ATI RN
microbiology test bank Questions
Question 1 of 9
Which one of the following statements about the cytoplasmic membrane of the prokaryotes is true?
Correct Answer: B
Rationale: The correct answer is B because the structure of the cytoplasmic membrane in gram-positive and gram-negative bacteria is fundamentally different. Gram-positive bacteria have a single-layered cytoplasmic membrane, while gram-negative bacteria have a double-layered cytoplasmic membrane with an additional outer membrane. This key difference is crucial for various functions such as antibiotic resistance and nutrient transport. Rationale for the incorrect choices: A: Gram-positive bacteria have a single-layered cytoplasmic membrane, not a double-layered one. C: Prokaryotes do have a cytoplasmic membrane, which is essential for maintaining cell integrity and regulating the passage of molecules. D: Gram-negative bacteria have a double-layered cytoplasmic membrane, not a three-layered one.
Question 2 of 9
Etiological factors for the infectious diseases are often microorganisms with various ultrastructure. Which of the following microorganism groups relates to the eukaryotes?
Correct Answer: A
Rationale: The correct answer is A: Protozoa. Protozoa are single-celled eukaryotic organisms, meaning they have a nucleus and other membrane-bound organelles. Eukaryotes have complex cellular structures that include a nucleus, mitochondria, and other organelles. Therefore, protozoa are eukaryotes. Viruses (B) are not considered cells and lack cellular structures. Viroids (C) are smaller infectious agents that consist of only RNA, lacking the cellular structure of eukaryotes. Prions (D) are infectious proteins and do not possess cellular structures like eukaryotes. So, protozoa are the only choice that relates to eukaryotes due to their cellular structure.
Question 3 of 9
A patient with pneumonia had sputum cultured revealing Gram-positive diplococci. The bacteria were catalase-negative and alpha-hemolytic. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Streptococcus pneumoniae. The given characteristics match this bacterium: Gram-positive diplococci, catalase-negative, and alpha-hemolytic. S. pneumoniae is a common cause of community-acquired pneumonia. Other choices are incorrect because Staphylococcus aureus is catalase-positive, Enterococcus faecalis is not alpha-hemolytic, and Klebsiella pneumoniae is not Gram-positive diplococci.
Question 4 of 9
Structures and organs of the immune system are lymphatic system, lymphoid tissue, lymph nodes, thymus, spleen.
Correct Answer: A
Rationale: The correct answer is A: TRUE. The structures and organs listed are indeed part of the immune system. The lymphatic system transports lymph, lymphoid tissue contains immune cells, lymph nodes filter lymph, thymus matures T-cells, and spleen filters blood and produces immune cells. This comprehensive network is crucial for defending the body against pathogens. Choice B is incorrect as all listed structures are components of the immune system. Choice C is also incorrect as the statement is universally true, not situational. Choice D is incorrect as the correct answer is A.
Question 5 of 9
A 5-year-old kindergartener has diphtheria. To find the carriers of the disease among the kindergarten staff, samples of pharyngeal mucus were obtained from the employers. One of the employers had gram-positive bacilli in her sample. They were situated at an angle to each other and colored unevenly, when stained according to Loeffler. What method can confirm that this carrier is dangerous to other people?
Correct Answer: A
Rationale: The correct answer is A: Toxin production test. Rationale: 1. Diphtheria is caused by a toxin produced by Corynebacterium diphtheriae. 2. To confirm if the carrier is dangerous, we need to test if they are producing the toxin. 3. The toxin production test directly assesses if the bacteria are producing the harmful toxin. 4. Positive results indicate the carrier is dangerous and can transmit the disease to others. Summary of other choices: B: Mouse neutralization test - Used to detect diphtheria antitoxin levels in blood, not to confirm if the carrier is dangerous. C: Immunofluorescence test - Used to detect specific antigens or antibodies, not directly related to confirming the carrier's danger. D: Complement fixation test - Measures immune response, not specific to toxin production confirmation.
Question 6 of 9
Routine investigation of microbiological sanitary condition of air in a hospital is performed once in 3 months. What microorganism is the sanitary indicator of air condition in an enclosed space?
Correct Answer: D
Rationale: The correct answer is D: P.aeruginosa. This bacterium is commonly found in water and soil, making its presence in indoor air an indicator of poor sanitation. Step 1: P.aeruginosa is an opportunistic pathogen known to cause infections in hospitals. Step 2: Its presence in the air indicates potential contamination and poor air quality. Step 3: Regular monitoring of P.aeruginosa levels can help assess the effectiveness of sanitation measures. Summary: A, B, and C are not suitable indicators of air sanitation in an enclosed space as they are not typically associated with environmental contamination or poor air quality.
Question 7 of 9
During the staining of sputum smear of a patient with suspected croupous pneumonia the following reactives and stainers were used: gentian violet solution, Lugol's solution, 960 spiritus and water fuchsin. What method of staining is used in this case?
Correct Answer: A
Rationale: The correct answer is A: Leffler's method. In this staining method, gentian violet solution is used as the primary stain, followed by Lugol's solution as a mordant, 960 spiritus as a decolorizer, and water fuchsin as a counterstain. Gentian violet stains the organisms purple, Lugol's solution helps in fixing the dye, 960 spiritus decolorizes non-specifically, and water fuchsin acts as a counterstain to help visualize the bacteria. Leffler's method is specifically used for staining sputum smears in suspected cases of croupous pneumonia. Summary: B: Gram's staining uses crystal violet, iodine, alcohol, and safranin. It is mainly used for distinguishing between Gram-positive and Gram-negative bacteria. C: Ziehl-Neelsen's staining is used for acid-fast bacteria like Mycobacterium tuberculosis using carbol fuchsin and acid-alcohol
Question 8 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 9 of 9
Which of the following pathogens has the widest infectious spectrum?
Correct Answer: D
Rationale: The correct answer is D, the rabies virus. Rabies virus has the widest infectious spectrum among the given choices because it can infect a wide range of mammals, including humans. This is due to its ability to infect nerve cells and spread throughout the central nervous system. The other choices have more limited infectious spectra. Anthrax bacillus primarily infects herbivores and humans, mumps virus infects mainly humans, and the causative agent of gonorrhea primarily infects humans through sexual contact. Therefore, the rabies virus is the correct answer as it has the broadest range of potential hosts.