ATI RN
mastering microbiology test bank Questions
Question 1 of 9
Which of the following bacteria are unable to synthesize ATP?
Correct Answer: A
Rationale: The correct answer is A: Chlamydia. Chlamydia lacks the essential enzymes for ATP synthesis and relies on host cell ATP. Enterococci, Rickettsia, and Staphylococci possess the necessary enzymes for ATP synthesis through cellular respiration. Chlamydia's inability to synthesize ATP makes it dependent on the host cell for energy production, distinguishing it from the other bacteria listed.
Question 2 of 9
Bypass fume hoods belong to the group of
Correct Answer: A
Rationale: The correct answer is A: general-purpose hoods. Bypass fume hoods are designed to handle a wide range of chemical fumes and vapors, making them suitable for various types of experiments and processes. They are not specifically designed for radioisotopes (B), perchloric acid (C), or biological materials (D). Therefore, A is the correct choice for bypass fume hoods.
Question 3 of 9
A patient with a deep tissue infection had a wound culture revealing Gram-positive cocci in clusters. The bacteria were catalase-positive and coagulase-negative. What is the most likely causative agent?
Correct Answer: A
Rationale: The correct answer is A: Staphylococcus epidermidis. The presence of Gram-positive cocci in clusters that are catalase-positive and coagulase-negative points towards coagulase-negative staphylococci like Staphylococcus epidermidis. Staphylococcus aureus is catalase-positive and coagulase-positive. Streptococcus pyogenes is catalase-negative. Enterococcus faecalis is catalase-negative and not typically seen in clusters. Therefore, the most likely causative agent in this scenario is Staphylococcus epidermidis.
Question 4 of 9
All of the following areas of the human body contain normal flora except:
Correct Answer: A
Rationale: The correct answer is A: Peritoneum. Normal flora refers to the microorganisms that naturally inhabit the human body without causing harm. The peritoneum is a sterile area, so it does not harbor normal flora. The urethra, vagina, and mouth all have normal flora due to their moist and warm environments, which provide an ideal habitat for microorganisms to thrive. The peritoneum, being a sterile cavity that houses organs like the stomach and intestines, does not have a natural microbial population like the other areas mentioned. Therefore, it does not contain normal flora.
Question 5 of 9
What is the primary mode of transmission for tetanus?
Correct Answer: C
Rationale: The correct answer is C: Contaminated wounds. Tetanus is caused by the bacterium Clostridium tetani, which enters the body through breaks in the skin such as wounds or cuts. The bacteria produce a toxin that affects the nervous system, leading to muscle stiffness and spasms. Ingestion of contaminated food (choice A) is not a mode of transmission for tetanus. Inhalation of droplets (choice B) is more relevant for respiratory infections. Direct physical contact (choice D) is not the primary mode of transmission for tetanus as the bacteria need a portal of entry such as a wound to cause infection.
Question 6 of 9
A 34-year-old male visited Tajikistan. After return, he complains of fever up to 40oC which occurs every second day and is accompanied by chills, sweating. Hepatosplenomegaly is present. Blood test results: RBC- 3x1012/l, b- 80 g/l, WBC- 4x109/l, eosinophils - 1%, stab neutrophils - 5%, segmented neutrophils - 60%, lymphocytes - 24%, monocytes - 10%, ESR - 25 mm/h. What is the provisional diagnosis?
Correct Answer: A
Rationale: The correct answer is A: Malaria. The patient's travel history to an endemic area like Tajikistan, along with symptoms of fever with chills, sweating, and hepatosplenomegaly, are classic for malaria. The blood test results show anemia (low RBC and hemoglobin levels), which can occur in malaria due to hemolysis. The presence of eosinophils and lymphocytes are not typical for malaria, but the overall clinical picture fits. Infectious mononucleosis (choice B) typically presents with sore throat, lymphadenopathy, and atypical lymphocytosis, which are not seen in this case. Sepsis (choice C) is characterized by systemic inflammatory response syndrome and organ dysfunction due to infection, which does not align with the symptoms and findings in the case. Typhoid fever (choice D) usually presents with gradual onset of sustained fever, abdominal pain, headache, and constipation, which are not present in this patient
Question 7 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 eukaryotic microorganisms, meaning they have a true nucleus and membrane-bound organelles. This relates to the question as eukaryotes are organisms with complex cells containing these features. Viruses (B) are non-living entities that require a host cell to replicate, lacking cellular structures. Viroids (C) are smaller than viruses and consist of only RNA, lacking a protein coat. Prions (D) are misfolded proteins causing diseases but are not considered microorganisms nor do they have cellular structure. Thus, protozoa are the only eukaryotic microorganism group among the options.
Question 8 of 9
The causative agent of the disease gas gangrene Clostridium perfringens is:
Correct Answer: C
Rationale: The correct answer is C because Clostridium perfringens is a Gram-positive rod-shaped bacterium, which matches the description provided. It is motile and peritrichous (having flagella all over the surface) without a capsule. This bacterium is known to cause gas gangrene due to its ability to produce toxins that destroy tissue. Choice A is incorrect because Clostridium perfringens is Gram-positive, not Gram-negative, and it does not have a capsule. Choice B is incorrect because Clostridium perfringens is not motile and does not have flagella all over its surface. Choice D is incorrect because Clostridium perfringens is Gram-positive, not Gram-negative, and it is motile without a capsule.
Question 9 of 9
Production of auto-antibodies may be due to:
Correct Answer: D
Rationale: Production of auto-antibodies can be due to various factors. Mutant B cell clones can lead to the production of self-reactive antibodies. Antibodies against hidden tissues can also trigger autoimmune responses. Genetic factors play a crucial role in predisposing individuals to autoimmunity. Therefore, the correct answer is D, as all these factors can contribute to the production of auto-antibodies. Choice A is incorrect as it only addresses one possible cause. Choice B is incorrect as it focuses solely on antibodies against hidden tissues. Choice C is incorrect as it overlooks the other potential reasons for auto-antibody production.