A: autotrophic) or chemosynthesis (option B: chemotrophic). Fungi also do not rely on light for energy (option D: phototrophic). Therefore, the correct choice is C as it accurately describes the nutritional mode of fungi.