Nokea
A phage in a repressed stage is referred to as a(n)
- A. antiphage.
- B. prophage.
- C. virulent phage.
- D. latent phage.
Correct Answer: B
Rationale: The correct answer is B: prophage. In the repressed stage, a phage integrates its DNA into the host cell's chromosome, becoming a prophage. This integration allows the phage to replicate along with the host cell without causing immediate lysis.
A: Antiphage is not a term used to describe a phage in a repressed stage.
C: Virulent phage refers to a phage that immediately causes lysis of the host cell.
D: Latent phage is not a commonly used term in this context.
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Autoclaving will usually destroy/inactivate all fungi, bacteria, viruses, and most bacterial spores but will not necessarily eliminate
- A. neurotoxins.
- B. prions.
- C. protozoan cysts.
- D. mycoplasmas.
Correct Answer: B
Rationale: The correct answer is B: prions. Autoclaving, a method of sterilization using high pressure and steam, is effective at destroying most microorganisms including fungi, bacteria, viruses, and most bacterial spores due to denaturation of their proteins and nucleic acids. However, prions are highly resistant infectious proteins that are not easily eliminated by autoclaving. Prions can withstand high temperatures and pressure, making them a challenge to eradicate. Neurotoxins (A), protozoan cysts (C), and mycoplasmas (D) are susceptible to autoclaving and would be destroyed during the process.
Which bacteria are responsible for causing 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) because different bacteria can cause pneumonia. Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Mycobacterium tuberculosis causes tuberculosis, which can lead to pneumonia. Pseudomonas aeruginosa is a common cause of hospital-acquired pneumonia. Therefore, all three bacteria can be responsible for causing pneumonia in different contexts. Choices A, B, and C are incorrect because each bacterium individually can cause pneumonia, so selecting only one option would not cover the full spectrum of bacterial causes of pneumonia.
Bacteria that have a single polar flagellum at one end are referred to as:
- A. monotrichous
- B. monotrichous
- C. amphitrichous
- D. peritrichous
Correct Answer: B
Rationale: Step-by-step rationale:
1. Monotrichous means having a single flagellum at one end.
2. The term "polar" indicates that the flagellum is located at one end of the bacterium.
3. Therefore, bacteria with a single polar flagellum are referred to as monotrichous.
4. Choice A is a typo, as it is the same as the correct answer B.
Summary:
- Choice A is a typo, as it duplicates the correct answer.
- Choice C, amphitrichous, refers to bacteria with a flagellum at each end.
- Choice D, peritrichous, describes bacteria with flagella distributed over the entire surface.
Widal test is used to diagnose
- A. Syphilis
- B. Typhoid fever
- C. AIDS
- D. Lyme disease
Correct Answer: B
Rationale: The Widal test is used to diagnose typhoid fever caused by the bacteria Salmonella typhi. The test detects antibodies produced in response to the bacteria. Positive results indicate a current or past infection with typhoid fever. Choice A (Syphilis) is incorrect as it is diagnosed using different tests like RPR or TPPA. Choice C (AIDS) is diagnosed with HIV tests like ELISA or Western blot. Choice D (Lyme disease) is diagnosed using tests like ELISA or Western blot specific for Borrelia burgdorferi.
Subcutaneous mycoses occur predominantly in the:
- A. tropics
- B. deserts
- C. forests of the Northern Hemisphere
- D. Rocky Mountains
Correct Answer: A
Rationale: Subcutaneous mycoses are fungal infections that affect the skin, subcutaneous tissues, and bones. The correct answer is A: tropics, as these infections are more commonly found in warm and humid regions. Fungi that cause subcutaneous mycoses thrive in tropical climates due to the favorable conditions for their growth and transmission. Choices B, C, and D are incorrect because deserts (B) have dry conditions not conducive to fungal growth, forests of the Northern Hemisphere (C) have varying climates that may not support the specific fungi causing subcutaneous mycoses, and the Rocky Mountains (D) are not typically associated with the high humidity required for these infections.