Explain the tuberculin test, including visual identification and immunological interpretation of positive and negative results, and describe why a positive test does not indicate an active infection
What will be an ideal response?
Answer: The tuberculin test is a test performed to identify exposure to Mycobacterium tuberculosis, the causative agent of tuberculosis. The tuberculin skin test looks for hypersensitivity specific to tuberculin, a protein unique to M. tuberculosis. A local immune inflammatory response is elicited from tuberculin exposure to a hypersensitive individual within 1-3 days at the tuberculin-exposed area. This positive test result does not necessarily mean that the individual is currently infected by M. tuberculosis. A healthy person previously exposed to the pathogen could also show a positive test result, because the cell-mediated immunity is lifelong. A negative tuberculin test result is indicated by a lack of induration and edema at the intradermal injection site and suggests the individual has never been exposed to M. tuberculosis.
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Which of the following correctly lists the stages of human development?
A. fertilized egg, blastocyst, gastrula, morula B. fertilized egg, blastocyst, morula, gastrula C. fertilized egg, morula, blastocyst, gastrula D. fertilized egg, morula, gastrula, blastocyst E. fertilized egg, gastrula, morula, blastocyst
When a protist digests its food, particles to be broken down are isolated from the rest of the cell in a ____ , to which digestive enzymes are added
Fill in the blank with the appropriate word.
Ribozymes
A. are complexes of ribosomes and RNA. B. are self-catalytic RNA. C. suggest that nucleic acids evolved before proteins. D. are enzymes that degrade RNA and therefore have potential for clinical applications. E. are self-catalytic RNA AND suggest that nucleic acids evolved before proteins.
To mobilize more glucose during fasting,
A. only glucagon will increase. B. cortisol, epinephrine, and glucagon will all increase. C. only glucagon and cortisol will increase. D. only cortisol will increase. E. only epinephrine will increase.