ATI RN
microbiology an introduction 12th edition test bank Questions
Question 1 of 9
The enzyme required for replication of viral RNA is:
Correct Answer: C
Rationale: The correct answer is C: RNA-dependent RNA polymerase. This enzyme is required for replicating viral RNA due to its ability to catalyze the synthesis of RNA using an RNA template. Reverse transcriptase (A) is used to transcribe RNA into DNA, not replicate viral RNA. DNA polymerase (B) is used for replicating DNA, not RNA. Ligase (D) is involved in joining DNA fragments, not in replicating viral RNA. Therefore, RNA-dependent RNA polymerase is the only enzyme that specifically performs the function required for replicating viral RNA.
Question 2 of 9
Enzymes that remove functional groups from a substrate without adding water, or that add functional groups to a double bond, are called
Correct Answer: D
Rationale: The correct answer is D: lyases. Lyases are enzymes that catalyze the breaking of chemical bonds without the addition of water. They can remove functional groups from substrates or add functional groups to double bonds without the use of water. A: Oxidoreductases involve the transfer of electrons. B: Transferases transfer functional groups from one molecule to another. C: Hydrolases catalyze the breaking of bonds by adding water.
Question 3 of 9
Microbiological analysis of medicinal raw materials revealed capsular bacteria. What stain method was used to detect the capsules?
Correct Answer: A
Rationale: The correct answer is A: Gin's stain method. Gin's stain method is specifically used to detect capsules of bacteria. This method involves staining the bacteria with crystal violet and copper sulfate, which highlights the capsules as a clear halo around the stained bacterial cells. Ziehl-Neelsen's stain is used for acid-fast bacteria like Mycobacterium tuberculosis, Neisser's stain is for detecting Neisseria species, and Gram's stain is for differentiating bacteria based on their cell wall composition (Gram-positive vs. Gram-negative). Therefore, choices B, C, and D are incorrect for this scenario.
Question 4 of 9
Bacteriological inspection of disinfection quality at a pharmacy revealed a microorganism in an utility room (in the sink). The microorganism has the following properties: mobile nonspore-forming gram- negative bacteria that form capsular substance, grow well on ordinary nutrient media, secrete the blue-green pigment. This microorganism is most likely to be of the following genus:
Correct Answer: A
Rationale: The correct answer is A: Pseudomonas. Rationale: 1. Mobile nonspore-forming gram-negative bacteria with a capsule substance indicate Pseudomonas. 2. Pseudomonas grow well on ordinary nutrient media, matching the description. 3. The secretion of a blue-green pigment is a characteristic feature of Pseudomonas. 4. Proteus is a gram-negative bacterium but does not match all the given properties. 5. Clostridium is a gram-positive bacterium that forms spores. 6. Shigella is a gram-negative bacterium but does not have the other characteristics mentioned. Therefore, based on the properties described, the most likely genus of the microorganism is Pseudomonas.
Question 5 of 9
What differentiates facultative anaerobes from obligate anaerobes?
Correct Answer: B
Rationale: Facultative anaerobes can switch between aerobic and anaerobic metabolism based on oxygen availability. This flexibility enables them to grow in both oxygen-rich and oxygen-poor environments, making choice B correct. Choice A is incorrect because facultative anaerobes do not require oxygen for survival. Choice C is incorrect as obligate anaerobes cannot grow in the presence of oxygen. Choice D is incorrect because obligate anaerobes cannot tolerate any amount of oxygen.
Question 6 of 9
The neonatal infection referred to as “sticky eye†is caused by:
Correct Answer: C
Rationale: The correct answer is C: Staphylococcus. Staphylococcus is a common bacteria that can cause neonatal conjunctivitis, also known as "sticky eye." Staphylococcal conjunctivitis presents with symptoms like eye redness, discharge, and swelling. Streptococcus (choice A) typically causes throat infections, herpes simplex (choice B) causes genital or oral sores, and Escherichia (choice D) is a bacteria commonly found in the gastrointestinal tract and is not typically associated with neonatal conjunctivitis. Therefore, the most likely pathogen causing "sticky eye" in newborns is Staphylococcus.
Question 7 of 9
A patient being treated for tuberculosis is suffering from hearing deterioration. What drug causes this complication?
Correct Answer: A
Rationale: The correct answer is A: Streptomycin. Streptomycin is an aminoglycoside antibiotic used to treat tuberculosis that can cause hearing loss as a side effect. It is known to damage the cochlear and vestibular organs in the inner ear. The other choices, B: Isoniazid, C: Rifampicin, and D: Ethionamide, are not associated with causing hearing deterioration as a side effect. Isoniazid can rarely cause peripheral neuropathy, Rifampicin can lead to hepatotoxicity, and Ethionamide may cause gastrointestinal disturbances, but none of these drugs are known to specifically cause hearing loss.
Question 8 of 9
The most common bacterial nonsexually transmitted infection of the male reproductive system is:
Correct Answer: B
Rationale: The correct answer is B: prostatitis. Prostatitis is the most common bacterial infection affecting the male reproductive system. It is characterized by inflammation of the prostate gland due to bacterial infection. Symptoms include pain in the pelvic area, difficulty urinating, and fever. Cystitis (A) is a bladder infection, not specific to the male reproductive system. Mastitis (C) is inflammation of the breast tissue, which is not related to the male reproductive system. Nephritis (D) is inflammation of the kidneys, which is also not specific to the male reproductive system.
Question 9 of 9
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.