Nokea
The virus most commonly transmitted during pregnancy is:
- A. cytomegalovirus
- B. HIV
- C. herpes simplex virus
- D. Epstein-Barr virus
Correct Answer: A
Rationale: The correct answer is A: cytomegalovirus. CMV is the most common virus transmitted during pregnancy, leading to potential serious complications for the fetus. It can cause birth defects, hearing loss, and developmental delays. CMV is commonly spread through bodily fluids. HIV (B) can also be transmitted during pregnancy but is less common. Herpes simplex virus (C) can be transmitted but typically results in localized infection. Epstein-Barr virus (D) is not commonly transmitted during pregnancy.
You may also like to solve these questions
When examining a patient presumptively diagnosed with food toxicoinfection, a doctor on duty has detected symptoms characteristic of botulism. The patient named the meals he ate the day before. What is the most probable cause of infection?
- A. Homemade canned meat
- B. Custard pastry from a private bakery
- C. Sour cream from a local dairy factory
- D. Strawberries from a suburban vegetable garden
Correct Answer: A
Rationale: The correct answer is A: Homemade canned meat. Botulism is caused by the Clostridium botulinum bacteria, which thrives in low-oxygen environments like improperly canned food. Homemade canned meat poses a higher risk of contamination as it may not have been processed correctly, allowing the bacteria to grow and produce toxins. Custard pastry, sour cream, and strawberries are less likely to cause botulism as they are not typically associated with the bacteria unless improperly handled or stored. Homemade canned meat is the most probable cause based on the characteristic symptoms of botulism and the conditions that favor the growth of Clostridium botulinum in canned food.
Tuberculosis can be treated by means of combined chemotherapy that includes substances with different mechanisms of action. What antituberculous medication inhibits transcription of RNA into DNA in mycobacteria?
- A. Rifampicin
- B. Isoniazid
- C. Streptomycin
- D. Ethionamide
Correct Answer: A
Rationale: Rifampicin is the correct answer because it inhibits RNA transcription in mycobacteria by binding to the bacterial RNA polymerase. This prevents the synthesis of RNA, leading to the inhibition of protein production essential for bacterial growth.
Isoniazid inhibits mycolic acid synthesis, Streptomycin inhibits protein synthesis, and Ethionamide disrupts mycolic acid synthesis. These mechanisms are different from inhibiting RNA transcription, making them incorrect choices.
The Staphylococcus aureus toxin, which can cause scalded skin syndrome (SSS), is:
- A. hemolysis
- B. enterotoxin
- C. leucocidin
- D. epidermolytic toxin
Correct Answer: D
Rationale: The correct answer is D: epidermolytic toxin. This toxin specifically targets the epidermis, leading to exfoliation seen in scalded skin syndrome (SSS). Hemolysis (A) refers to the destruction of red blood cells, not relevant to SSS. Enterotoxins (B) cause food poisoning, not SSS. Leucocidins (C) target white blood cells, not pertinent to SSS. Therefore, the epidermolytic toxin (D) is the correct choice for causing SSS.
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.
Slime, blood and protozoa 30-200 microns of length have been revealed in a man's feces. The body is covered with cilias and has correct oval form with a little bit narrowed forward and wide round shaped back end. On the forward end a mouth is visible. In cytoplasm there are two nucleuses and two short vacuoles. For whom are the described attributes typical?
- A. Balantidium
- B. Lamblia
- C. Dysenteric amoeba
- D. Trichomonas
Correct Answer: A
Rationale: Rationale: The described attributes match those of Balantidium. The presence of cilia, oval shape with a narrowed front and wide back end, visible mouth, two nucleuses, and short vacuoles are all characteristic features of Balantidium. Balantidium is a ciliated protozoan parasite commonly found in the human intestine. The other choices can be eliminated based on specific characteristics: Lamblia lacks cilia and has a different shape, Dysenteric amoeba typically has a single nucleus, and Trichomonas does not have cilia or multiple nuclei. Therefore, based on the specific attributes described, the correct answer is Balantidium (Choice A).