Nokea
EcoRI restriction endonuclease reactions produce fragments with
- A. 3' cohesive ends
- B. blunt ends
- C. 5' cohesive ends
- D. none of the options are correct
Correct Answer: C
Rationale: EcoRI recognizes the palindromic sequence GAATTC and cuts between G and A on both strands, producing 5' cohesive ends. Cohesive ends can base-pair with complementary ends, facilitating DNA ligation. Blunt ends (choice B) are produced by enzymes that cut both DNA strands at the same position. Choice A is incorrect as EcoRI produces 5' cohesive ends, not 3' cohesive ends. Choice D is incorrect as EcoRI does produce cohesive ends.
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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.
The patient is admitted from home with a stage II pressure ulcer. This wound is classified as a yellow wound using the red-yellow-black concept of wound care. What is the nurse likely to observe when she does her wound assessment?
- A. Serosanguineous drainage
- B. Adherent gray necrotic tissue
- C. Clean, moist granulating tissue
- D. Creamy ivory to yellow-green exudate
Correct Answer: B
Rationale: Yellow wounds typically exhibit adherent gray necrotic tissue, indicating partial-thickness tissue loss without slough or eschar.
One principal function of complement is to
- A. inactivate performs
- B. mediate the release of histamine
- C. Bind antibodies attached to cell surfaces and to lyse these cells
- D. phagocytize antigens
Correct Answer: C
Rationale: The correct answer is C because complement proteins bind antibodies attached to cell surfaces and cause cell lysis, enhancing immune response. Choice A is incorrect as complement does not inactivate performs. Choice B is incorrect as complement does not mediate the release of histamine. Choice D is incorrect as phagocytosis is a function of phagocytes, not complement proteins. Therefore, the correct function of complement is to enhance immune response by binding antibodies and causing cell lysis.
Which of the following best describes the relationship between innate and adaptive immunity?
- A. Innate immunity suppresses adaptive immunity
- B. Adaptive immunity enhances innate immune functions
- C. Innate immunity activates and stimulates adaptive immunity
- D. They function entirely independently of each other
Correct Answer: C
Rationale: The correct answer is C because innate immunity plays a crucial role in initiating and influencing adaptive immunity. Innate immunity activates and stimulates adaptive immune responses by recognizing pathogens and initiating the adaptive immune system to produce specific responses. This relationship is essential for the body's overall immune defense.
Choice A is incorrect because innate immunity does not suppress adaptive immunity; instead, they work together synergistically. Choice B is incorrect because adaptive immunity does not enhance innate immune functions, but rather complements them. Choice D is incorrect because innate and adaptive immunity are interconnected and work together to provide comprehensive immune protection.
Which of the following concerned with Leishmania is NOT true
- A. Meditated by IgE
- B. Is a unicellular parasite
- C. Activation of macrophages is essential for killing the parasite
- D. Escapes host immune attack by hiding inside neutrophils
Correct Answer: a
Rationale: The correct answer is A: Mediated by IgE. Leishmania infection is not primarily mediated by IgE antibodies. The immune response against Leishmania involves T cells, macrophages, and cytokines. IgE is not a major player in the defense against Leishmania. Choices B, C, and D are incorrect because Leishmania is indeed a unicellular parasite, activation of macrophages is essential for killing the parasite, and Leishmania can hide inside neutrophils to escape the host immune attack.