All of the following areas of the human body contain normal flora except:
- A. Peritoneum
- B. Urethra
- C. Vagina
- D. Mouth
Correct Answer: A
Rationale: The correct answer is A: Peritoneum. Normal flora refers to the microorganisms that naturally inhabit the human body without causing harm. The peritoneum is a sterile area, so it does not harbor normal flora. The urethra, vagina, and mouth all have normal flora due to their moist and warm environments, which provide an ideal habitat for microorganisms to thrive. The peritoneum, being a sterile cavity that houses organs like the stomach and intestines, does not have a natural microbial population like the other areas mentioned. Therefore, it does not contain normal flora.
You may also like to solve these questions
Which of the following is used to test for bacterial antibiotic susceptibility?
- A. Gram stain
- B. Catalase test
- C. Kirby-Bauer disk diffusion test
- D. Endospore stain
Correct Answer: C
Rationale: The correct answer is C: Kirby-Bauer disk diffusion test. This test is used to determine the antibiotic susceptibility of bacteria by measuring the zone of inhibition around antibiotic-soaked paper disks. It helps identify which antibiotics are effective against the bacteria being tested. This test is crucial in guiding antibiotic treatment decisions.
A: Gram stain is used to classify bacteria based on their cell wall composition and morphology, not for antibiotic susceptibility testing.
B: Catalase test is used to differentiate between catalase-positive and catalase-negative bacteria, not for antibiotic susceptibility testing.
D: Endospore stain is used to detect the presence of endospores in bacteria, not for antibiotic susceptibility testing.
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.
Adenoviruses have helical capsids:
- A. TRUE
- B. FALSE
- C. Both answers can be correct depending on the given situation
- D. None of the above
Correct Answer: B
Rationale: Step 1: Adenoviruses are known to have icosahedral capsids, not helical.
Step 2: Helical capsids are typically found in viruses like tobacco mosaic virus.
Step 3: Therefore, the statement that adenoviruses have helical capsids is FALSE.
Summary: A is incorrect as adenoviruses do not have helical capsids. C is incorrect as there is no situation where adenoviruses have helical capsids. D is incorrect as there is a clear correct answer, which is B.
The main function of bacterial ribosomes is:
- A. DNA replication
- B. protein synthesis
- C. cell wall synthesis
- D. RNA splicing
Correct Answer: B
Rationale: The correct answer is B: protein synthesis. Bacterial ribosomes are responsible for translating messenger RNA into proteins through a process called translation. Ribosomes are composed of both protein and RNA molecules and facilitate the binding of transfer RNA to the messenger RNA to assemble the amino acids in the correct order to form a protein. DNA replication (A) is carried out by enzymes such as DNA polymerase, not ribosomes. Cell wall synthesis (C) is a process involving enzymes that build the structure of the cell wall in bacteria. RNA splicing (D) is a eukaryotic process that involves removing introns from pre-mRNA molecules, which is not a function of bacterial ribosomes.
Etiological factors for the infectious diseases are often microorganisms with various ultrastructure. Which of the following microorganism groups relates to the eukaryotes?
- A. Protozoa
- B. Viruses
- C. Viroids
- D. Prions
Correct Answer: A
Rationale: The correct answer is A: Protozoa. Protozoa are eukaryotic microorganisms, meaning they have a true nucleus and membrane-bound organelles. This relates to the question as eukaryotes are organisms with complex cells containing these features. Viruses (B) are non-living entities that require a host cell to replicate, lacking cellular structures. Viroids (C) are smaller than viruses and consist of only RNA, lacking a protein coat. Prions (D) are misfolded proteins causing diseases but are not considered microorganisms nor do they have cellular structure. Thus, protozoa are the only eukaryotic microorganism group among the options.