ATI RN
mcgraw hill microbiology test bank Questions
Question 1 of 9
Which of the following best describes the role of bacterial plasmids?
Correct Answer: B
Rationale: The correct answer is B: Carrying antibiotic resistance genes. Bacterial plasmids are small, circular DNA molecules that can carry genes, including those for antibiotic resistance. This allows bacteria to survive exposure to antibiotics. Plasmids do not directly regulate bacterial growth (A), produce toxins (C), or facilitate endospore formation (D). Plasmids play a crucial role in the spread of antibiotic resistance among bacteria.
Question 2 of 9
An outbreak of food poisoning was recorded in an urban settlement. The illness was diagnosed as botulism on the grounds of clinical presentations. What foodstuffs should be chosen for analysis in the first place in order to confirm the diagnosis?
Correct Answer: A
Rationale: The correct answer is A: Tinned food. Botulism is often caused by the botulinum toxin produced by the bacterium Clostridium botulinum, which can be present in improperly canned foods. Analyzing tinned food allows for direct detection of the toxin or bacteria, confirming the diagnosis. Potatoes, pasteurized milk, and boiled meat are less likely sources of botulism compared to tinned food, making them less suitable for initial analysis in this case.
Question 3 of 9
4 days after a patient received a gunshot wound of the middle third of the thigh soft tissues his condition suddenly began deteriorating. There are complaints of bursting pain in the wound; pain increases during the last 12 hours. Edema of skin and hypodermic tissue quickly grows. Body temperature is 38,2oC, heart rate is 102/min. The wound edges gape, are dull in color; the muscles, viable as of day before, now protrude into the wound, look boiled, are dull in color, have dirty-grey coating and fall apart when being held with forceps. What infection has developed in the wound?
Correct Answer: A
Rationale: The correct answer is A: Anaerobic infection. The sudden deterioration, bursting pain, edema, foul appearance of wound, and presence of gas are indicative of gas gangrene caused by anaerobic bacteria like Clostridium perfringens. These bacteria thrive in low oxygen environments, such as deep wound tissues. The symptoms align with the classic presentation of gas gangrene, necessitating immediate surgical intervention. Choice B: Aerobic gram-negative, is incorrect because anaerobic bacteria, not aerobic gram-negative bacteria, are responsible for gas gangrene. Choice C: Putrid, is incorrect as it is a general term referring to foul-smelling decay and does not specify the type of infection. Choice D: Aerobic gram-positive, is incorrect as gas gangrene is typically caused by anaerobic bacteria, not aerobic gram-positive bacteria.
Question 4 of 9
Babesiosis is a vector-borne, malaria-like illness caused by a:
Correct Answer: D
Rationale: The correct answer is D: protozoan. Babesiosis is caused by a protozoan parasite called Babesia. Protozoans are single-celled organisms that can cause various diseases in humans. Babesiosis is transmitted to humans through the bite of infected ticks. Bacteria (choice A), viruses (choice B), and helminths (choice C) are not responsible for causing babesiosis. Bacteria are typically responsible for diseases like Lyme disease, viruses for illnesses like Zika, and helminths for infections such as parasitic worms. Thus, the correct choice for the causative agent of babesiosis is a protozoan.
Question 5 of 9
Diatoms, major components of marine phytoplankton, belong to:
Correct Answer: A
Rationale: The correct answer is A: Chrysophyta. Diatoms are classified under the division Chrysophyta due to their unique characteristics, such as possessing a cell wall made of silica (siliceous frustule) and containing chlorophyll a and c for photosynthesis. Chrysophyta includes golden-brown algae, which diatoms are a part of. Rhodophyta (B) includes red algae, Chlorophyta (C) includes green algae, and Phaeophyta (D) includes brown algae. These choices are incorrect as they do not align with the specific characteristics and classification of diatoms within the kingdom Protista.
Question 6 of 9
Which bacteria are responsible for causing the disease known as 'whooping cough'?
Correct Answer: A
Rationale: The correct answer is A: Bordetella pertussis. Bordetella pertussis is the bacterium responsible for causing whooping cough, also known as pertussis. It produces toxins that damage the respiratory tract, leading to severe coughing fits. Haemophilus influenzae, Streptococcus pneumoniae, and Mycobacterium tuberculosis are not associated with whooping cough. Haemophilus influenzae can cause respiratory infections but not whooping cough. Streptococcus pneumoniae is known for causing pneumonia, and Mycobacterium tuberculosis causes tuberculosis, both different from whooping cough. Therefore, the correct answer is A as it is the specific bacterium linked to the disease in question.
Question 7 of 9
A patient has wound abscess. Bacteriological examination of the wound content revealed a gram- negative bacillus which forms semi-transparent mucous colonies of blue-green color with a pearlescent appearance on the beef-extract agar. Culture has a specific odor of violets or jasmine. What type of pathogen was isolated from the patient's wound?
Correct Answer: A
Rationale: Step 1: Gram-negative bacillus indicates P. aeruginosa, known for causing wound infections. Step 2: Semi-transparent mucous colonies of blue-green color with a pearlescent appearance are characteristic of P. aeruginosa. Step 3: Specific odor of violets or jasmine is a unique feature of P. aeruginosa. Therefore, the correct answer is A: P. aeruginosa. Summary: - B: P. vulgaris typically forms yellow colonies and doesn't have the characteristic odor. - C: S. aureus forms creamy white colonies, not blue-green, and has a distinct odor. - D: S. pyogenes forms grayish-white colonies and doesn't have the unique characteristics described.
Question 8 of 9
Sanitary assessment of a pond, where the children from a recreation summer camp take their swims, detected there oval cysts 50-60 micron in diameter, with 2 nuclei visible in their cytoplasm (macronucleus and micronucleus). What protozoa do these cysts belong to?
Correct Answer: D
Rationale: The correct answer is D: Lamblia. The cysts described match the characteristics of Giardia lamblia, a protozoan parasite. Giardia cysts are oval-shaped, 50-60 microns in diameter, and contain 2 nuclei (macronucleus and micronucleus). Giardia is commonly found in contaminated water sources and can cause gastrointestinal illness in humans. Incorrect choices: A: Toxoplasma - Toxoplasma gondii is a parasite that causes toxoplasmosis, transmitted through ingestion of contaminated food or water, but its cysts do not match the description given in the question. B: Amoeba - Amoebas are single-celled organisms, but they do not typically form cysts with visible nuclei as described. C: Balantidium - Balantidium coli is a ciliated protozoan that can cause dysentery in humans, but its cysts do not
Question 9 of 9
A patient with suspected liver abscess was admitted to the surgical department. The patient had been staying for a long time on business in one of African countries and fell repeatedly ill with acute gastrointestinal disorders. What protozoal disease may the patient be now ill with?
Correct Answer: A
Rationale: Rationale: The correct answer is Amebiasis (choice A) because the patient's symptoms of acute gastrointestinal disorders and prolonged stay in an African country suggest exposure to Entamoeba histolytica, the causative agent of amebiasis. This protozoal infection commonly occurs in tropical regions, including Africa. Trypanosomosis (choice B) is caused by Trypanosoma species transmitted by tsetse flies, primarily found in sub-Saharan Africa. Leishmaniasis (choice C) is transmitted by sandflies and presents with skin lesions or visceral involvement, not acute gastrointestinal symptoms. Malaria (choice D) is caused by Plasmodium parasites transmitted by mosquitoes and typically presents with fever, not acute gastrointestinal disorders. Therefore, choices B, C, and D are incorrect based on the patient's clinical presentation and travel history.