OpenStax Microbiology Test Bank

Questions 82

ATI RN

ATI RN Test Bank

OpenStax Microbiology Test Bank Questions

Question 1 of 5

A dentist has detected symptoms of parodontosis in a patient. What antiprotozoal drug should be prescribed?

Correct Answer: A

Rationale: The correct answer is A: Metronidazole. Parodontosis is a condition caused by bacterial infection, not protozoal infection. Metronidazole is an effective antibiotic commonly used to treat bacterial infections in the oral cavity, including those associated with parodontosis. Levamisole is an anthelmintic drug used to treat parasitic worm infections, not suitable for parodontosis. Griseofulvin is an antifungal medication used for fungal infections, not indicated for parodontosis. Mykoseptin is not a recognized drug and is likely a distractor. Therefore, based on the bacterial nature of parodontosis, Metronidazole is the appropriate choice.

Question 2 of 5

Spheroplasts are bacteria with defective cell walls which:

Correct Answer: A

Rationale: The correct answer is A because spheroplasts are bacteria with defective cell walls that have a parietal layer (peptidoglycan layer) and a defective peptidoglycan layer. This is because spheroplasts have lost their rigid cell wall structure, leading to an incomplete peptidoglycan layer. Choice B is incorrect as the cytoplasmic membrane is not directly affected by the loss of cell wall integrity. Choice C is incorrect because spheroplasts do not have an outer membrane defect, but rather a defect in the peptidoglycan layer. Choice D is incorrect because spheroplasts still have peptidoglycan, even though it is defective.

Question 3 of 5

Which bacteria are Gram-negative cocci?

Correct Answer: A

Rationale: The correct answer is A: Neisseria species. Gram staining differentiates bacteria based on cell wall composition. Gram-negative bacteria like Neisseria have a thin peptidoglycan layer and an outer membrane, making them appear pink under the microscope. Streptococcus species (B) are Gram-positive cocci with a thick peptidoglycan layer, appearing purple. Bacillus (C) and Clostridium (D) species are Gram-positive rods, not Gram-negative cocci. Thus, the correct answer is A because Neisseria species are the only Gram-negative cocci among the choices provided.

Question 4 of 5

What is the main component of bacterial cell walls?

Correct Answer: C

Rationale: The correct answer is C: Peptidoglycan. Bacterial cell walls are primarily composed of peptidoglycan, a unique molecule consisting of alternating sugar chains connected by peptide cross-links. This structure provides rigidity and shape to the cell wall, protecting the bacterial cell from osmotic pressure. Lipopolysaccharides (A) are found in the outer membrane of Gram-negative bacteria. Cellulose (B) is a component of plant cell walls, not bacterial cell walls. Chitin (D) is a polysaccharide found in the exoskeletons of arthropods and fungi, not in bacterial cell walls.

Question 5 of 5

The Ziehl-Neelsen stain is used to detect:

Correct Answer: B

Rationale: The Ziehl-Neelsen stain is specifically designed to detect acid-fast bacteria like Mycobacterium tuberculosis. It utilizes a carbol fuchsin dye that binds to the high lipid content in the cell wall of acid-fast bacteria, making them appear red under a microscope. This staining method is crucial for the diagnosis of tuberculosis and leprosy. Gram-positive bacteria (Choice A) are not detected by this stain since they have a different cell wall structure. Capsulated bacteria (Choice C) and fungal spores (Choice D) also have distinct characteristics that are not targeted by the Ziehl-Neelsen stain.

Similar Questions

Join Our Community Today!

Join Over 10,000+ nursing students using Nurselytic. Access Comprehensive study Guides curriculum for ATI-RN and 3000+ practice questions to help you pass your ATI-RN exam.

Call to Action Image