Nokea
Hfr strains of bacteria:
- A. do not have an 'F' (fertility) factor.
- B. have an 'F' factor plasmid.
- C. have an 'F' factor integrated in the bacterial chromosome.
- D. transfer the genetic information to other bacteria with ow frequency.
Correct Answer: C
Rationale: The correct answer is C because Hfr strains of bacteria have the F factor integrated into their bacterial chromosome. This integration allows for the transfer of genetic material during conjugation. This integration results in a high frequency of genetic information transfer to recipient cells, which is a characteristic of Hfr strains.
Choice A is incorrect because Hfr strains do have the F factor, but it is integrated into their chromosome, not absent. Choice B is incorrect because Hfr strains do not just have an F factor plasmid; it is integrated into the chromosome. Choice D is incorrect because Hfr strains actually transfer genetic information with high frequency, not low frequency.
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As the nurse manager in a public health department,you are responsible for developing a plan to reduce the incidence of infection with the human immunodeficiency virus (HIV) in the community. Which nursing action is best delegated to health assistants working for the agency?
- A. Supply injection drug users with bleach solution for cleaning needles and syringes.
- B. Provide pretest and post-test counseling to those patients who are seeking HIV testing.
- C. Educate high-risk community members about the use of condoms in HIV prevention.
- D. Determine which population groups to target for education based on community assessment.
Correct Answer: A
Rationale: Health assistants can effectively distribute bleach solutions to injection drug users as part of harm reduction strategies. Pretest and post-test counseling education on condom use and community assessment require more advanced training and are typically responsibilities of registered nurses or other healthcare professionals.
Which cells are involved in innate immunity?
- A. B lymphocytes
- B. T lymphocytes
- C. Natural killer cells
- D. Plasma cells
Correct Answer: C
Rationale: The correct answer is C: Natural killer cells. Natural killer cells are part of the innate immune system and play a crucial role in identifying and destroying infected or abnormal cells. They are able to recognize and target cells that lack specific markers, providing a rapid response to infections.
Explanation for incorrect choices:
A: B lymphocytes are part of the adaptive immune system, not innate immunity.
B: T lymphocytes are also part of the adaptive immune system, not involved in innate immunity.
D: Plasma cells are differentiated B cells that produce antibodies in the adaptive immune response, not part of innate immunity.
Which of the following statements is most correct regarding Leishmania?
- A. Leishmaniasis is caused by an extracellular bacterium
- B. Leishmaniasis is associated with severe immunodeficiency
- C. An infected individual is less likely to suffer severe leishmaniasis if they make a TH2 rather than TH1 response to the pathogen
- D. Visceral leishmaniasis is the most severe form of leishmaniasis
Correct Answer: D
Rationale: The correct answer is D because visceral leishmaniasis is indeed the most severe form of leishmaniasis. Visceral leishmaniasis affects internal organs and can be fatal if left untreated.
A is incorrect because Leishmania is a protozoan parasite, not a bacterium. B is incorrect because leishmaniasis can affect individuals with normal immune systems, not just those with severe immunodeficiency. C is incorrect because a TH1 response is actually protective against severe leishmaniasis, not a TH2 response.
To what is the increase in emerging and untreatable infections attributed (select all that apply)?
- A. The evolution of new infectious agents
- B. Use of antibiotics to treat viral infections
- C. Human population encroachment into wilderness areas
- D. Transmission of infectious agents from humans to animals
Correct Answer: A
Rationale: The correct answer includes options A, B, C, and E. The evolution of new infectious agents, inappropriate use of antibiotics, human encroachment into wilderness areas, and an increased number of immunosuppressed individuals contribute significantly to the rise in untreatable infections. Transmission from humans to animals is less relevant compared to zoonotic transmission from animals to humans.
What is the role of macrophages in granuloma formation?
- A. Neutralizing histamine
- B. Engulfing antigens but failing to destroy them
- C. Stimulating IgE production
- D. Producing antibodies against antigens
Correct Answer: B
Rationale: The correct answer is B because macrophages play a crucial role in granuloma formation by engulfing antigens but failing to destroy them, leading to the formation of a cluster of immune cells to contain the persistent antigen. Macrophages present antigens to T cells, triggering an immune response. Other choices are incorrect as macrophages do not neutralize histamine, stimulate IgE production, or produce antibodies against antigens in the context of granuloma formation.