Nokea
What is the function of CD14 with respect to LPS recognition?
- A. It is an accessory protein that allows the transport of newly synthesized TLR-4 onto the cell membrane
- B. It is a cytosolic protein that binds LPS that has been internalized via TLR-4/MD-2
- C. It acts as an adaptor in the TLR-4 signaling pathway
- D. It is expressed on the cell membrane and shuttles LPS to the vicinity of TLR-4/MD-2
Correct Answer: D
Rationale: The correct answer is D because CD14 is a glycosylphosphatidylinositol (GPI)-anchored protein expressed on the cell membrane that binds to LPS and facilitates its delivery to the TLR-4/MD-2 complex for recognition. CD14 does not transport TLR-4 (Choice A), bind LPS internally (Choice B), or act as an adaptor in the signaling pathway (Choice C). The key role of CD14 is to shuttle LPS to TLR-4/MD-2, initiating the immune response.
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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.
Based on studies of 16S ribosomal RNA and cell wall composition, which of the following bacteria are classified as Archaea?
- A. Halobacterium
- B. Methanococcus
- C. Sulfolobus
- D. Desulfovibrio
Correct Answer: D
Rationale: The correct answer is D: Desulfovibrio. Archaea are distinguished by their unique 16S ribosomal RNA sequences and cell wall composition. Desulfovibrio belongs to the Archaea domain due to its 16S rRNA sequence similarity and lack of peptidoglycan in the cell wall. Halobacterium, Methanococcus, and Sulfolobus are all classified as Archaea based on these criteria, making them incorrect choices.
Which of the following is the most severe complication among clients with allergies,regardless of type?
- A. Bronchitis
- B. Cardiac arrest
- C. Anaphylactic shock and angioneurotic edema
- D. Asthma and nasal polyps
Correct Answer: C
Rationale: Anaphylactic shock and angioneurotic edema are life-threatening allergic reactions that require immediate medical intervention.
Which of the following symptoms is associated with AIDS-related distal sensory polyneuropathy (DSP)?
- A. Staggering gait and muscle incoordination
- B. Abnormal sensations such as burning and numbness
- C. Delusional thinking
- D. Incontinence
Correct Answer: B
Rationale: Distal sensory polyneuropathy (DSP) in AIDS patients often presents with abnormal sensations like burning and numbness in the extremities.
An older adult has fallen and sprained his ankle in a local park. Which action should the responder perform first?
- A. Elevate the foot.
- B. Apply ice.
- C. Administer aspirin.
- D. Assist the patient with ambulation.
Correct Answer: A
Rationale: The correct action is to elevate the foot first. Elevating the foot helps reduce swelling and pain by promoting better circulation. This step is crucial in the initial management of a sprained ankle. Applying ice and administering aspirin can come after elevating the foot. Assisting with ambulation should only be considered after the initial measures are taken to address the sprained ankle.