Nokea
Algae that contain agar in their cell walls belong to:
- A. Chrysophyta
- B. Rhodophyta
- C. Chlorophyta
- D. Phaeophyta
Correct Answer: B
Rationale: The correct answer is B: Rhodophyta. Rhodophyta is the phylum of red algae, which are known to contain agar in their cell walls. Agar is a gelatinous substance derived from these algae. Chrysophyta (A), Chlorophyta (C), and Phaeophyta (D) do not typically contain agar in their cell walls. Chrysophyta includes diatoms, Chlorophyta includes green algae, and Phaeophyta includes brown algae, none of which are known for agar production. Therefore, Rhodophyta is the correct choice based on the presence of agar in their cell walls.
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Which of the following bacteria is a common cause of pneumonia?
- A. Streptococcus pneumoniae
- B. Mycobacterium tuberculosis
- C. Pseudomonas aeruginosa
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D: All of the above.
- Streptococcus pneumoniae is a common cause of community-acquired pneumonia.
- Mycobacterium tuberculosis can cause pulmonary tuberculosis, which can present as pneumonia-like symptoms.
- Pseudomonas aeruginosa is an opportunistic pathogen that can cause pneumonia in immunocompromised individuals.
Therefore, all three bacteria can cause pneumonia, making option D the correct choice. Options A, B, and C are incorrect because they each represent a bacterium that can cause pneumonia, so only selecting one of them would not encompass all common causes of pneumonia.
Penicillin-resistant, beta-lactamase-producing strains must be detected..
- A. After antibiotic therapy is begun
- B. Before antibiotic therapy is begun
- C. During the antibiotic therapy
- D. No importance for the time of detection
Correct Answer: B
Rationale: The correct answer is B: Before antibiotic therapy is begun. Detecting penicillin-resistant, beta-lactamase-producing strains before antibiotic therapy is crucial to ensure proper treatment. If detected after therapy (choice A), it may lead to treatment failure. Detection during therapy (choice C) may result in delayed or ineffective treatment. Choice D is incorrect as early detection is essential for successful management.
All of the statements about Rotaviruses are correct EXCEPT
- A. non-specific antiviral therapy is available
- B. Rotaviruses are ubiquitous worldwide
- C. Rotaviruses are a major cause of meningitis
- D. large amounts of viruses are released in fecal matter
Correct Answer: C
Rationale: The correct answer is C because Rotaviruses are not a major cause of meningitis; they primarily cause gastroenteritis. This is because Rotaviruses infect the gastrointestinal tract, not the central nervous system. Choice A is incorrect because there is no specific antiviral therapy for Rotaviruses. Choice B is correct as Rotaviruses are indeed widespread globally. Choice D is correct as Rotaviruses are shed in large amounts in feces, contributing to their ability to spread easily.
A centrifugate of urine sample obtained from patient with suspected renal tuberculosis was used to make a slide mount for microscopy. What method should be used to stain the slide and detect the causative agent?
- A. Zielh-Neelsen stain
- B. Loeffler stain
- C. Gram stain
- D. Aujeszky stain
Correct Answer: A
Rationale: The correct answer is A: Zielh-Neelsen stain. This stain is specifically used to detect acid-fast bacteria like Mycobacterium tuberculosis, the causative agent of renal tuberculosis. The staining process involves using carbol fuchsin to penetrate the mycolic acid layer of the bacterial cell wall, making it resistant to decolorization with acid-alcohol. This allows the red stained bacteria to be visualized under a microscope. Loeffler stain (B) is used for staining bacteria like diphtheria bacilli, Gram stain (C) is used for bacterial classification based on cell wall properties, and Aujeszky stain (D) is not a recognized staining method for detecting acid-fast bacteria.
Typhoid fever is caused by the bacterium:
- A. Escherichia coli
- B. Salmonella enterica
- C. Shigella flexneri
- D. Staphylococcus aureus
Correct Answer: B
Rationale: The correct answer is B: Salmonella enterica. Typhoid fever is caused by the bacterium Salmonella enterica serotype Typhi. This specific strain of Salmonella is responsible for typhoid fever, a serious illness characterized by high fever, abdominal pain, and diarrhea. Escherichia coli (choice A) is not the causative agent of typhoid fever. Shigella flexneri (choice C) causes bacillary dysentery, not typhoid fever. Staphylococcus aureus (choice D) can cause food poisoning but is not associated with typhoid fever.