ATI RN
mcgraw hill microbiology test bank Questions
Question 1 of 9
Which of the following microorganisms are acid-fast?
Correct Answer: B
Rationale: The correct answer is B: Mycobacterium tuberculosis. Acid-fast bacteria have a unique cell wall component called mycolic acid, making them resistant to decolorization by acid-alcohol during staining. Mycobacterium tuberculosis is acid-fast, as it retains the stain due to its high lipid content. Streptococcus pyogenes (A), Clostridium perfringens (C), and Bacillus subtilis (D) do not possess mycolic acid in their cell walls, so they are not acid-fast.
Question 2 of 9
Beadlike chains of cocci formed after cell division along a single axis are called:
Correct Answer: B
Rationale: The correct answer is B: streptococci. This term refers to beadlike chains of cocci formed after cell division along a single axis. "Diplococci" (A) are pairs of cocci, "tetrads" (C) are groups of four cocci, and "sarcinae" (D) are cube-like groups of eight cocci. Streptococci is the most appropriate term for describing the specific arrangement mentioned in the question.
Question 3 of 9
A 23 year old female patient complains about periodical chill and body temperature rise up to 40oC, sense of heat taking turns with profuse sweating. The patient has had already 3 attacks that came once in two days and lasted 12 hours. She has lived in Africa for the last 2 months. Liver and spleen are enlarged. In blood: erythrocytes - 2,5x1012/l. What is the most probable diagnosis?
Correct Answer: A
Rationale: The most probable diagnosis is A: Malaria. The patient's symptoms of periodic chills, high fever, and profuse sweating, along with living in Africa where malaria is endemic, strongly suggest malaria. The enlarged liver and spleen are consistent with malaria infection. The low erythrocyte count indicates hemolysis, a common feature of malaria. Spotted fever and sepsis do not typically present with the same pattern of symptoms and travel history as seen in this case. Haemolytic anaemia would not explain the patient's fever episodes and other symptoms. Therefore, based on the symptoms, travel history, and laboratory findings, malaria is the most likely diagnosis.
Question 4 of 9
The enzyme that breaks down the peptidoglycan in bacterial cell walls is:
Correct Answer: A
Rationale: The correct answer is A: Lysozyme. Lysozyme is an enzyme that targets and breaks down the peptidoglycan in bacterial cell walls by cleaving the glycosidic bonds between the sugar components. This action weakens the cell wall, leading to bacterial cell lysis. Amylase (B) breaks down starch, not peptidoglycan. Protease (C) breaks down proteins, not peptidoglycan. Lipase (D) breaks down lipids, not peptidoglycan. Therefore, Lysozyme is the correct enzyme for breaking down peptidoglycan in bacterial cell walls.
Question 5 of 9
A laboratory received a sample of water used in drug production for sanitary and viral analysis. What group of viruses will indicate fecal contamination of water and thus the need for its additional purification?
Correct Answer: A
Rationale: The correct answer is A: Picornaviridae. Picornaviruses, such as enteroviruses, are commonly found in the feces of infected individuals. Therefore, their presence in water indicates fecal contamination and the need for additional purification. B: Herpesviridae are not typically associated with fecal contamination. C: Flaviviridae are mainly transmitted through arthropods like mosquitoes, not fecal contamination. D: Retroviridae, including HIV, are not typically excreted in high levels in feces and are not indicators of fecal contamination.
Question 6 of 9
In 8 days after a surgery the patient develops tetatus. The surgeon suspects this condition to be caused by suture material contaminated by tetanus agent. The material is delivered to a bacteriological laboratory. What nutrient medium is required for primary inoculation of the suture material?
Correct Answer: D
Rationale: The correct answer is D, Kitt-Tarozzi medium. This medium is specifically designed for the isolation and cultivation of Clostridium tetani, the bacteria responsible for tetanus. The other options, Sabouraud agar, Endo agar, and Hiss medium, are not suitable for the growth of Clostridium tetani. Sabouraud agar is used for fungal cultures, Endo agar is a selective medium for enteric bacteria, and Hiss medium is used for the cultivation of anaerobic bacteria other than Clostridium tetani. Therefore, the Kitt-Tarozzi medium is the most appropriate choice for isolating and identifying the tetanus agent in this scenario.
Question 7 of 9
The causative agent of the pertussis (also known as whooping cough) morphologically appears as:
Correct Answer: B
Rationale: The correct answer is B: Gram negative coccobacillus. Bordetella pertussis, the causative agent of pertussis, is a gram-negative coccobacillus. This is because it is a small, rod-shaped bacterium that appears both as a bacillus (rod-shaped) and a coccus (spherical) shape. It does not retain the crystal violet stain in the Gram staining process, indicating its negative gram nature. Choice A is incorrect because pertussis is not a gram-positive bacillus. Choice C is incorrect because pertussis is not a long gram-negative rod-shaped bacterium. Choice D is incorrect as the other options do not accurately describe the morphology of Bordetella pertussis.
Question 8 of 9
The distinctive pattern of adenoviruses is due to;
Correct Answer: D
Rationale: The correct answer is D: Fibers at the vertices of the icosahedron. Adenoviruses have fibers at the vertices of the icosahedron, which give them their distinctive pattern. These fibers help in attaching to host cells. Choices A, B, and C are incorrect because adenoviruses do not have a lipid envelope, helical capsid, or ssDNA. Adenoviruses have a non-enveloped icosahedral capsid and contain dsDNA. This makes choice D the correct answer as it specifically relates to the unique structural feature of adenoviruses.
Question 9 of 9
Which type of bacteria can survive in both aerobic and anaerobic environments?
Correct Answer: B
Rationale: Certainly! The correct answer is B: Facultative anaerobes. Facultative anaerobes can survive in both aerobic and anaerobic environments due to their ability to switch between utilizing oxygen for respiration in aerobic conditions and utilizing fermentation or anaerobic respiration in anaerobic conditions. This flexibility allows them to thrive in diverse environments. Explanation for incorrect choices: A: Obligate aerobes require oxygen for respiration and cannot survive in anaerobic environments. C: Obligate anaerobes can only survive in the absence of oxygen and would not thrive in aerobic conditions. D: Microaerophiles require low levels of oxygen to grow and are not as versatile in adapting to varying oxygen levels compared to facultative anaerobes.