Nokea
Bacteria that require low oxygen concentrations for growth are called:
- A. Facultative anaerobes
- B. Obligate aerobes
- C. Microaerophiles
- D. Obligate anaerobes
Correct Answer: C
Rationale: The correct answer is C: Microaerophiles. These bacteria grow best in environments with low oxygen levels. They require oxygen for respiration but at lower concentrations than what is present in the atmosphere. This allows them to thrive in conditions where oxygen is limited but not completely absent.
A: Facultative anaerobes can grow in both the presence and absence of oxygen.
B: Obligate aerobes require oxygen for growth.
D: Obligate anaerobes cannot survive in the presence of oxygen and typically grow in anaerobic environments.
In summary, microaerophiles are the correct choice as they specifically thrive in low oxygen environments, distinguishing them from the other options.
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Which one is an example of an immunomodulator:
- A. Rifampin
- B. Gamma Interferon
- C. Hexacima
- D. Pentaxim
Correct Answer: B
Rationale: Step-by-step rationale for why B (Gamma Interferon) is the correct answer:
1. Gamma Interferon is a type of immunomodulator that helps regulate the immune response.
2. It activates macrophages and enhances the immune system's ability to fight infections.
3. Rifampin is an antibiotic, not an immunomodulator.
4. Hexacima and Pentaxim are combination vaccines, not immunomodulators.
In summary, Gamma Interferon is the correct answer as it directly influences the immune response, while the other choices are not immunomodulators.
Quite often, the soil may contain a number of pathogenic microorganisms. The causative agents of the following disease may exist in the soil for a long time:
- A. Anthrax
- B. Diphtheria
- C. Viral hepatitis
- D. Pertussis
Correct Answer: A
Rationale: The correct answer is A: Anthrax. Anthrax is caused by the bacterium Bacillus anthracis, which can form spores that are highly resistant and can survive in the soil for long periods. These spores can remain dormant until they come into contact with a susceptible host, leading to infection. Diphtheria, viral hepatitis, and pertussis are caused by different types of pathogens (bacteria and viruses) that do not have the same ability to persist in soil as anthrax spores. Therefore, the causative agents of these diseases are less likely to exist in the soil for extended periods compared to anthrax spores.
Anti-influenza drugs that target the neuraminidase are;
- A. Maxi Grip and Tamiflu
- B. Theraflu and Relenza
- C. Amantadine and Rimantadine
- D. Relenza and Tamiflu
Correct Answer: D
Rationale: The correct answer is D: Relenza and Tamiflu. Both Relenza and Tamiflu are anti-influenza drugs that target the neuraminidase enzyme of the influenza virus, thereby inhibiting its replication and spread. Maxi Grip (A) is not an anti-influenza drug, Theraflu (B) contains different active ingredients, and Amantadine and Rimantadine (C) target a different viral protein, M2 ion channel. Therefore, choices A, B, and C are incorrect as they do not specifically target neuraminidase for influenza treatment.
Granulomas containing lymphocytes and macrophages were detected during analysis of skin biopsy material. Among macrophages there are large cells with fat inclusions, which contain microorganisms in spheric packages (Virchow's cells). The following disease is based on the described type of hypersensitivity:
- A. Leprosy
- B. Syphilis
- C. Tuberculosis
- D. Rhinoscleroma
Correct Answer: C
Rationale: The correct answer is C: Tuberculosis. Granulomas with lymphocytes and macrophages containing Virchow's cells (large cells with fat inclusions containing microorganisms) are classic findings in tuberculosis. Leprosy (A) typically presents with granulomas but with different histopathological features. Syphilis (B) does not usually form granulomas in the skin. Rhinoscleroma (D) is a chronic bacterial infection characterized by nodular lesions but does not typically involve Virchow's cells as seen in tuberculosis.
The optimal PH for most pathogenic bacteria and viruses is:
- A. 5.0-5.5
- B. 8.0-9.6
- C. 7.2-7.4
- D. 4.2-4.4
Correct Answer: C
Rationale: The correct answer is C (7.2-7.4) because most pathogenic bacteria and viruses thrive in a neutral pH environment close to 7.0. This pH range is optimal for their growth and survival. Choice A (5.0-5.5) is too acidic for most pathogens. Choice B (8.0-9.6) is too alkaline, which is not conducive for their survival. Choice D (4.2-4.4) is also too acidic and would likely inhibit the growth of pathogenic bacteria and viruses. Thus, a pH range of 7.2-7.4 provides the most suitable conditions for their proliferation.