Nokea
Which of the following statements is NOT true about influenza viruses?
- A. they are spherical viruses coated with a lipoprotein coat
- B. hemagglutinin and neuraminidase of flu viruses are antigenically variable
- C. the susceptibility of the population to influenza viruses is high
- D. there is no specific prophylaxis available
Correct Answer: D
Rationale: The correct answer is D because there is specific prophylaxis available for influenza, such as the flu vaccine. Choice A is incorrect as influenza viruses are not spherical, they are typically pleomorphic. Choice B is incorrect because hemagglutinin and neuraminidase are indeed antigenically variable, contributing to the need for annual flu vaccines. Choice C is incorrect as the susceptibility of the population to influenza viruses can vary depending on factors such as immunity and vaccination status.
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Which bacteria is responsible for causing cholera?
- A. Shigella dysenteriae
- B. Vibrio cholerae
- C. Salmonella enterica
- D. Clostridium perfringens
Correct Answer: B
Rationale: The correct answer is B: Vibrio cholerae. Cholera is caused by this specific bacterium due to its production of cholera toxin, leading to severe watery diarrhea. Shigella dysenteriae causes dysentery, Salmonella enterica causes salmonellosis, and Clostridium perfringens causes food poisoning, none of which present with the characteristic symptoms of cholera.
A 9 y.o. child has been taking antibiotics on account of bronchopneumonia for a long time. There appeared pain and burning in the area of mucous membrane of his lips and tongue. Objectively: mucous membrane of lips and tongue has caseous and grey plaques that can be easily removed by a spatula leaving hyperemia foci on their spot. Microscopic examination of the plaques revealed mycelium. What is the most probable diagnosis?
- A. Candidous cheilitis
- B. Exfoliative cheilitis
- C. Leukoplakia
- D. Contactant allergic cheilitis
Correct Answer: A
Rationale: The most probable diagnosis is A: Candidous cheilitis. Candidous cheilitis is a fungal infection caused by Candida species. In this case, the presence of mycelium on the plaques indicates a fungal infection. The symptoms of pain, burning, and grey plaques that can be easily removed leaving hyperemia are typical for Candidous cheilitis. Choice B (Exfoliative cheilitis) is characterized by scaling and peeling of the lips, not plaques with mycelium. Choice C (Leukoplakia) is a precancerous condition causing white plaques that cannot be easily removed. Choice D (Contactant allergic cheilitis) is an allergic reaction causing inflammation, not fungal plaques.
As an example of specific human parasites one can name Plasmodium falciparum, human pinworm and some others. The source of parasite invasion is always a human. Such specific human parasites cause the diseases that are called:
- A. Anthroponoses
- B. Zoonoses
- C. Anthropozoonoses
- D. Infections
Correct Answer: A
Rationale: The correct answer is A: Anthroponoses. This term refers to diseases caused by specific human parasites that are transmitted directly from human to human. In this case, the source of parasite invasion is always a human host. This term specifically describes diseases caused by parasites that exclusively infect humans.
Choice B: Zoonoses refers to diseases that can be transmitted from animals to humans. Choice C: Anthropozoonoses is a combination of zoonoses and anthroponoses, which is not applicable in this scenario. Choice D: Infections is a general term that does not specify the source or type of parasite causing the disease.
The correct descending order of taxonomic categories is
- A. species, domain, phylum, kingdom, order, division, class, genus
- B. domain, kingdom, phylum, class, family, order, genus, species
- C. domain, kingdom, phylum, class, order, family, genus, species
- D. kingdom, domain, phylum, order, class, family, genus, species
Correct Answer: C
Rationale: The correct descending order of taxonomic categories is domain, kingdom, phylum, class, order, family, genus, species. This hierarchical classification system helps organize and categorize living organisms based on their shared characteristics and evolutionary relationships.
Explanation:
- Domain is the broadest category, representing the highest level of classification.
- Kingdom further divides organisms into major groups based on similar characteristics.
- Phylum, class, order, family, and genus successively narrow down the classification based on more specific shared characteristics.
- Species is the most specific category, representing individual organisms capable of interbreeding.
Summary of other choices:
A: Incorrect as it has the incorrect order of phylum, kingdom, and division.
B: Incorrect as it has the incorrect order of family and species.
D: Incorrect as it has the incorrect order of domain, kingdom, and class.
Which of the following bacteria should be handled in a Biosafety Level 2 facility?
- A. Micrococcus luteus
- B. Bacillus subtilis
- C. Salmonella
- D. Staphylococcus epidermidis
Correct Answer: C
Rationale: The correct answer is C: Salmonella. This bacterium should be handled in a Biosafety Level 2 facility due to its potential to cause disease in humans. Salmonella is a pathogenic bacterium that can cause foodborne illnesses and infections. Handling it in a Biosafety Level 2 facility ensures proper containment and protection of personnel.
A: Micrococcus luteus and B: Bacillus subtilis are common environmental bacteria that do not pose significant risks to human health, so they can be safely handled in lower biosafety levels.
D: Staphylococcus epidermidis is a common skin commensal bacterium that is generally not considered highly pathogenic, so it does not require Biosafety Level 2 containment.