Nokea
The phagocytosis is:
- A. Killing of bacterial cells with bactericidal antibiotics
- B. Blocking of key bacterial enzymes
- C. Active engulf and destruction of microorganisms by some host cells
- D. There is no correct answer
Correct Answer: C
Rationale: The correct answer is C because phagocytosis refers to the process where certain host cells engulf and destroy microorganisms. This is an essential mechanism of the immune system to eliminate pathogens. Choice A is incorrect because phagocytosis does not involve the use of antibiotics. Choice B is incorrect as it describes a different mechanism of action against bacteria. Choice D is incorrect because phagocytosis is a well-established biological process.
You may also like to solve these questions
The organism often called “flesh-eating bacteria†is:
- A. Staphylococcus aureus
- B. Staphylococcus epidermidis
- C. Streptococcus pyogenes
- D. Propionibacterium acnes
Correct Answer: C
Rationale: The correct answer is C: Streptococcus pyogenes. This bacterium is commonly known as "flesh-eating bacteria" due to its ability to cause severe tissue destruction and necrotizing fasciitis. Streptococcus pyogenes produces toxins that break down skin and muscle tissues. Staphylococcus aureus (A) can cause skin infections but is not typically associated with necrotizing fasciitis. Staphylococcus epidermidis (B) is a normal skin flora and rarely causes infections. Propionibacterium acnes (D) is associated with acne and not known for causing tissue destruction. Therefore, the correct choice is Streptococcus pyogenes due to its unique ability to cause severe tissue damage and necrotizing fasciitis.
Which of the following bacteria produces an endotoxin responsible for septic shock?
- A. Staphylococcus aureus
- B. Escherichia coli
- C. Neisseria meningitidis
- D. All of the above
Correct Answer: D
Rationale: The correct answer is D, "All of the above." Staphylococcus aureus, Escherichia coli, and Neisseria meningitidis all produce endotoxins that can lead to septic shock. Endotoxins are part of the outer membrane of Gram-negative bacteria, such as E. coli and N. meningitidis, which can trigger a severe immune response leading to septic shock. S. aureus, a Gram-positive bacterium, produces toxins that can also contribute to septic shock. Therefore, all of these bacteria can produce endotoxins responsible for septic shock. Choices A, B, and C are incorrect because they only identify individual bacteria that produce endotoxins, whereas the correct answer encompasses all bacteria listed.
A 42-year-old woman has foamy purulent vaginal discharges. Microscopy revealed flagellated protozoa with an undulating membrane and pear-shaped structure. What organism was found?
- A. Trichomonas vaginalis
- B. Trypanosoma gambiense
- C. Leishmania donovani
- D. Lamblia intestinalis
Correct Answer: A
Rationale: The correct answer is A: Trichomonas vaginalis. Trichomonas vaginalis is a sexually transmitted protozoan parasite that causes trichomoniasis, characterized by foamy purulent vaginal discharges. Microscopy of vaginal discharge showing flagellated protozoa with an undulating membrane and pear-shaped structure is indicative of Trichomonas vaginalis. Trypanosoma gambiense causes African sleeping sickness and is transmitted by tsetse flies. Leishmania donovani causes visceral leishmaniasis transmitted by sandflies. Lamblia intestinalis causes giardiasis and is characterized by diarrhea and flatulence.
Which statement for immunomodulators is correct
- A. they can only stimulate the incomplete humoral and immune response
- B. Isoniazid is a very effective immunomodulator
- C. they can be natural and artificial compounds
- D. they can only suppress the incomplete humoral and immune response
Correct Answer: C
Rationale: Rationale:
Choice C is correct because immunomodulators can indeed be natural (e.g., cytokines) or artificial compounds (e.g., synthetic peptides). They work by modulating the immune response, enhancing or suppressing it as needed.
Choice A is incorrect because immunomodulators can stimulate both humoral and cellular immune responses.
Choice B is incorrect as isoniazid is primarily an antibiotic used to treat tuberculosis, not an immunomodulator.
Choice D is incorrect because immunomodulators can have varying effects on the immune response, not just suppress it.
What is the function of bacterial pili?
- A. Provide motility
- B. Aid in adhesion
- C. Form spores
- D. Synthesize proteins
Correct Answer: B
Rationale: The function of bacterial pili is to aid in adhesion. Pili are hair-like structures on the bacterial surface that help the bacteria attach to surfaces or other cells. This adhesion is crucial for colonization and infection. Pili do not provide motility, as that is typically done by flagella. Bacteria form spores for survival under harsh conditions, and protein synthesis is carried out by ribosomes, not pili. Thus, the correct answer is B, aiding in adhesion.