Nokea
What is the diversity of pattern recognition receptors (PRRs) like?
- A. Highly diverse due to somatic recombination
- B. Limited because they are germline-encoded
- C. Constantly changing in response to infections
- D. Specific to individual antigens
Correct Answer: B
Rationale: The correct answer is B because pattern recognition receptors (PRRs) are encoded in the germline, meaning they are genetically determined and do not change during an individual's lifetime. This ensures consistency in detecting various pathogens across different individuals. Choices A, C, and D are incorrect because PRR diversity is not influenced by somatic recombination, does not change constantly in response to infections, and is not specific to individual antigens.
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What is the prevalence of sarcoidosis in Ireland?
- A. One of the lowest globally
- B. Among the highest globally
- C. Similar to the global average
- D. Extremely rare
Correct Answer: B
Rationale: The correct answer is B: Among the highest globally. Sarcoidosis prevalence in Ireland is relatively high compared to other regions. This is due to genetic factors, environmental influences, and possibly healthcare practices. Sarcoidosis rates vary worldwide, with Ireland being noted for its higher prevalence. Choices A, C, and D are incorrect because Ireland's sarcoidosis prevalence is not among the lowest globally, similar to the global average, or extremely rare.
The major role of the complement system is to work in conjunction with
- A. antibodies to lyse cells via the C8 and C9 components
- B. the major histocompatibility complex for cell recognition
- C. antibodies to opsonize cells
- D. the T-cell receptor for production of lymphokines
Correct Answer: A
Rationale: Rationale: The complement system is a group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens. Choice A is correct because the C8 and C9 components of the complement system form the membrane attack complex which lyses cells. Choices B, C, and D are incorrect because the complement system primarily functions independently of the major histocompatibility complex, antibodies for opsonization, and T-cell receptor for lymphokine production.
In the 1960s, smallpox was endemic:
- A. In many developing countries
- B. In North America
- C. In England
- D. Globally
Correct Answer: A
Rationale: The correct answer is A: In many developing countries. Smallpox was indeed endemic in many developing countries in the 1960s, causing significant morbidity and mortality. This is supported by historical records and epidemiological data from that time period. Choices B, C, and D are incorrect because smallpox was not endemic in North America, England, or globally during the 1960s. Smallpox eradication efforts led to the global eradication of the disease in 1980, but in the 1960s, it was still prevalent in many developing countries.
To raise antibodies that interfere with the interaction of HIV with CD4+ T cells, vaccines should target which of the following HIV antigens
- A. gp41
- B. Reverse transcriptase
- C. gp120
- D. Matrix proteins
Correct Answer: C
Rationale: The correct answer is C: gp120. This is because gp120 is a key HIV antigen that plays a crucial role in binding to CD4 receptors on T cells, facilitating viral entry. By targeting gp120, vaccines can induce antibodies that block this interaction, preventing HIV from infecting CD4+ T cells. Conversely, choices A, B, and D (gp41, Reverse transcriptase, Matrix proteins) are not as effective targets for interfering with the CD4+ T cell interaction, as they do not directly impact the initial binding and entry process of HIV into the cells.
The nurse is reinforcing teaching to a person being tested for HIV in a clinic. Which test should the nurse explain is done first in HIV testing?
- A. ELISA test
- B. Western blot test
- C. Viral load studies
- D. Rheumatoid factor test
Correct Answer: A
Rationale: The correct answer is A: ELISA test. The ELISA test is typically the initial screening test for HIV due to its high sensitivity in detecting HIV antibodies. It is cost-effective and quick. Western blot test is a confirmatory test used if ELISA is positive. Viral load studies monitor the progression of the disease but are not typically done first. Rheumatoid factor test is unrelated to HIV testing. Therefore, the ELISA test is the most appropriate initial step in HIV testing.