What is the purpose of using PCR (polymerase chain reaction) in the laboratory?
To separate DNA fragments by size.
To amplify specific regions of DNA.
To sequence DNA fragments.
To analyze protein expression levels.
The Correct Answer is B
PCR (polymerase chain reaction) is a laboratory technique used to make many copies of a specific region of DNA.
The goal of PCR is to make enough of the target DNA region that it can be analyzed or used in some other way.
PCR has many research and practical applications, including DNA cloning, medical diagnostics, and forensic analysis of DNA.
Choice A is incorrect because PCR does not separate DNA fragments by size. Choice C is incorrect because PCR does not sequence DNA fragments.
Choice D is incorrect because PCR does not analyze protein expression levels.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
Pattern recognition receptors (PRRs) are a class of receptors that can directly recognize the specific molecular structures on the surface of pathogens.
PRRs play a crucial role in the proper function of the innate immune system and are germline-encoded host sensors, which detect molecules typical for the pathogens.
Choice B is incorrect because cytokines are not receptors but rather signaling molecules that regulate immunity.
Choice C is incorrect because chemokines are not receptors but rather signaling molecules that attract immune cells to sites of infection.
Choice D is incorrect because T cells are not receptors but rather white blood cells that assist B cells or directly kill infected cells.
Correct Answer is C
Explanation
Inflammatory cytokines released during the early response to bacterial infection play a crucial role in initiating cell recruitment and local inflammation 1.
They induce the expression of adhesion molecules in endothelial cells and promote the recruitment of neutrophils to the site of inflammation 1.
Choice A is incorrect because while inflammatory cytokines may enhance phagocytosis, they do not directly disrupt the infection.
Choice B is incorrect because inflammatory cytokines do not directly attack invading pathogens.
Choice D is incorrect because inflammatory cytokines do not secrete antibodies to neutralize pathogens.
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