ATI RN
microbiology test bank Questions
Question 1 of 9
What is the associated disease for rubella virus
Correct Answer: D
Rationale: The correct answer is D: Fifth disease. Rubella virus is associated with Fifth disease, also known as erythema infectiosum. It is caused by parvovirus B19, not rubella virus. Mumps (choice A) is caused by the mumps virus. Roseola (choice B) is caused by human herpesvirus 6 or 7. Rubeola (choice C) is the scientific name for measles, caused by the measles virus. Therefore, the correct answer is Fifth disease as it is the disease associated with rubella virus.
Question 2 of 9
Those organisms which in the process of evolution failed to develop protection from H O can exist 2 2 only in anaerobic conditions. Which of the following enzymes can break hydrogen peroxide down?
Correct Answer: A
Rationale: The correct answer is A: Peroxidase and catalase. Peroxidase and catalase are enzymes that break down hydrogen peroxide into water and oxygen. Peroxidase helps in breaking down low levels of hydrogen peroxide, while catalase is crucial for breaking down high levels of hydrogen peroxide efficiently. This process is important for organisms to prevent damage from reactive oxygen species. Choices B, C, and D are incorrect: B: Oxygenase and hydroxylase are enzymes involved in different biochemical reactions and do not break down hydrogen peroxide. C: Cytochrome oxidase and cytochrome B5 are involved in electron transport chain reactions and not in breaking down hydrogen peroxide. D: Oxygenase and catalase are not correct as oxygenase is not involved in hydrogen peroxide breakdown, only catalase is.
Question 3 of 9
Tularemia is also referred to as:
Correct Answer: D
Rationale: The correct answer is D: rabbit fever. Tularemia is commonly known as rabbit fever due to the fact that it is often contracted through handling infected rabbits or other rodents. This zoonotic disease is caused by the bacterium Francisella tularensis. Scarlet fever (A) is a streptococcal infection characterized by a rash, not related to tularemia. Strep throat (B) is a bacterial infection caused by Streptococcus bacteria and is not associated with tularemia. Cat scratch fever (C) is caused by Bartonella henselae and typically transmitted through cat scratches or bites, not related to tularemia.
Question 4 of 9
Chlorhexidine
Correct Answer: A
Rationale: Step 1: Chlorhexidine belongs to the group of biguanides, making choice A accurate. Step 2: It is commonly used for disinfection of hands, skin, and mucous membranes. Step 3: It has a broad spectrum of antimicrobial activity, making it widely applicable. Summary: Choice B is incorrect as chlorhexidine is not classified as an alcohol. Choice C is incorrect as chlorhexidine has various applications. Choice D is incorrect as chlorhexidine is generally safe for use with low toxicity.
Question 5 of 9
A dimorphic fungus growing as a mold prefers what temperature?
Correct Answer: C
Rationale: The correct answer is C (25°C) because dimorphic fungi typically grow as molds at lower temperatures. At 25°C, the fungus is likely in its mold phase, which is the preferred temperature range for mold growth. Choices A, B, and D are incorrect because 15°C and 20°C are too low for optimal mold growth, and 37°C is too high as it typically favors the yeast phase of dimorphic fungi. Therefore, the preferred temperature for mold growth of a dimorphic fungus is 25°C.
Question 6 of 9
A smear of dental plaque revealed unicellular organisms with pseudopodia and ingested white blood cells. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Entamoeba gingivalis. This organism matches the description provided in the question - unicellular with pseudopodia and ingested white blood cells, commonly found in dental plaque. Entamoeba gingivalis is known to inhabit the oral cavity and is associated with periodontal disease. Trichomonas vaginalis, Giardia lamblia, and Balantidium coli do not match the characteristics mentioned in the question and are not typically found in the oral cavity.
Question 7 of 9
Boiling items in water for __________ minutes will kill most vegetative bacteria and viruses.
Correct Answer: D
Rationale: The correct answer is D (15-Oct) because boiling items for at least 15 minutes is necessary to effectively kill most vegetative bacteria and viruses. This duration ensures that the water reaches a high enough temperature to destroy harmful microorganisms. Choices A, B, and C are incorrect because they do not provide a sufficient amount of time for the water to reach the necessary temperature to effectively kill bacteria and viruses. Shorter durations may not be effective in ensuring food safety.
Question 8 of 9
A 42-year-old patient with gastric ulcer has a disbalance between the aggressive and defensive factors. Which of the following factors contributes to the development of gastric ulcer?
Correct Answer: A
Rationale: The correct answer is A: Helicobacter pylori. This bacterium is a major cause of gastric ulcers by disrupting the balance between aggressive (acid, pepsin) and defensive (mucus, bicarbonate, prostaglandins) factors in the stomach lining. H. pylori infection leads to inflammation, weakening the protective mucosal barrier, making the stomach more susceptible to damage. Choices B, C, and D are defensive factors that help protect the stomach lining and prevent ulcer formation, so they do not contribute to the development of gastric ulcers.
Question 9 of 9
For diphtheria exotoxin is true that:
Correct Answer: C
Rationale: The correct answer is C because diphtheria exotoxin is absorbed into the underlying healthy tissues and spreads throughout the body. This is due to the toxin's ability to enter the bloodstream and target various organs, causing systemic effects. Choice A is incorrect as the toxin does not stay localized at the site of infection. Choice B is incorrect as diphtheria exotoxin does not directly affect neuro-muscular transmission. Choice D is also incorrect as the toxin does spread throughout the body.