ATI RN
microbiology an introduction 12th edition test bank Questions
Question 1 of 5
A patient with chronic diarrhea had stool microscopy revealing flagellated protozoa with two nuclei. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Giardia lamblia. Giardia lamblia is a flagellated protozoan with two nuclei found in the stool. It commonly causes chronic diarrhea. The other choices are incorrect because B: Entamoeba histolytica causes dysentery, not chronic diarrhea; C: Trichomonas vaginalis is a sexually transmitted infection, not typically found in stool; D: Balantidium coli is a ciliated protozoan, not flagellated.
Question 2 of 5
Which bacteria are responsible for causing pneumonia?
Correct Answer: D
Rationale: The correct answer is D (All of the above) because different bacteria can cause pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Mycobacterium tuberculosis causes tuberculosis, which can lead to pneumonia. Pseudomonas aeruginosa is a common cause of hospital-acquired pneumonia. Therefore, all three bacteria can be responsible for causing pneumonia in different contexts. Choices A, B, and C are incorrect because each bacterium individually can cause pneumonia, so selecting only one option would not cover the full spectrum of bacterial causes of pneumonia.
Question 3 of 5
Bacteria that have a single polar flagellum at one end are referred to as:
Correct Answer: B
Rationale: Step-by-step rationale: 1. Monotrichous means having a single flagellum at one end. 2. The term "polar" indicates that the flagellum is located at one end of the bacterium. 3. Therefore, bacteria with a single polar flagellum are referred to as monotrichous. 4. Choice A is a typo, as it is the same as the correct answer B. Summary: - Choice A is a typo, as it duplicates the correct answer. - Choice C, amphitrichous, refers to bacteria with a flagellum at each end. - Choice D, peritrichous, describes bacteria with flagella distributed over the entire surface.
Question 4 of 5
Gram-negative rods producing red colonies on Endo agar were isolated from a fecal sample. The bacteria were lactose-fermenting. What microorganism is likely responsible?
Correct Answer: A
Rationale: The correct answer is A: Escherichia coli. E. coli is a Gram-negative rod that ferments lactose, leading to red colonies on Endo agar. This bacterium is commonly found in the human gut and is known for its ability to ferment lactose. Salmonella and Shigella are also Gram-negative rods but do not ferment lactose, so they would not produce red colonies on Endo agar. Proteus is a Gram-negative rod that is not known for its lactose-fermenting ability and would not produce red colonies on Endo agar. Therefore, based on the characteristics provided, E. coli is the most likely microorganism responsible for the red colonies on Endo agar.
Question 5 of 5
Bacteria that use organic compounds as the source of both carbon and energy are referred to as:
Correct Answer: D
Rationale: The correct answer is D: chemoheterotrophs. Chemoheterotrophs use organic compounds as both their carbon source and energy source. They obtain energy by breaking down organic molecules through cellular respiration. Photoautotrophs (A) use light energy to produce organic compounds, chemoautotrophs (B) use inorganic compounds for energy, and photoheterotrophs (C) use light energy but require organic compounds as a carbon source. Therefore, chemoheterotrophs best describe bacteria that obtain both carbon and energy from organic compounds.