Nokea
Microscopy of stained (Ziehl-Neelsen staining) smears taken from the sputum of a patient with chronic pulmonary disease revealed red bacilli. What property of tuberculous bacillus was shown up?
- A. Acid resistance
- B. Alkali resistance
- C. Alcohol resistance
- D. Capsule formation
Correct Answer: A
Rationale: The correct answer is A: Acid resistance. Tuberculous bacilli are acid-fast bacilli, meaning they resist decolorization by acid-alcohol after staining with Ziehl-Neelsen stain. This property is due to the high lipid content in the cell wall of Mycobacterium tuberculosis. Alkali resistance (B) and alcohol resistance (C) are not specific properties of tuberculous bacilli. Capsule formation (D) is a characteristic of some bacteria but is not a defining feature of tuberculous bacilli.
You may also like to solve these questions
The process by which the nucleus of protozoans undergoes multiple divisions before the cell divides is called:
- A. budding
- B. mitosis
- C. schizogony
- D. fragmentation
Correct Answer: C
Rationale: Rationale: Schizogony is the process in protozoans where multiple nuclear divisions occur before cell division. This results in the formation of multiple daughter cells.
- A: Budding is a form of asexual reproduction where a new organism grows from an outgrowth on the parent.
- B: Mitosis is a type of cell division that results in two identical daughter cells.
- D: Fragmentation is a form of asexual reproduction where an organism breaks into fragments, each developing into a new organism.
Drug of first choice for the treatment of syphilis is:
- A. Gentamicin
- B. Penicillin
- C. Ciprofloxacin
- D. Chloramphenicol
Correct Answer: B
Rationale: The correct answer is B: Penicillin. Penicillin is the drug of first choice for treating syphilis due to its effectiveness in eradicating the bacterium Treponema pallidum, which causes syphilis. It is the most reliable treatment with well-established efficacy. Gentamicin (A), ciprofloxacin (C), and chloramphenicol (D) are not recommended for treating syphilis as they are not effective against the specific bacteria causing the infection. Penicillin remains the gold standard for syphilis treatment.
The cell envelope in gram positive bacteria is:
- A. Two-layer
- B. Three-layer
- C. One-layer
- D. There is no a cell envelope in gram-positive bacteria
Correct Answer: A
Rationale: The correct answer is A: Two-layer. In gram-positive bacteria, the cell envelope consists of two layers: the thick peptidoglycan layer and the cytoplasmic membrane. The peptidoglycan layer is much thicker compared to gram-negative bacteria, providing structural support and protection. The cytoplasmic membrane is located beneath the peptidoglycan layer and serves as a barrier between the cytoplasm and the external environment. The other choices are incorrect because gram-positive bacteria do have a cell envelope, it is composed of two layers, not three layers, and it is not just a single layer. Choice D is incorrect as it states that there is no cell envelope in gram-positive bacteria, which is not true.
Endotoxins are released upon:
- A. bacterial replication
- B. cell lysis of gram-negative bacteria
- C. antibody production
- D. formation of spores
Correct Answer: B
Rationale: The correct answer is B because endotoxins are part of the outer membrane of gram-negative bacteria. When these bacteria undergo cell lysis, the endotoxins are released, causing harmful effects. This process does not occur during bacterial replication (choice A), antibody production (choice C), or formation of spores (choice D). Bacterial replication involves the creation of new bacterial cells, not the release of endotoxins. Antibody production is the immune response to pathogens, not the direct cause of endotoxin release. Spores are dormant structures formed by some bacteria, which are not directly related to the release of endotoxins.
What is a common characteristic of spore-forming bacteria?
- A. Resistance to heat and dehydration
- B. Ability to produce toxins
- C. Presence of flagella
- D. Ability to photosynthesize
Correct Answer: A
Rationale: The correct answer is A: Resistance to heat and dehydration. Spore-forming bacteria form spores as a survival mechanism in harsh conditions. These spores are highly resistant to heat and dehydration, allowing the bacteria to withstand extreme environments. This characteristic is essential for their long-term survival and ability to persist in unfavorable conditions. Choices B, C, and D are incorrect because not all spore-forming bacteria produce toxins, have flagella, or are capable of photosynthesis. These characteristics are not exclusive to spore-forming bacteria and do not define them as a group.